Soil Builder vs Garden Cover Up Mix – which is best for your garden?
Both of our cover crop mixes give you multiple benefits in the soil and above it. You can’t go wrong with either one. The Garden Cover Up mix is a general use cover crop, while the Soil Builder mix is more specific toward improving the overall condition of your soil.
Cover crops improve soil in a number of ways. They protect against erosion while increasing organic matter and catch nutrients before they can leach out of the soil. Legumes add nitrogen to the soil. Their roots help unlock nutrients, converting them to more available forms. Cover crops provide habitat or food source for important soil organisms, break up compacted soil layers, help dry out wet soils and maintain soil moisture in arid climates.
It’s always a good idea to maintain year-round soil cover whenever possible, and cover crops are the best way.
Let’s look at how cover crops work overall, then we’ll see the differences of each mix.
Most cover crop mixes are legumes and grains or grasses. Each one has a different benefit to the soil. Legumes include alfalfa, clover, peas, beans, lentils, soybeans and peanuts. Well-known grains are wheat, rye, barley and oats which are used as grasses for animal forage.
Legumes help reduce or prevent erosion, produce biomass, suppress weeds and add organic matter to the soil. They also attract beneficial insects, but are most well-known for fixing nitrogen from the air into the soil in a plant-friendly form. They are generally lower in carbon and higher in nitrogen than grasses, so they break down faster releasing their nutrients sooner. Weed control may not last as long as an equivalent amount of grass residue. Legumes do not increase soil organic matter as much as grains or grasses. Their ground cover makes for good weed control, as well as benefiting other cover crops.
Rye Cover Crop
Grains or grasses
Grain or grass cover crops help retain nutrients–especially nitrogen–left over from a previous crop, reduce or prevent erosion and suppress weeds. They produce large amounts of mulch residue and add organic matter above and below the soil, reducing erosion and suppressing weeds. They are higher in carbon than legumes, breaking down slower resulting in longer-lasting mulch residue. This releases the nutrients over a longer time, complementing the faster-acting release of the legumes.
This pretty well describes what our Garden Cover Up mix does, as it is made up of 70% legumes and 30% grasses.
Our Soil Builder mix takes this approach a couple of steps further in the soil improvement direction with the addition of several varieties known for their benefits to the soil structure, micro-organisms or overall fertility.
For example, the mung bean is a legume used for nitrogen fixation and improving the mycorrhizal populations, which increase the amount of nutrients available to each plant through its roots.
Spring Sunflower
Sunflowers are renowned for their prolific root systems and ability to soak up residual nutrients out of reach for other commonly used covers or crops. The bright colors attract pollinators and beneficials such as bees, damsel bugs, lacewings, hoverflies, minute pirate bugs, and non-stinging parasitic wasps.
Safflower has an exceptionally deep taproot reaching down 8-10 feet, breaking up hard pans, encouraging water and air movement into the soil and scavenging nutrients from depths unreachable to most crops. It does all of this while being resistant to all root lesion nematodes. Gardeners growing safflower usually see low pest pressure and an increase in beneficials such as spiders, ladybugs and lacewings.
Now you see why you can’t go wrong in choosing one of our cover crop mixes! Both greatly increase the health and fertility of the soil, along with above-ground improvements in a short time. Even if you only have a month, the Garden Cover Up mix will impress you for the next planting season.
For a general approach with soils that need a boost but are still producing well, the Garden Cover Up mix is the best choice. Our Soil Builder mix is for rejuvenating a dormant bed or giving some intensive care to a soil that has struggled lately. Both will give you a serious head start in establishing a new growing area, whether it is for trees, shrubs, flowers, herbs or vegetables.
Let one of our cover crops go to bat for you and see what happens when you play on Mother Nature’s team!
https://underwoodgardens.com/wp-content/uploads/2017/06/Cover-Crop-Mix.jpg478850Stephen Scotthttps://underwoodgardens.com/wp-content/uploads/2019/06/Survey-Header.jpgStephen Scott2017-06-28 17:41:502024-06-23 15:20:33Which cover crop mix is best for me?
With a little knowledge and a tiny bit of preparation, you can grow lettuce throughout the summer without bolting. Imagine serving your own fresh-harvested, garden-grown lettuce throughout the summer!
First, some knowledge
Lettuce is a cool-season vegetable, meaning it grows best in temperatures around 60 – 65°F. Once temperatures rise above 80°F, lettuce will normally start to “bolt” or stop leaf production and send up a stalk to flower and produce seed. The leaves become bitter at this stage.
This is because the mainstay of our beloved salads is not a North American native, but an ancient part of our dinner table. Belonging to the daisy family, lettuce was first grown by Egyptians around 4,700 years ago. They cultivated lettuce from a weed used only for its oil-rich seeds to a valued food with succulent leaves that nourished both the mind and libido. Images in tombs of lettuce being used in religious ceremonies show its prominent place in Egyptian culture.
The earliest domesticated form resembled a large head of Romaine lettuce, which was passed to the Greeks and then the Romans. Around 50 AD, Roman agriculturalist Columella described several lettuce cultivars, some of which are recognizable as ancestors to our current favorites. Even today, Romaine types and loose-leaf lettuces tolerate heat better than tighter heading lettuces like Iceberg.
Three factors to growing lettuce in summer
Two factors cause lettuce to bolt and become bitter – temperature and sun exposure.
The temperatures you are concerned about are both air and soil, as a lettuce plant (or any garden plant for that matter) tolerates a higher air temperature if the soil around its roots is cool and moist. Ensuring a cool and damp soil gives you more air temperature leeway. Because lettuce has wide and shallow roots, a drip system on a timer teamed up with a thick mulch keeps it happier in warm weather.
Shade is the third part to keeping lettuce growing vigorously later into warm weather. Reducing sun exposure lowers the heat to the leaves, but also to the soil and roots – creating a combined benefit. Deep shade isn’t good, but a systemallowing sun during the morning while sheltering the plants in the afternoon keeps your salad machines going much longer than you thought possible.
One last bit of knowledge. Most lettuce seeds become dormant (won’t germinate) as temperatures rise above 80°F, a condition called”thermo-inhibition”. This trait is a carryover from wild lettuce in the Mediterranean Middle East, where summers are hot with little moisture. If the lettuce seeds sprouted under these conditions, they would soon die out and the species would go extinct.
Thanks to research, there are some easy techniques to germinate lettuce seeds in warm weather – our article Improve Lettuce Seed Germination shows you how. Now you’ll be able to start lettuce when no one else can!
The three most effective elements in keeping your lettuce producing during warm weather are a drip system on a timer, a good bed of mulch and shade. Let’s look at each one and how they help.
Lettuce growing with mulch, shade & drip system
A drip system on a timer maintains moisture levels much more evenly than hand watering, and the timer can be set for how much and how often water is needed. Checking the soil moisture levels is easy – just push your finger into the soil up to the second knuckle. If the soil feels moist and spongy the moisture is perfect for lettuce. Adjust the number and length of watering each time up or down to maintain this level. From experience, we usually start the timer once a day for 10 minutes in the spring and go to 2 and sometimes 3 times a day for 10 minutes during the heat of the summer. As the weather cools down, we decrease the amount of water accordingly.
This minimizes water stress on all your garden plants, not just lettuce. When the roots have moisture, they can withstand the heat and drying effects better without losing health and slowing production.
A thick bed of mulch reduces moisture loss at the surface of the soil from heat and breezes. Here in central Arizona, it’s not uncommon to have a 15-mph breeze with 90°F+ with 5 – 10% humidity levels. Basically, we garden in a giant hair-dryer!
We use two inches of wood chip mulch, but straw also works well and some gardeners have good success with well-aged compost. With mulch, the soil moisture levels are at the top of the soil where it meets the mulch. Without it, the moisture doesn’t appear until you’ve dug down at least two inches, with three inches having the same amount of moisture as the surface does with mulch. Another benefit of wood chip mulch is it provides needed nutrients to the soil and encourages earthworms and other beneficial soil life as it decomposes. The beds where we’ve put wood chips down have three times the amount of earthworm activity as those that have only compost or nothing at all.
The third element is shade, which might seem daunting but is surprisingly simple to provide. Shade can be from various sources – a living trellis of cucamelon, vine peach or Malabar spinach; a row of tall sunflowers on thewest side of the bed; a container garden on the east side of the house or garage to capture afternoon shade, or a shade cloth structure on the west side of the bed or over a container or raised bed. Trees can also give partial shade – grow on the east side to take advantage of shade during the hotter, more stressful afternoons.
Real world examples
You might be thinking – this all sounds great, but does it work?
Here are two examples showing that it does:
The first example is a study conducted by Kansas City area growers in cooperation with Kansas State University and the Organic Farming Research Foundation.
This project was conducted to test practical methods for extending the production of cool season leafy greens into the hot summer months in Kansas City, where high temperatures normally terminate production of these crops from June through August. We used high tunnels covered with 40% shade cloth, combined with drip irrigation and were able to produce crops of lettuce (10 cultivars) and Asian greens (5 types) throughout the summer. Trials were conducted at three locations, two of them working organic farms, and the other an agricultural experiment station in order to produce statistically valid experimental results.
We produced higher yields of marketable quality lettuce and greens over multiple harvests throughout the summer compared to outside plots, which produced lower yields of poorer quality crops.
As a result of this project, both growers have continued with summer greens production, recognizing that adapted warm-season vegetables may be more profitable under hot summer conditions. *1
The second example is a two-season grow-out test by the Sacramento County Master Gardeners at their Fair Oaks Horticulture Center during the summers of 2015 and 2016.
Grow loose leaf varieties that are heat-resistant or slow-bolting, rather than varieties that form heads.
Provide shade. Use shade cloth or plant on the shady side of taller vegetables.
Don’t skimp on water. Keep lettuce growing fast to prevent wilting, premature bolting, and bitterness.
Mulch lightly with an organic mulch to retain soil moisture.
Use cut-and-come-again harvesting of outer leaves.
Make successive plantings with transplants to replace spent plants.
During the season, replenish soil nitrogen to encourage growth. We used a mild liquid fish emulsion fertilizer.
Inspect plants for insects and diseases. Hand pick and destroy destructive insects. Remove diseased leaves or plants.
Merlot- 42 days to bolting – Dense heads of ruffled red leaves
Jericho – 73days to bolting -Romaine variety from Israel. *2
Easy shade for your garden beds
Here’s a quick and easy way to shade any container, raised bed or row in your garden:
Simple lettuce shade structure
Use 1/2 inch PVC pipe from any hardware store. 1/2 inch is the least expensive and easiest to work with for this use.
Shade structure detail
Using PVC elbows, simply insert the tubing into the elbow and push the uprights into the soil at the edge of the planter or raised bed. No glue needed, so they can be taken down and re-used next season.
Planter with shade system
We used some leftover shade cloth from another project and cable ties to secure the shade cloth to the PVC tubing.
Shade cloth canopy
The front of the shade canopy is left loose so we can harvest easily.
Lettuce shade detail
The right half of the lettuce is shaded, with the left half getting shade as the day progresses.
Now you have the tools and knowledge, so plan on successfully growing lettuce after everyone else has given up this season! As your accomplishments are recognized and compliments roll your way – make sure to share your tools and spread the success.
Update – Three Weeks Later
Lettuce after 3 weeks of heat
Our lettuce looks amazing, considering we’ve had continuous temperatures above 95°F for the past 13 days and above 100°F for the past 9 days. The Sweet & Spicy Mix hasn’t slowed down and is robust, crunchy, and still sweet with no bitter flavors. The growth is easy to see, comparing to the above photos.
Lettuce after 3 weeks of heat – detail of leaves
Looking closer, it isn’t perfect. There are some small holes and some of the leaf edges are a little toasty, but these conditions are so far outside of lettuce comfort zone, it’s like growing on Mars!
Lettuce normally starts to bolt at 80°F, but this has not only survived, but thrived at over 100°F for more than a week and more than 90°F for almost two weeks, this is a technique you should try.
References
1 – Outcome of Shade-covered high tunnels for summer production of lettuce and leafy greens | Organic Farming Research Foundation, Shade-covered high tunnels for summer production of lettuce and leafy greens,
2 – Growing Lettuce in Warm Weather – Sacramento MGs, Growing Lettuce in Warm Weather, http://sacmg.ucanr.edu/summer_lettuce/, University of California, Division of Agriculture and Natural Resources
We’ve greatly enjoyed our own homegrown sprouts for the past several years. There’s just something about their fresh taste and crispy crunch that can be enjoyed any time of year, no matter the weather.
As with all our seeds, we make sure we know who our growers are and where our seeds come from. This is even more important with seeds used for sprouting as they are eaten directly as a food.
We chose our sprouting seeds supplier because of their commitment to the safest and healthiest seeds possible. They showed us their safety standards and testing protocols and we want to share them with you.
Growing your own sprouts at home is much safer than buying them off the shelf at a supermarket, and we’ll show you why.
-The safest sprouts are those you grow at home in a glass jar from a trusted, reliable source that screens the seed and tests both the irrigation water and sprouts for contamination.
-The next best is fresh sprouts from a local, trusted grower who buys their seed from a similar source as above.
-The least safe sprouts are from the supermarket where they have most likely been grown in a different state and trucked in. These sprouts are usually more than a few days old when they are first put on the shelves.
Sprouts are healthy, nutritious and are rich in vitamins, minerals, proteins, enzymes, bioflavonoids, antioxidants, phytoestrogens, glucosinolates and other phytochemicals. They are an excellent alternative to meat, especially for vegetarians and vegans.
There are two main hazards associated with sprouts – E. coli and Salmonella. Both of these terms are used a lot, but what do they really mean? What are they and where do they come from?
“Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and actually are an important part of a healthy human intestinal tract. However, some E. coli are pathogenic, meaning they can cause illness, either diarrhea or illness outside of the intestinal tract. The types of E. coli that can cause diarrhea can be transmitted through contaminated water or food, or through contact with animals or persons.”
“Salmonella is an enteric bacterium, which means that it lives in the intestinal tracts of humans and other animals, including birds. Salmonella bacteria are usually transmitted to humans by eating foods contaminated with animal feces or foods that have been handled by infected food service workers who have practiced poor personal hygiene.”
How to be safe
The best and surest method of reducing the risk of sprout seeds carrying bacteria is making sure the seeds are never contaminated. This starts with an ethical grower using good agricultural practices and organic standards. The next step is conducting rigorous testing, both in-house and independently.
Mung Bean Sprouts
Sprouts seed testing
The testing done on our sprout seeds is different than any other testing protocols for food. There is no acceptable “percentage of contamination”, as is often the case with other foods. If any bacterial contamination is detected, testing is stopped and the entire lot is rejected – sometimes 40,000 pounds or more.
To ensure the sprouting seeds we offer are as safe as possible, our supplier extensively tests both the sprouting water and the seeds to verify if any bacteria is detectable after harvest. Our supplier and an independent lab both do multiple tests to safeguard our health safety.
Current pathogen tests are considered to be 97% accurate in detecting contamination. Duplicate testing at both 48 and 96 hours brings the accuracy and confidence up to 99.91% each time, for a final accuracy of 99. 999919%!
As of early 2017, our supplier is the only company doing these extensive screening and testing protocols. The FDA is studying this protocol and has begun advocating its adoption by sprout companies for testing.
Initial Sprouts Screening Results
Screening includes inspecting the bags for any urine or feces contamination, any holes in the bags, insect larva or other contamination. Afterwards, the seed is carefully inspected with both a magnifying glass and microscope.
Each and every bag is screened – this particular lot had 860 bags, each one weighing 50 lbs. for a total of 43,000 lbs.
In-House Lab Spent Irrigation Water Contamination Test
A small sample of seed is taken from each bag and added to the overall lot sample. The entire sample is sprouted for 48 hours, increasing any potential bacteria level approximately 1,000,000 times over the starting amount, substantially increasing the probability of detection.
Next, the sprout runoff water is sampled and tested by the in-house lab. This is called “spent irrigation water”. A sample of the sprouts is crushed and tested for contamination also. These tests are done in accordance with government food safety and industry accepted protocols.
The lab tests for both Salmonella and E. coli 0157:H7 after 48 hours and again after 96 hours of culturing the irrigation water.
Both bacteria do most of their growth in the first 2 days or 48 hours. This is when the first test is performed, with the second test at 4 days or 96 hours. The second test catches any late developments that might be missed on the first.
Independent Lab Spent Irrigation Water Contamination Test
A separate, larger sample of spent irrigation water is sent to an independent lab for more extensive testing. The independent lab performs a more in-depth analysis on a wider range of pathogens than the in-house lab because of their higher level of equipment.
Notice that the independent lab tests for the top seven strains of E. coli, where the in-house lab tests for the most common one. The lab uses a food microbiology genetic detection system.
This is possible because the specific genes or DNA of the different strains of E. coli have been mapped, so they are specifically targeted during this testing. This gives better accuracy, repeatability, and confidence in the testing than any previous methods.
Independent Lab Sprouting Test
Next, the independent lab tests four pounds of randomly obtained sprouting seed from the shipment. Having an independent, third-party lab analyze the sprouting seeds gives an additional measure of confidence.
Storage Confirmation
Finally, the storage facility is inspected and documented. This ensures the cleanliness and food safety of how the seed is stored to avoid insect or rodent infestation or damage.
Homegrown sprout safety
In a home environment with only one person in contact with the sprouting seeds, cleanliness and food safety is much easier. Here are a few tips for sprouting safely:
Wash your hands thoroughly before handling seeds or sprouts, and use clean glass jars and screens that are washed with soap and hot water just before starting the sprouting process.
Rinse the sprouts well at least twice a day and tip the jar so excess water can drain, avoiding puddles where bacteria can grow.
Rinse the seeds well before starting the initial soaking period.
Now you know the steps taken to ensure the highest quality sprouting seeds are available so you can enjoy the taste and nutrition of sprouts with peace of mind.
Spring onions have been grown for a long time – Egyptians grew them along the Nile during the time of the Pharaohs. One of the easiest vegetables to grow, onions sometimes confuse home gardeners as to the best type for their garden.
Three forms of spring onions can be planted: seeds, transplants and bulbs (or sets):
Onion seeds give the greatest choice but take the longest to grow – up to 100 to 130 days from sowing the seed.
Transplants are simply young onions, like seedlings, grown to the scallion stage then bundled for sale. They grow faster but are the most expensive and fragile option as they are susceptible to transport and transplant shock.
Bulbs are small, dormant onions grown from seed the previous season. They will grow to full-sized onions in about 2 months from planting.
We recommend using onion bulbs, which can be planted without worry of frost damage and have a higher success rate than transplants. Bulbs are perfect for the home gardener as they guarantee onions for use or storage within a few weeks after planting.
As a member of the allium family they are a natural pest repellant to most foraging animals in the home garden.
Note: These details are for growing onion bulbs, not green or bunching onions. To grow green onions, simply plant the seeds and harvest when they are an appropriate size for your use!
Red Wethersfield Onions
Day Length for Spring Growing
Spring onions are usually sorted by the amount of daylight hours they need to grow bulbs; these are known as day-neutral and long day onions. Day-neutral onions form good size bulbs with 12 – 14 hours of daylight, while long-day onions need 14 – 16 hours.
The map above shows the approximate latitudes where long-day onions need to be grown. Day-neutral onions will also grow well in the more northern states in spring and summer.
Day-neutral onions are usually sweeter and juicier than their long-day counterparts. Their higher sugar and water content make them best suited for cooking and immediate use instead of storage. They are best planted from early spring to mid-summer in northern states and early spring to late fall in southern ones.
Candy is our day-neutral onion, being adapted to a wide range of day-lengths from north Texas to Maine. 12 to 14 hours of daylight will produce a good bulb. These can be grown in Zones 5 to 9.
Long-day onions are just the opposite with lower sugar and water content but higher sulphur, making them best for storage and cooking. These are planted in early spring in mid to northern states for fall harvest.
Growing long-day onions in the southern states will give small bulbs, more like scallions than full onions.
Our long-day selections include Yellow Stuttgarter (in the header photo), White Ebenezer and Red Wethersfield onions. They do best with 14 to 16 hours of daylight to form a good-sized bulb and are typically grown in colder winter areas. Zone 6 and colder is a good rule.
Spring onions prefer abundant sun and well-prepared, healthy soil with good drainage.
While onions will grow in nutrient poor soil, they won’t form good bulbs or taste as good. If possible, till in aged manure the fall before planting. Onions are heavy feeders and need constant nourishment to produce big bulbs. If needed, add a natural nitrogen source when planting, such as fish emulsion or aged compost.
Plant onions as soon as the ground can be worked in the spring, usually March or April. Make sure overnight temperatures aren’t forecast to drop below 20°F.
Plant the bulbs about an inch deep and four inches apart. Plant no more than one inch deep, otherwise bulb formation can be restricted.
Feed every few weeks with nitrogen rich fish emulsion to get good sized bulbs. Synthetic nitrogen fertilizer will grow larger bulbs at the expense of flavor. Stop fertilizing when the onion starts pushing the soil away and the bulbing process begins. Do not put the soil back around the onions; the bulb needs to emerge above the soil.
Onions have short roots and need about an inch of water per week, including rain water to avoid stress from lack of moisture. Mature bulb sizes will be smaller if they do not receive enough water. Raised beds and rows are good growing locations.
It is important to keep onion rows weed-free until they become well established. Mulching helps protect them from weeds competing for water, as well as preventing moisture loss from sun and wind.
Stuttgarter Onions
Harvesting Your Onions
Spring onions are ready for harvest when the bulb has grown large and the green tops begins to brown and fall off. The plant should be pulled at this point, but handle them carefully as they bruise easily, and bruised onions will rot in storage.
Onions need to be cured before storing. Cure them with their tops still attached, in a dry location with good air circulation – they can hang on a fence or over the railing on a porch to cure if there is no rain in the forecast. During curing the roots will shrivel and the tops will dry back sealing the onion and protect it from rot. After 7 – 10 days clip the tops and roots with shears, then store them in a cool, dry environment or use for cooking.
With a little experimenting and succession planting, you will find it easy enough to grow most of your own onions throughout the year. After tasting home-grown onions, you won’t want “store-bought” anymore!
https://underwoodgardens.com/wp-content/uploads/2017/03/Ebenezer-Onions.jpg478850Stephen Scotthttps://underwoodgardens.com/wp-content/uploads/2019/06/Survey-Header.jpgStephen Scott2017-03-03 17:10:512024-06-23 15:37:00Spring Onions – When and How to Plant
Salsify, also known as Oyster plant or vegetable oyster, was popular with the ancient Greeks who called it “the billy goat’s beard” for the silky filaments adorning the seed. The Romans increased it’s status, depicting it in frescoes in Pompeii. The famous Roman gourmet Apicius developed several recipes dedicated to Salsify and Pliny the Elder mentions it several times in his writings.
Europeans know the more common and darker scorzonera, meaning “black bark” in Italian. Salsify is regaining popularity with market and home gardeners for the delicately tasty roots and chicory flavored leaves.
Salsify Plant
This cold hardy biennial herb has a moderately thick taproot covered by a light brown skin. It has a purple flower, distinguishing itself from scorzonera by its black root and yellow flowers.
Edible Parts of the Plant
Salsify Root
The entire plant is edible when young and the root is eaten after maturing.
The Salsify root stores its carbohydrates as inulin instead of starch, which turns to fructose instead of glucose during digestion. This is ideal for diabetics as it reduces their glucose load. Most enjoy the flavor of the cooked roots over the raw.
Salsify Seedhead
Planting Seeds
Seeds are direct sown in early March to April then harvested in October. The slender, grass-like leaves normally grow to about 3 feet tall and one purple petalled flower per stalk. As the seeds mature, the flower heads turn into fluffy white puff-balls like dandelion heads and scatter on the wind.
Young Salsify Root
The root is ready for harvest in the fall when the leaves begin to die back. Flavor improves after a few frosts. Dig the roots out whole with a garden spade or fork to avoid breaking them. Only dig what you need at one time, because the roots are best fresh. Salsify will overwinter, tolerating hard frosts and even freezes.
Stephen was invited to provide an article on seed quality for Acres USA’s January 2017 issue that focuses on seeds. This is the article that was published in that issue.
Better Seed for Everyone
Everyone wants higher quality seed – from the seed company, seed grower, breeder and home gardener to the production grower. Even people who do not garden or grow anything want better seed, though they may not realize it.
Education and quality seed is the focus of our company – Terroir Seeds. We make constant efforts to continue learning and educating our customers about how seeds get from the packet to their garden. We recently had the opportunity to visit several cutting-edge seed testing laboratories and the USDA National Center for Genetic Resources Preservation to learn even more about seed testing and preservation. We want to share an insider’s look into a side of the seed world that the average person may not know exists.
Let’s look at this need for higher quality seed from a different perspective.
Everyone is a participant in what can be called the “seed economy”. Everyone, that is, who eats or wears clothes!
Anyone who eats depends on seed of some sort for their daily food – from fruits and vegetables to grains, beans, rice and grasses for dairy and meat production. Seed is intimately tied into all these foods and their continued production. Without a continued, dedicated supply of consistently high quality seed there would be catastrophic consequences to our food supply.
Cotton, cotton blends, wool, linen, hemp and silk fabrics all come from seed. Cotton comes from a cotton seed, wool from a sheep eating grass and forage from seed, linen from plant stalks grown from seed, hemp from seed and silk from silkworms eating leaves that originated as a seed.
Even those who grow and cook nothing need better seed! They still eat and wear clothes.
Pepper with Purpose
Chile de Agua for sale at market
The Chile de Agua pepper from Oaxaca, Mexico is a prime example of how seed preservation works. A well-known chef specializing in the unique Mexican cuisine of Oaxaca needed this particular chile for several new dishes. This chile wasn’t available in the US, so we were contacted through friends to work on sourcing the seed.
We found two sources in the US of supposedly authentic Chile de Agua seed and another in Oaxaca, Mexico. After the Oaxacan seed arrived, and those from Seed Saver’s Exchange network and the USDA GRIN station in Griffin, GA we sent them to our grower for trials and observation. All three seed varieties were planted in isolation to prevent cross pollination.
Authentic Chile de Agua has unique visual characteristics, the most obvious being it grows upright or erect on the plants, not hanging down or pendant. Both seed samples from the US were pendant with an incorrect shape. Only the Oaxacan seed from Mexico was correct. We then pulled all the incorrect plants, keeping only the seed from the correct and proper chiles.
The next 3 seasons were spent replanting all the harvested seed from the year prior to build up our seed stock and grow a commercial amount sufficient to sell. This process took a total of four years to complete.
Creating High-Quality Seed
There are two major approaches to improving seed quality – seed testing and seed preservation. One verifies the current condition of the seed, while the other works to preserve previous generations for future study and use.
There are several different methods of seed testing, from genetic verification and identifying DNA variations to diseases to the more traditional germination and vigor testing.
Likewise, approaches to preserving the genetic resources of seed are varied – from a simple cool room to climate and humidity controls for extended storage to cryogenic freezing with liquid nitrogen.
Seed Testing
At its most basic, testing of seed simply verifies the seed’s characteristics right now. Whether testing for germination, vigor, disease screening, genetic markers or seed health, the results show what is present or absent today. Changing trends in important characteristics are identified by comparing with previous results.
Seed germination testing
This trend analysis is a perfect example of seed testing and preservation working together, as previous generations of seed can be pulled for further testing or grown out and bred to restore lost traits.
Modern seed testing labs perform a staggering array of tests and verifications on seed samples.
Germination, vigor and physical purity are the standard seed tests for agricultural crops, flowers, herbs and grasses.
These three tests are critical for determining a seed’s performance in the field, and satisfy the US seed labeling law showing germination, physical purity and noxious weed percentages.
Seed health testing screens for seed-borne pathogens like bacteria, fungi, viruses and destructive nematodes. Seed for commercial agriculture and home gardens are often grown in foreign countries and shipped into the US, and vice versa. Seed health testing verifies the incoming or outgoing seed is free of pathogens that could wreak havoc.
Seed vigor test
Plant breeders use the healthiest seed stock possible that is free of any pathogens which would compromise breeding efforts. Agricultural researchers use tested pathogen-free seed to avoid skewing results or giving false indications from unforeseen disease interactions.
Hybrid seeds need to be tested for genetic purity, confirming their trueness to type and that the hybrid crossing is present in the majority of the seed sample. Traditional open pollinated breeders will use genetic purity testing to confirm there is no inadvertent mixing of genetic variations, verifying the purity of the parental lines.
It is common to test heirloom corn for GMO contamination – called adventitious presence testing. This test identifies any unwanted biotech traits in seed or grain lots. This is an extremely sensitive DNA based test, capable of detecting very low levels of unwanted traits in a sample – down to hundredths of a percent. This relatively expensive test demonstrates the absence of GMO contamination, an important quality aspect in the heirloom seed market.
Genetic fingerprinting, also called genotyping, identifies the genetic make-up of the seed genome, or full DNA sequence. Testing with two unique types of DNA markers gives more precision and information about the genetic diversity, relatedness and variability of the seed stock.
Computer graph of DNA testing
Fingerprinting verifies the seed variety and quality, while identifying desirable traits for seed breeders. This testing identifies 95% of the recurrent parent genetic makeup in only two generations of growing instead of five to seven with classic breeding, saving time and effort in grow-outs to verify the seed breeding. Genotyping also accelerates the discovery of superior traits by their unique markers in potential parent breeding seed stock.
Using established open pollinated seed breeding techniques, genetically fingerprinted parents help produce the desirable traits faster and with less guessing.
To be clear, these are not genetically modified organisms – GMOs – they are traditionally bred by transferring pollen from one parent to the flower of another, just as breeders have done for centuries. No foreign DNA is introduced – a tomato is bred to another tomato, or a pepper to another pepper.
The difference is how the breeding is verified, both before and after the exchange of pollen from one plant to another. The genetic markers identify positive traits that can be crossed and stabilized, and those markers show up after the cross and initial grow-outs to verify if the cross was successful. If it was successful, the grow-outs continue to stabilize and further refine the desired characteristics through selection and further testing. If it wasn’t successful, the seed breeder can try again without spending several years in grow-outs before being able to determine the breeding didn’t work like expected.
Seed Preservation
There are several different types of seed preservation, just as with seed testing. The foundational level is the home gardener, grower or gardening club selecting the best performing, best tasting open pollinated varieties to save seed from. Replanting these carefully selected seeds year upon year results in hyper-local adaptations to the micro-climates of soil, fertility, water, pH and multiple other conditions.
Seed preservation work also happens with online gardening or seed exchange forums, regional and national level seed exchanges such as Seed Saver’s Exchange and governmental efforts with the USDA.
Many countries around the world have their own dedicated seed and genetic material preservation networks, such as Russia’s N.I.Vavilov Research Institute of Plant Industry. It is named for Nikolai Vavilov, a prominent Russian botanist and geneticist credited with identifying the genetic centers of origin for many of our cultivated food plants.
The Millennium Seed Bank Partnership is coordinated by the Kew Royal Botanic Garden near London, England and is the largest seed bank in the world, storing billions of seed samples and conduct research on different species. Australia has the PlantBank, a seed bank and research institute in Mount Annan, New South Wales, Australia.
The Svalbard Global Seed Vault on the Norwegian island of Spitzbergen is a non-governmental approach with donations from several countries and organizations. AVRDC – the World Vegetable Center in Taiwan has almost 60,000 seed samples from over 150 countries and focuses on food production throughout Asia, Africa and Central America. The International Center for Tropical Agriculture (ICIAT) in Colombia focuses on improving agriculture for small farmers, with 65,000 crop samples. Navdanya in Northern India has about 5,000 crop varieties of staples like rice, wheat, millet, kidney beans and medicinal plants native to India. They have established 111 seed banks in 17 Indian states.
It has been estimated there are about 6 million seed samples stored in about 1,300 seed banks throughout the world.
Seed banks aren’t the only ways to preserve a seed. Botanical gardens could be called “living seed banks” where live plants and seeds are planted, studied, documented and preserved for future enjoyment and knowledge. Botanical gardens range from established and well-supported large city gardens to specialized and smaller scale efforts to preserve a single species or group of plants.
100 year old Native American corn in herbarium
An herbarium is another form of seed bank with a single purpose of documenting how a plant looked at a specific location at a specific time. Herbaria are like plant and seed archeological libraries with collections of dried, pressed and carefully preserved plant specimens mounted and systematically cataloged for future reference.
An herbarium can show what corn grown by the Hopi tribe a century ago looked like, or how large the seeds and leaves of amaranth were 50 years ago. Different herbaria focus on certain aspects such as regional native plants or traditional foods grown by native peoples during a specific time.
50 year old Amaranth in herbarium
The USDA plays two important roles in seed preservation that is little understood outside those in the seed industry.
The first is the Germplasm Resources Information Network or GRIN for short. It is also known as the National Plant Germplasm System. This collaborative system works to safeguard the genetic diversity of agriculturally important plants. Congress funds the program but it partners with both public and private participants. Many of the seed banks are on state university campuses with private sector breeders and researchers using the available seed resources.
USDA National Center for Genetic Resources Preservation cold vault
There are 30 collection sites that maintain specific seed stock and conduct research on them. Some are dedicated to a single crop like the Maize Genetic Stock center in Urbana, IL which collects, maintains, distributes and studies the genetics of corn. Potatoes are maintained and studied in Sturgeon Bay, WI and rice is kept in Stuttgart, AR. Others maintain regional varieties like the UC Davis location that focuses on tree fruit and nut crops along with grapes that are agriculturally important in the central valley of California.
The second role is the USDA National Center for Genetic Resources Preservation (NCGRP) in Fort Collins, CO. This is the “back-stop” for the GRIN system as well as other private, public institutions and government programs around the world. They store the foundational collections of all the GRIN locations while also working with organizations such as the International Maize and Wheat Improvement Center in Mexico, the International Rice Research Institute in the Philippines and the International Plant Genetic Resources Institute in Rome.
Founded in 1958, the NCGRP maintains, monitors and distributes seed and genetic material samples from their long-term backup storage. After receiving seed samples, they test, clean and condition the seed for the proper long-term storage environment.
USDA NCGRP’s liquid nitrogen vault
Two long-term storage methods are used. One is a traditional low temperature/low humidity storage and the other is liquid nitrogen storage. The traditional storage is kept at 0°F and 23% relative humidity. Seeds are kept in heat sealed, moisture proof foil laminated bags.
Before seeds are stored in liquid nitrogen a sample is given a liquid nitrogen test to ensure the extreme cold won’t damage the seeds. The sample is exposed to liquid nitrogen for 24 hours, then germinated after coming back to room temperature and evaluated for any germination issues.
If the test results are normal the seeds are stored in clear polyolefin plastic tubes that are barcoded and sealed. The filled tubes are arranged in metal boxes, labeled and stored in liquid nitrogen tanks.
USDA NCGRP’s liquid nitrogen vault sample straw
The vault housing both storage areas is completely self-contained and separate from the adjoining buildings. It has its own backup generator, can withstand up to 16 feet of flooding, tornadoes and the impact of a 2,500-pound object moving at 125 miles per hour. It also has a full suite of electronic security.
Outcome
If these approaches and techniques seem extravagant, it is with good reason. Our food availability and security increasingly relies on intensive production of fewer variety of crops that are very similar genetically. Along with increased production is increased vulnerability on a larger scale to pests, diseases and other stresses.
By collecting, preserving, testing, studying and distributing seeds and genetic materials immediate food system challenges can be met along with solutions and adaptations for future needs. Changes in growing conditions due to population growth, weather variability, transitions in land use and economic development all make the need for quality seed more important.
All the players in the seed economy support and advance the knowledge and quality of our seed used today. Just as the home gardeners and garden clubs preserve local seed varieties, seed companies are a “back-stop” for them. Seed banks and research facilities back up the seed companies and provide material for seed research.
https://underwoodgardens.com/wp-content/uploads/2017/01/USDA-Cold-Vault.jpg478850Stephen Scotthttps://underwoodgardens.com/wp-content/uploads/2019/06/Survey-Header.jpgStephen Scott2017-01-12 17:04:442024-04-30 17:34:00Seed Testing and Preservation: A Behind the Scenes Look at Seed Testing Labs and the USDA
Which cover crop mix is best for me?
Soil Builder vs Garden Cover Up Mix – which is best for your garden?
Both of our cover crop mixes give you multiple benefits in the soil and above it. You can’t go wrong with either one. The Garden Cover Up mix is a general use cover crop, while the Soil Builder mix is more specific toward improving the overall condition of your soil.
Cover crops improve soil in a number of ways. They protect against erosion while increasing organic matter and catch nutrients before they can leach out of the soil. Legumes add nitrogen to the soil. Their roots help unlock nutrients, converting them to more available forms. Cover crops provide habitat or food source for important soil organisms, break up compacted soil layers, help dry out wet soils and maintain soil moisture in arid climates.
Let’s look at how cover crops work overall, then we’ll see the differences of each mix.
Most cover crop mixes are legumes and grains or grasses. Each one has a different benefit to the soil. Legumes include alfalfa, clover, peas, beans, lentils, soybeans and peanuts. Well-known grains are wheat, rye, barley and oats which are used as grasses for animal forage.
Crimson Clover
Legumes
Legumes help reduce or prevent erosion, produce biomass, suppress weeds and add organic matter to the soil. They also attract beneficial insects, but are most well-known for fixing nitrogen from the air into the soil in a plant-friendly form. They are generally lower in carbon and higher in nitrogen than grasses, so they break down faster releasing their nutrients sooner. Weed control may not last as long as an equivalent amount of grass residue. Legumes do not increase soil organic matter as much as grains or grasses. Their ground cover makes for good weed control, as well as benefiting other cover crops.
Rye Cover Crop
Grains or grasses
Grain or grass cover crops help retain nutrients–especially nitrogen–left over from a previous crop, reduce or prevent erosion and suppress weeds. They produce large amounts of mulch residue and add organic matter above and below the soil, reducing erosion and suppressing weeds. They are higher in carbon than legumes, breaking down slower resulting in longer-lasting mulch residue. This releases the nutrients over a longer time, complementing the faster-acting release of the legumes.
This pretty well describes what our Garden Cover Up mix does, as it is made up of 70% legumes and 30% grasses.
Our Soil Builder mix takes this approach a couple of steps further in the soil improvement direction with the addition of several varieties known for their benefits to the soil structure, micro-organisms or overall fertility.
For example, the mung bean is a legume used for nitrogen fixation and improving the mycorrhizal populations, which increase the amount of nutrients available to each plant through its roots.
Spring Sunflower
Sunflowers are renowned for their prolific root systems and ability to soak up residual nutrients out of reach for other commonly used covers or crops. The bright colors attract pollinators and beneficials such as bees, damsel bugs, lacewings, hoverflies, minute pirate bugs, and non-stinging parasitic wasps.
Safflower has an exceptionally deep taproot reaching down 8-10 feet, breaking up hard pans, encouraging water and air movement into the soil and scavenging nutrients from depths unreachable to most crops. It does all of this while being resistant to all root lesion nematodes. Gardeners growing safflower usually see low pest pressure and an increase in beneficials such as spiders, ladybugs and lacewings.
Now you see why you can’t go wrong in choosing one of our cover crop mixes! Both greatly increase the health and fertility of the soil, along with above-ground improvements in a short time. Even if you only have a month, the Garden Cover Up mix will impress you for the next planting season.
For a general approach with soils that need a boost but are still producing well, the Garden Cover Up mix is the best choice. Our Soil Builder mix is for rejuvenating a dormant bed or giving some intensive care to a soil that has struggled lately. Both will give you a serious head start in establishing a new growing area, whether it is for trees, shrubs, flowers, herbs or vegetables.
Grow Lettuce in Summer
Grow Your Lettuce Longer in Warm Weather
With a little knowledge and a tiny bit of preparation, you can grow lettuce throughout the summer without bolting. Imagine serving your own fresh-harvested, garden-grown lettuce throughout the summer!
First, some knowledge
Lettuce is a cool-season vegetable, meaning it grows best in temperatures around 60 – 65°F. Once temperatures rise above 80°F, lettuce will normally start to “bolt” or stop leaf production and send up a stalk to flower and produce seed. The leaves become bitter at this stage.
This is because the mainstay of our beloved salads is not a North American native, but an ancient part of our dinner table. Belonging to the daisy family, lettuce was first grown by Egyptians around 4,700 years ago. They cultivated lettuce from a weed used only for its oil-rich seeds to a valued food with succulent leaves that nourished both the mind and libido. Images in tombs of lettuce being used in religious ceremonies show its prominent place in Egyptian culture.
The earliest domesticated form resembled a large head of Romaine lettuce, which was passed to the Greeks and then the Romans. Around 50 AD, Roman agriculturalist Columella described several lettuce cultivars, some of which are recognizable as ancestors to our current favorites. Even today, Romaine types and loose-leaf lettuces tolerate heat better than tighter heading lettuces like Iceberg.
Three factors to growing lettuce in summer
The temperatures you are concerned about are both air and soil, as a lettuce plant (or any garden plant for that matter) tolerates a higher air temperature if the soil around its roots is cool and moist. Ensuring a cool and damp soil gives you more air temperature leeway. Because lettuce has wide and shallow roots, a drip system on a timer teamed up with a thick mulch keeps it happier in warm weather.
Shade is the third part to keeping lettuce growing vigorously later into warm weather. Reducing sun exposure lowers the heat to the leaves, but also to the soil and roots – creating a combined benefit. Deep shade isn’t good, but a systemallowing sun during the morning while sheltering the plants in the afternoon keeps your salad machines going much longer than you thought possible.
One last bit of knowledge. Most lettuce seeds become dormant (won’t germinate) as temperatures rise above 80°F, a condition called”thermo-inhibition”. This trait is a carryover from wild lettuce in the Mediterranean Middle East, where summers are hot with little moisture. If the lettuce seeds sprouted under these conditions, they would soon die out and the species would go extinct.
Thanks to research, there are some easy techniques to germinate lettuce seeds in warm weather – our article Improve Lettuce Seed Germination shows you how. Now you’ll be able to start lettuce when no one else can!
Here’s how to grow lettuce in summer
The three most effective elements in keeping your lettuce producing during warm weather are a drip system on a timer, a good bed of mulch and shade. Let’s look at each one and how they help.
Lettuce growing with mulch, shade & drip system
A drip system on a timer maintains moisture levels much more evenly than hand watering, and the timer can be set for how much and how often water is needed. Checking the soil moisture levels is easy – just push your finger into the soil up to the second knuckle. If the soil feels moist and spongy the moisture is perfect for lettuce. Adjust the number and length of watering each time up or down to maintain this level. From experience, we usually start the timer once a day for 10 minutes in the spring and go to 2 and sometimes 3 times a day for 10 minutes during the heat of the summer. As the weather cools down, we decrease the amount of water accordingly.
A thick bed of mulch reduces moisture loss at the surface of the soil from heat and breezes. Here in central Arizona, it’s not uncommon to have a 15-mph breeze with 90°F+ with 5 – 10% humidity levels. Basically, we garden in a giant hair-dryer!
We use two inches of wood chip mulch, but straw also works well and some gardeners have good success with well-aged compost. With mulch, the soil moisture levels are at the top of the soil where it meets the mulch. Without it, the moisture doesn’t appear until you’ve dug down at least two inches, with three inches having the same amount of moisture as the surface does with mulch. Another benefit of wood chip mulch is it provides needed nutrients to the soil and encourages earthworms and other beneficial soil life as it decomposes. The beds where we’ve put wood chips down have three times the amount of earthworm activity as those that have only compost or nothing at all.
The third element is shade, which might seem daunting but is surprisingly simple to provide. Shade can be from various sources – a living trellis of cucamelon, vine peach or Malabar spinach; a row of tall sunflowers on thewest side of the bed; a container garden on the east side of the house or garage to capture afternoon shade, or a shade cloth structure on the west side of the bed or over a container or raised bed. Trees can also give partial shade – grow on the east side to take advantage of shade during the hotter, more stressful afternoons.
Real world examples
Here are two examples showing that it does:
The first example is a study conducted by Kansas City area growers in cooperation with Kansas State University and the Organic Farming Research Foundation.
The second example is a two-season grow-out test by the Sacramento County Master Gardeners at their Fair Oaks Horticulture Center during the summers of 2015 and 2016.
Easy shade for your garden beds
Here’s a quick and easy way to shade any container, raised bed or row in your garden:
Simple lettuce shade structure
Use 1/2 inch PVC pipe from any hardware store. 1/2 inch is the least expensive and easiest to work with for this use.
Shade structure detail
Using PVC elbows, simply insert the tubing into the elbow and push the uprights into the soil at the edge of the planter or raised bed. No glue needed, so they can be taken down and re-used next season.
Planter with shade system
We used some leftover shade cloth from another project and cable ties to secure the shade cloth to the PVC tubing.
Shade cloth canopy
The front of the shade canopy is left loose so we can harvest easily.
Lettuce shade detail
The right half of the lettuce is shaded, with the left half getting shade as the day progresses.
Now you have the tools and knowledge, so plan on successfully growing lettuce after everyone else has given up this season! As your accomplishments are recognized and compliments roll your way – make sure to share your tools and spread the success.
Update – Three Weeks Later
Lettuce after 3 weeks of heat
Our lettuce looks amazing, considering we’ve had continuous temperatures above 95°F for the past 13 days and above 100°F for the past 9 days. The Sweet & Spicy Mix hasn’t slowed down and is robust, crunchy, and still sweet with no bitter flavors. The growth is easy to see, comparing to the above photos.
Lettuce after 3 weeks of heat – detail of leaves
Looking closer, it isn’t perfect. There are some small holes and some of the leaf edges are a little toasty, but these conditions are so far outside of lettuce comfort zone, it’s like growing on Mars!
References
Homegrown Sprouts Safety
Are homegrown sprouts safe?
We’ve greatly enjoyed our own homegrown sprouts for the past several years. There’s just something about their fresh taste and crispy crunch that can be enjoyed any time of year, no matter the weather.
As with all our seeds, we make sure we know who our growers are and where our seeds come from. This is even more important with seeds used for sprouting as they are eaten directly as a food.
We chose our sprouting seeds supplier because of their commitment to the safest and healthiest seeds possible. They showed us their safety standards and testing protocols and we want to share them with you.
Growing your own sprouts at home is much safer than buying them off the shelf at a supermarket, and we’ll show you why.
Sprouts are healthy, nutritious and are rich in vitamins, minerals, proteins, enzymes, bioflavonoids, antioxidants, phytoestrogens, glucosinolates and other phytochemicals. They are an excellent alternative to meat, especially for vegetarians and vegans.
Fresh Homegrown Sprouts
Hazards of sprouts
There are two main hazards associated with sprouts – E. coli and Salmonella. Both of these terms are used a lot, but what do they really mean? What are they and where do they come from?
From the CDC website:
“Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and actually are an important part of a healthy human intestinal tract. However, some E. coli are pathogenic, meaning they can cause illness, either diarrhea or illness outside of the intestinal tract. The types of E. coli that can cause diarrhea can be transmitted through contaminated water or food, or through contact with animals or persons.”
From the USDA website:
“Salmonella is an enteric bacterium, which means that it lives in the intestinal tracts of humans and other animals, including birds. Salmonella bacteria are usually transmitted to humans by eating foods contaminated with animal feces or foods that have been handled by infected food service workers who have practiced poor personal hygiene.”
How to be safe
The best and surest method of reducing the risk of sprout seeds carrying bacteria is making sure the seeds are never contaminated. This starts with an ethical grower using good agricultural practices and organic standards. The next step is conducting rigorous testing, both in-house and independently.
Mung Bean Sprouts
Sprouts seed testing
The testing done on our sprout seeds is different than any other testing protocols for food. There is no acceptable “percentage of contamination”, as is often the case with other foods. If any bacterial contamination is detected, testing is stopped and the entire lot is rejected – sometimes 40,000 pounds or more.
To ensure the sprouting seeds we offer are as safe as possible, our supplier extensively tests both the sprouting water and the seeds to verify if any bacteria is detectable after harvest. Our supplier and an independent lab both do multiple tests to safeguard our health safety.
As of early 2017, our supplier is the only company doing these extensive screening and testing protocols. The FDA is studying this protocol and has begun advocating its adoption by sprout companies for testing.
Initial Sprouts Screening Results
Screening includes inspecting the bags for any urine or feces contamination, any holes in the bags, insect larva or other contamination. Afterwards, the seed is carefully inspected with both a magnifying glass and microscope.
Each and every bag is screened – this particular lot had 860 bags, each one weighing 50 lbs. for a total of 43,000 lbs.
In-House Lab Spent Irrigation Water Contamination Test
A small sample of seed is taken from each bag and added to the overall lot sample. The entire sample is sprouted for 48 hours, increasing any potential bacteria level approximately 1,000,000 times over the starting amount, substantially increasing the probability of detection.
Next, the sprout runoff water is sampled and tested by the in-house lab. This is called “spent irrigation water”. A sample of the sprouts is crushed and tested for contamination also. These tests are done in accordance with government food safety and industry accepted protocols.
The lab tests for both Salmonella and E. coli 0157:H7 after 48 hours and again after 96 hours of culturing the irrigation water.
Both bacteria do most of their growth in the first 2 days or 48 hours. This is when the first test is performed, with the second test at 4 days or 96 hours. The second test catches any late developments that might be missed on the first.
Independent Lab Spent Irrigation Water Contamination Test
A separate, larger sample of spent irrigation water is sent to an independent lab for more extensive testing. The independent lab performs a more in-depth analysis on a wider range of pathogens than the in-house lab because of their higher level of equipment.
Notice that the independent lab tests for the top seven strains of E. coli, where the in-house lab tests for the most common one. The lab uses a food microbiology genetic detection system.
This is possible because the specific genes or DNA of the different strains of E. coli have been mapped, so they are specifically targeted during this testing. This gives better accuracy, repeatability, and confidence in the testing than any previous methods.
Independent Lab Sprouting Test
Next, the independent lab tests four pounds of randomly obtained sprouting seed from the shipment. Having an independent, third-party lab analyze the sprouting seeds gives an additional measure of confidence.
Storage Confirmation
Finally, the storage facility is inspected and documented. This ensures the cleanliness and food safety of how the seed is stored to avoid insect or rodent infestation or damage.
Homegrown sprout safety
In a home environment with only one person in contact with the sprouting seeds, cleanliness and food safety is much easier. Here are a few tips for sprouting safely:
Now you know the steps taken to ensure the highest quality sprouting seeds are available so you can enjoy the taste and nutrition of sprouts with peace of mind.
Spring Onions – When and How to Plant
Great Onions in Spring
Spring onions have been grown for a long time – Egyptians grew them along the Nile during the time of the Pharaohs. One of the easiest vegetables to grow, onions sometimes confuse home gardeners as to the best type for their garden.
Three forms of spring onions can be planted: seeds, transplants and bulbs (or sets):
We recommend using onion bulbs, which can be planted without worry of frost damage and have a higher success rate than transplants. Bulbs are perfect for the home gardener as they guarantee onions for use or storage within a few weeks after planting.
As a member of the allium family they are a natural pest repellant to most foraging animals in the home garden.
Red Wethersfield Onions
Day Length for Spring Growing
Spring onions are usually sorted by the amount of daylight hours they need to grow bulbs; these are known as day-neutral and long day onions. Day-neutral onions form good size bulbs with 12 – 14 hours of daylight, while long-day onions need 14 – 16 hours.
The map above shows the approximate latitudes where long-day onions need to be grown. Day-neutral onions will also grow well in the more northern states in spring and summer.
Day-neutral onions are usually sweeter and juicier than their long-day counterparts. Their higher sugar and water content make them best suited for cooking and immediate use instead of storage. They are best planted from early spring to mid-summer in northern states and early spring to late fall in southern ones.
Candy is our day-neutral onion, being adapted to a wide range of day-lengths from north Texas to Maine. 12 to 14 hours of daylight will produce a good bulb. These can be grown in Zones 5 to 9.
Long-day onions are just the opposite with lower sugar and water content but higher sulphur, making them best for storage and cooking. These are planted in early spring in mid to northern states for fall harvest.
Our long-day selections include Yellow Stuttgarter (in the header photo), White Ebenezer and Red Wethersfield onions. They do best with 14 to 16 hours of daylight to form a good-sized bulb and are typically grown in colder winter areas. Zone 6 and colder is a good rule.
Sweet Candy Onions
Planting and Growing Spring Onions
Spring onions prefer abundant sun and well-prepared, healthy soil with good drainage.
While onions will grow in nutrient poor soil, they won’t form good bulbs or taste as good. If possible, till in aged manure the fall before planting. Onions are heavy feeders and need constant nourishment to produce big bulbs. If needed, add a natural nitrogen source when planting, such as fish emulsion or aged compost.
Feed every few weeks with nitrogen rich fish emulsion to get good sized bulbs. Synthetic nitrogen fertilizer will grow larger bulbs at the expense of flavor. Stop fertilizing when the onion starts pushing the soil away and the bulbing process begins. Do not put the soil back around the onions; the bulb needs to emerge above the soil.
Onions have short roots and need about an inch of water per week, including rain water to avoid stress from lack of moisture. Mature bulb sizes will be smaller if they do not receive enough water. Raised beds and rows are good growing locations.
It is important to keep onion rows weed-free until they become well established. Mulching helps protect them from weeds competing for water, as well as preventing moisture loss from sun and wind.
Stuttgarter Onions
Harvesting Your Onions
Spring onions are ready for harvest when the bulb has grown large and the green tops begins to brown and fall off. The plant should be pulled at this point, but handle them carefully as they bruise easily, and bruised onions will rot in storage.
Onions need to be cured before storing. Cure them with their tops still attached, in a dry location with good air circulation – they can hang on a fence or over the railing on a porch to cure if there is no rain in the forecast. During curing the roots will shrivel and the tops will dry back sealing the onion and protect it from rot. After 7 – 10 days clip the tops and roots with shears, then store them in a cool, dry environment or use for cooking.
With a little experimenting and succession planting, you will find it easy enough to grow most of your own onions throughout the year. After tasting home-grown onions, you won’t want “store-bought” anymore!
Salsify – the Vegetable Oyster
An Ancient Vegetable
Salsify, also known as Oyster plant or vegetable oyster, was popular with the ancient Greeks who called it “the billy goat’s beard” for the silky filaments adorning the seed. The Romans increased it’s status, depicting it in frescoes in Pompeii. The famous Roman gourmet Apicius developed several recipes dedicated to Salsify and Pliny the Elder mentions it several times in his writings.
Europeans know the more common and darker scorzonera, meaning “black bark” in Italian. Salsify is regaining popularity with market and home gardeners for the delicately tasty roots and chicory flavored leaves.
Salsify Plant
This cold hardy biennial herb has a moderately thick taproot covered by a light brown skin. It has a purple flower, distinguishing itself from scorzonera by its black root and yellow flowers.
Edible Parts of the Plant
Salsify Root
The entire plant is edible when young and the root is eaten after maturing.
Young roots are eaten raw in salads, or are boiled, baked, and sautéed once mature. They are added to soups or are grated and made into cakes. The flower buds and flowers are added to salads or preserved by pickling. Young flower stalks are picked, cooked, dressed and eaten like asparagus. The seeds are sprouted and eaten like alfalfa sprouts for a refreshing and unique flavor addition.
Salsify Fritter
Cooked and puréed roots coated in egg batter and flour then pan or deep-fried to a crispy golden brown make Salsify fritters.
The Salsify root stores its carbohydrates as inulin instead of starch, which turns to fructose instead of glucose during digestion. This is ideal for diabetics as it reduces their glucose load. Most enjoy the flavor of the cooked roots over the raw.
Salsify Seedhead
Planting Seeds
Seeds are direct sown in early March to April then harvested in October. The slender, grass-like leaves normally grow to about 3 feet tall and one purple petalled flower per stalk. As the seeds mature, the flower heads turn into fluffy white puff-balls like dandelion heads and scatter on the wind.
Young Salsify Root
The root is ready for harvest in the fall when the leaves begin to die back. Flavor improves after a few frosts. Dig the roots out whole with a garden spade or fork to avoid breaking them. Only dig what you need at one time, because the roots are best fresh. Salsify will overwinter, tolerating hard frosts and even freezes.
Seed Testing and Preservation: A Behind the Scenes Look at Seed Testing Labs and the USDA
Stephen was invited to provide an article on seed quality for Acres USA’s January 2017 issue that focuses on seeds. This is the article that was published in that issue.
Better Seed for Everyone
Everyone wants higher quality seed – from the seed company, seed grower, breeder and home gardener to the production grower. Even people who do not garden or grow anything want better seed, though they may not realize it.
Education and quality seed is the focus of our company – Terroir Seeds. We make constant efforts to continue learning and educating our customers about how seeds get from the packet to their garden. We recently had the opportunity to visit several cutting-edge seed testing laboratories and the USDA National Center for Genetic Resources Preservation to learn even more about seed testing and preservation. We want to share an insider’s look into a side of the seed world that the average person may not know exists.
Let’s look at this need for higher quality seed from a different perspective.
Anyone who eats depends on seed of some sort for their daily food – from fruits and vegetables to grains, beans, rice and grasses for dairy and meat production. Seed is intimately tied into all these foods and their continued production. Without a continued, dedicated supply of consistently high quality seed there would be catastrophic consequences to our food supply.
Cotton, cotton blends, wool, linen, hemp and silk fabrics all come from seed. Cotton comes from a cotton seed, wool from a sheep eating grass and forage from seed, linen from plant stalks grown from seed, hemp from seed and silk from silkworms eating leaves that originated as a seed.
Even those who grow and cook nothing need better seed! They still eat and wear clothes.
Pepper with Purpose
Chile de Agua for sale at market
The Chile de Agua pepper from Oaxaca, Mexico is a prime example of how seed preservation works. A well-known chef specializing in the unique Mexican cuisine of Oaxaca needed this particular chile for several new dishes. This chile wasn’t available in the US, so we were contacted through friends to work on sourcing the seed.
We found two sources in the US of supposedly authentic Chile de Agua seed and another in Oaxaca, Mexico. After the Oaxacan seed arrived, and those from Seed Saver’s Exchange network and the USDA GRIN station in Griffin, GA we sent them to our grower for trials and observation. All three seed varieties were planted in isolation to prevent cross pollination.
Authentic Chile de Agua has unique visual characteristics, the most obvious being it grows upright or erect on the plants, not hanging down or pendant. Both seed samples from the US were pendant with an incorrect shape. Only the Oaxacan seed from Mexico was correct. We then pulled all the incorrect plants, keeping only the seed from the correct and proper chiles.
The next 3 seasons were spent replanting all the harvested seed from the year prior to build up our seed stock and grow a commercial amount sufficient to sell. This process took a total of four years to complete.
Creating High-Quality Seed
There are two major approaches to improving seed quality – seed testing and seed preservation. One verifies the current condition of the seed, while the other works to preserve previous generations for future study and use.
There are several different methods of seed testing, from genetic verification and identifying DNA variations to diseases to the more traditional germination and vigor testing.
Likewise, approaches to preserving the genetic resources of seed are varied – from a simple cool room to climate and humidity controls for extended storage to cryogenic freezing with liquid nitrogen.
Seed Testing
At its most basic, testing of seed simply verifies the seed’s characteristics right now. Whether testing for germination, vigor, disease screening, genetic markers or seed health, the results show what is present or absent today. Changing trends in important characteristics are identified by comparing with previous results.
Seed germination testing
This trend analysis is a perfect example of seed testing and preservation working together, as previous generations of seed can be pulled for further testing or grown out and bred to restore lost traits.
Modern seed testing labs perform a staggering array of tests and verifications on seed samples.
These three tests are critical for determining a seed’s performance in the field, and satisfy the US seed labeling law showing germination, physical purity and noxious weed percentages.
Seed health testing screens for seed-borne pathogens like bacteria, fungi, viruses and destructive nematodes. Seed for commercial agriculture and home gardens are often grown in foreign countries and shipped into the US, and vice versa. Seed health testing verifies the incoming or outgoing seed is free of pathogens that could wreak havoc.
Seed vigor test
Plant breeders use the healthiest seed stock possible that is free of any pathogens which would compromise breeding efforts. Agricultural researchers use tested pathogen-free seed to avoid skewing results or giving false indications from unforeseen disease interactions.
Hybrid seeds need to be tested for genetic purity, confirming their trueness to type and that the hybrid crossing is present in the majority of the seed sample. Traditional open pollinated breeders will use genetic purity testing to confirm there is no inadvertent mixing of genetic variations, verifying the purity of the parental lines.
It is common to test heirloom corn for GMO contamination – called adventitious presence testing. This test identifies any unwanted biotech traits in seed or grain lots. This is an extremely sensitive DNA based test, capable of detecting very low levels of unwanted traits in a sample – down to hundredths of a percent. This relatively expensive test demonstrates the absence of GMO contamination, an important quality aspect in the heirloom seed market.
Genetic fingerprinting, also called genotyping, identifies the genetic make-up of the seed genome, or full DNA sequence. Testing with two unique types of DNA markers gives more precision and information about the genetic diversity, relatedness and variability of the seed stock.
Computer graph of DNA testing
Fingerprinting verifies the seed variety and quality, while identifying desirable traits for seed breeders. This testing identifies 95% of the recurrent parent genetic makeup in only two generations of growing instead of five to seven with classic breeding, saving time and effort in grow-outs to verify the seed breeding. Genotyping also accelerates the discovery of superior traits by their unique markers in potential parent breeding seed stock.
The difference is how the breeding is verified, both before and after the exchange of pollen from one plant to another. The genetic markers identify positive traits that can be crossed and stabilized, and those markers show up after the cross and initial grow-outs to verify if the cross was successful. If it was successful, the grow-outs continue to stabilize and further refine the desired characteristics through selection and further testing. If it wasn’t successful, the seed breeder can try again without spending several years in grow-outs before being able to determine the breeding didn’t work like expected.
Seed Preservation
There are several different types of seed preservation, just as with seed testing. The foundational level is the home gardener, grower or gardening club selecting the best performing, best tasting open pollinated varieties to save seed from. Replanting these carefully selected seeds year upon year results in hyper-local adaptations to the micro-climates of soil, fertility, water, pH and multiple other conditions.
Many countries around the world have their own dedicated seed and genetic material preservation networks, such as Russia’s N.I.Vavilov Research Institute of Plant Industry. It is named for Nikolai Vavilov, a prominent Russian botanist and geneticist credited with identifying the genetic centers of origin for many of our cultivated food plants.
The Millennium Seed Bank Partnership is coordinated by the Kew Royal Botanic Garden near London, England and is the largest seed bank in the world, storing billions of seed samples and conduct research on different species. Australia has the PlantBank, a seed bank and research institute in Mount Annan, New South Wales, Australia.
The Svalbard Global Seed Vault on the Norwegian island of Spitzbergen is a non-governmental approach with donations from several countries and organizations. AVRDC – the World Vegetable Center in Taiwan has almost 60,000 seed samples from over 150 countries and focuses on food production throughout Asia, Africa and Central America. The International Center for Tropical Agriculture (ICIAT) in Colombia focuses on improving agriculture for small farmers, with 65,000 crop samples. Navdanya in Northern India has about 5,000 crop varieties of staples like rice, wheat, millet, kidney beans and medicinal plants native to India. They have established 111 seed banks in 17 Indian states.
Seed banks aren’t the only ways to preserve a seed. Botanical gardens could be called “living seed banks” where live plants and seeds are planted, studied, documented and preserved for future enjoyment and knowledge. Botanical gardens range from established and well-supported large city gardens to specialized and smaller scale efforts to preserve a single species or group of plants.
100 year old Native American corn in herbarium
An herbarium is another form of seed bank with a single purpose of documenting how a plant looked at a specific location at a specific time. Herbaria are like plant and seed archeological libraries with collections of dried, pressed and carefully preserved plant specimens mounted and systematically cataloged for future reference.
An herbarium can show what corn grown by the Hopi tribe a century ago looked like, or how large the seeds and leaves of amaranth were 50 years ago. Different herbaria focus on certain aspects such as regional native plants or traditional foods grown by native peoples during a specific time.
50 year old Amaranth in herbarium
The first is the Germplasm Resources Information Network or GRIN for short. It is also known as the National Plant Germplasm System. This collaborative system works to safeguard the genetic diversity of agriculturally important plants. Congress funds the program but it partners with both public and private participants. Many of the seed banks are on state university campuses with private sector breeders and researchers using the available seed resources.
USDA National Center for Genetic Resources Preservation cold vault
There are 30 collection sites that maintain specific seed stock and conduct research on them. Some are dedicated to a single crop like the Maize Genetic Stock center in Urbana, IL which collects, maintains, distributes and studies the genetics of corn. Potatoes are maintained and studied in Sturgeon Bay, WI and rice is kept in Stuttgart, AR. Others maintain regional varieties like the UC Davis location that focuses on tree fruit and nut crops along with grapes that are agriculturally important in the central valley of California.
The second role is the USDA National Center for Genetic Resources Preservation (NCGRP) in Fort Collins, CO. This is the “back-stop” for the GRIN system as well as other private, public institutions and government programs around the world. They store the foundational collections of all the GRIN locations while also working with organizations such as the International Maize and Wheat Improvement Center in Mexico, the International Rice Research Institute in the Philippines and the International Plant Genetic Resources Institute in Rome.
Founded in 1958, the NCGRP maintains, monitors and distributes seed and genetic material samples from their long-term backup storage. After receiving seed samples, they test, clean and condition the seed for the proper long-term storage environment.
USDA NCGRP’s liquid nitrogen vault
Two long-term storage methods are used. One is a traditional low temperature/low humidity storage and the other is liquid nitrogen storage. The traditional storage is kept at 0°F and 23% relative humidity. Seeds are kept in heat sealed, moisture proof foil laminated bags.
Before seeds are stored in liquid nitrogen a sample is given a liquid nitrogen test to ensure the extreme cold won’t damage the seeds. The sample is exposed to liquid nitrogen for 24 hours, then germinated after coming back to room temperature and evaluated for any germination issues.
If the test results are normal the seeds are stored in clear polyolefin plastic tubes that are barcoded and sealed. The filled tubes are arranged in metal boxes, labeled and stored in liquid nitrogen tanks.
USDA NCGRP’s liquid nitrogen vault sample straw
The vault housing both storage areas is completely self-contained and separate from the adjoining buildings. It has its own backup generator, can withstand up to 16 feet of flooding, tornadoes and the impact of a 2,500-pound object moving at 125 miles per hour. It also has a full suite of electronic security.
Outcome
If these approaches and techniques seem extravagant, it is with good reason. Our food availability and security increasingly relies on intensive production of fewer variety of crops that are very similar genetically. Along with increased production is increased vulnerability on a larger scale to pests, diseases and other stresses.
By collecting, preserving, testing, studying and distributing seeds and genetic materials immediate food system challenges can be met along with solutions and adaptations for future needs. Changes in growing conditions due to population growth, weather variability, transitions in land use and economic development all make the need for quality seed more important.
All the players in the seed economy support and advance the knowledge and quality of our seed used today. Just as the home gardeners and garden clubs preserve local seed varieties, seed companies are a “back-stop” for them. Seed banks and research facilities back up the seed companies and provide material for seed research.