Aphids are perennial pests that gardeners deal with, often with very mixed results. We’ll show you both prevention and treatment methods for aphids.
Terra Madre is a biennial international food conference in Turin, Italy showcasing local food systems and producers from all over the world.
Aphids are one of the perennial pests that gardeners deal with, often with very mixed results. What works one year seems to fall flat on its face the next, with the reverse also being true. Aphids are tiny, soft bodied insects that have piercing, sucking mouthparts to feed on plant saps. They live in colonies, most often the underside of leaves and where the tender young growth is on a plant.
By themselves, aphids rarely outright kill a plant but they can inflict serious damage to both its flowers and fruit. It only takes a few aphids sucking on a young flower or fruit to weaken it or damage it beyond being edible. The sap they extract weakens the plant, stunting its growth and food production. The aphids can also be carriers or vectors of diseases or viruses, which they infect the plant with as they pierce the cell walls and extract the plant sap. Just a few seconds is all it takes for a virus to transfer from the mouth of an aphid to the plant.
Aphids will often arrive in a garden or on a plant by flying in. A small number will arrive and leave their wingless young who feed on the plant and immediately lay eggs, increasing the population quickly. The adults will then fly off and repeat this several times. This is why gardeners will often complain that the aphids overwhelmed the garden “overnight”. Each adult aphid can produce up to 80 offspring every week!
So what can be done about these insects? There are several methods of dealing with them, broken down into two main approaches – prevention and treatment. The prevention phase happens in the fall and early winter with soil testing and amendments that set the stage for success the next growing season. Treatment is just that – what to do when those pesky insects show up uninvited in your garden!
Let’s start at the beginning, shall we? Nitrogen is a big, big player in the aphid dance. Aphids love nitrogen, plain and simple. They are attracted to the soft growing parts of a plant that are high in nitrogen, as it is a major factor in plant growth. Aphids are also really attracted to young seedlings, since everything on a seedling is growing and there is lots of nitrogen to be had.
Nitrogen plays a very important part in a plants growth as well as the content of its sap. Soils with excessively high nitrogen create very fast growing plants. This leads to rapid cell wall growth, which are elongated, thinner and much easier for the piercing mouth-parts of an aphid to penetrate than normal. The plant sap will also be high in nitrogen and will be especially attractive for the aphid. It is very important to understand that high nitrogen sap will be lower in overall sugar content – also known as brix – because nitrogen forms amino acids and proteins – such as chlorophyll – but specifically needs magnesium, phosphorus and carbon to form sugars. This can’t happen if there is excess nitrogen, as there aren’t enough of the other elements to form those sugars. Once the soil is amended with the correct nutrients, the plant will increase the brix/sugar levels and the aphids will die from sucking high sugar content plant sap as it is deadly – aphids can’t digest the sugars with no pancreas and thus die.
What all this means is that using high doses of chemical fertilizers will encourage aphids to call your garden home! Almost all commercial fertilizers are high in nitrogen and release their nutrients much faster than compost or other soil amendments, making aphid pressures much worse than they would normally be. They also contribute to lots of flowers with little fruit production or stunted and smaller than normal sized fruit.
It is interesting to note with soybean studies at Penn State University naturally occurring nitrogen-fixing bacteria – called rhizobia – provided a better form of naturally occurring nitrogen than the laboratory bred inoculated strains did. Plants growing in the naturally occurring rhizobia soils had markedly fewer aphids and stress than the inoculated ones. The amount of nitrogen provided by the lab developed rhizobia and the naturally occurring strains were the same, with the natural rhizobia having much lower aphid populations on the plants. They are continuing the study to see why this happens.
There is a concept at work here that we need to briefly discuss so that you can understand where we are going from here. The “Law of the Minimum” shows how interrelated many nutrients and elements are to healthy plants, not just the N,P and K that are listed on fertilizer bags.
The Law of the Minimum states,
“Plant growth is determined by the scarcest, “limiting” nutrient; if even one of the many required nutrients is deficient, the plant will not grow and produce at its optimum.”
The preventative method is to have a complete, comprehensive soil analysis done by a professional lab. I’ve mentioned these before, but they bear another – Crop Services International and Texas Plant and Soil Lab are great labs. They are thorough, friendly and will give you the info you need at a reasonable price. From this analysis, you will know exactly what soil nutrients, amendments and trace minerals are needed to eliminate a high nitrogen condition in your soil and plants, and by extension reducing the population and attraction of aphids.
Another, very simple method is to stop using commercially available chemical fertilizers! Without naming names, these come in a bag and sometimes have the word “miracle” attached to them. There are a number of brands that can be bought at any garden center or big box store in their garden section. Well-aged and decomposed compost – especially if you’ve worked with it how we discuss in our articles on compost – will give you a continuous supply of “soil food” to apply to your garden twice a year, in the early spring and again in the late fall. This compost with the amendments will slowly release the nutrients that the garden needs, along with attracting the biological elements in the soil that do the real work – earthworms, pillbugs, beneficial nematodes, fungi and all sorts of other hard-working critters that seriously improve the soil on a continuous basis.
Another aspect of prevention is cultural control, or removing the suitable environments where aphids can overwinter or establish an initial population to then swarm your garden. Standing weeds can be harbors of aphids, so remove them and remove dead plants from the garden in the fall. Don’t wait until the springtime to clean up the garden, as this can provide the perfect habitat for aphid eggs to be sheltered under. Inspect trees and bushes for aphid eggs in the fall, remove them by hand, vacuum or with a strong blast of water.
Now that you’ve got the prevention and preparation covered, what can be done if and when the nasty aphids arrive? This is where the treatment portion comes in, and it would be wise to prepare for this as well. Early detection is very important for successful treatment, as if the aphids get a toe-hold, it will be much more difficult to rid your plants of several sizable populations instead of just one or two small ones. The incoming flights of adult aphids are random, so consistent inspection is best. This is very easy, just flip over the top, youngest leaves of several plants and look for the clusters of small aphids on the underside. Look around bud areas as well. If you see any aphids, they will be in small clusters or colonies and can be easily dealt with at this stage. Crush them by hand or prune the leaves or buds to remove them. Once you see the first small populations, go back and be very thorough with the rest of your plants, taking the time to examine them well. Trust me on this, the time spent now will save you much heartache, back ache, time and frustration in the very near future!
Aphids will excrete “honeydew” – a sweet, sticky substance – and is sometimes fed on by ants. This isn’t always the case; but in your inspections look for travel pathways of ants up and down the plant where the aphid colonies are. Sometimes the ants will lead you to the aphids that you would have otherwise missed.
Anytime you see any aphids, it is a good practice to set out yellow sticky traps. Aphids are highly attracted to the color yellow, which lures these little monsters into the traps. They are available at most garden centers and will be in squares or strips. Place several of them in the area where you find the aphids, and put out a few more than you might think. They are good inexpensive insurance.
If the aphids have colonized more than about 5% of the bud and young leaves of a plant, or are on more than that amount of your total garden plants, then it’s time for the next round of action.
Beyond physically removing the aphids, there are two approaches to treatment – biological and chemical controls. Biological controls use biology – predatory insects – to eat and control the aphids. Chemical controls are just what they sound like – using sprays of varying toxicity to reduce the aphids’ population.
Using the biological approach first combined with a non-toxic soapy spray is often the knockout punch needed for smaller aphid infestations. Releasing parasitic wasps that lay their eggs inside the aphids, ladybugs, lacewings, soldier beetles and the syrphid fly larvae are all highly effective if done in time, before the aphids’ population explodes. One of the best resources for biological controls is Arbico Organics. They will help you decide what species will work best for your garden situation, how many to release and how many times. Keep in mind that the goal is not to completely eliminate every single aphid, as then the beneficial and predatory insects won’t have a food source. The goal is to keep the aphids controlled, where they aren’t damaging the plants.
Remember, weather can be on your side when dealing with aphids. Heat and high humidity can really knock them back as they are fairly fragile and die off in droves when temperatures are over 90°F.
Soap sprays work by smothering the aphids by coating their skins. Start with a completely harmless soapy water spray like Dr. Bronner’s – using a tablespoon per half gallon in a hand sprayer. Make sure to apply the spray when beneficial insects aren’t around, as they will also be affected. From there, work up to an insecticidal soap like Safer Brand or horticultural oil such as neem oil. With both of these approaches, make sure to cover the underside of the infested leaves well for the smothering effect to work. These are contact controls, and depend on contact with the aphids to work, so they will need to be re-applied as often as needed until you’ve gotten control of the situation. This could mean once a day for a few days, then twice a week for a week or so, then tapering down to once a week. It might well take 2 – 3 weeks to really get a handle on persistent outbreaks, so be patient but persistent!
Moving up the toxicity ladder, multi part sprays such as our Home Garden Bug Solution work very well, but need to be used carefully as they do have a high level of insect toxicity even though they are made with no petrochemical ingredients. If you do need to bring out these big guns, test in a small area to see the effects before spraying your entire garden!
Hopefully you now see that there are a number of ways to reduce and control the pesky aphids in your garden. It all starts with prevention and preparation with improving the soil and balancing the nutrients it needs. From there you now have several new tools in your “pest control” toolbox to help you manage aphids in your garden next growing season.
We were asked to write about our experiences as Slow Food USA delegates to the 2012 Terra Madre conference in Turin, Italy as information and details for the 2014 delegates. Here’s our story!
The Terra Madre gathering was something Cindy and I had heard of several times during our decade long Slow Food membership, most often at Slow Food events in Flagstaff or Phoenix, AZ. Our formal introduction was a presentation by a college student who attended the 2010 event with her family who are farmers from Oregon. The photos and descriptions were sensual and alluring, drawing us into a different world where food is revered and the producers and chefs are celebrated. The young woman was at a loss for words a number of times during the slide presentation and we attributed it to nervousness or lack of public speaking experience. Later on, we would come to realize that there really are no words to describe the entire experience; only bits and pieces, thoughts, ideas, flavors, aromas and sights. Even two years later it is difficult to capture many of the sights, sounds, flavors and aromas with words.
Map of Terra Madre
Once our applications were in, we fervently hoped that we would be chosen as the experiences would be a keystone in our lives, both personally and professionally. You see, we are not only serious foodies, but have an heirloom garden seed business named Terroir Seeds that focuses on why the quality of the soil influences the resulting flavors from the garden so much. We felt that attending Terra Madre, meeting the growers, producers and chefs along with the sights, textures, tastes and scents would better our understanding of food and why its origins are important.
Opening Ceremony Stadium
When the email arrived announcing our selection as Delegates, we began reviewing the events, conference topics and taste workshops along with the International Congress schedule. We had been selected as Congress delegates as well as Terra Madre ones, so had an extra schedule of meetings and presentations from 130 countries around the world. The sheer number of things to do, see and taste was overwhelming! Fortunately, we were able to attend a “Pre-Terra Madre” event hosted by Slow Food Phoenix with other new delegates along with experienced attendees that gave us some very valuable and useful information that made our trip more enjoyable.
Korean Delegate at Opening Ceremony
Probably the single most important tip was that we would be on “Italian time” and not to worry. Things might not seem to be progressing like they would in America, but it would all turn out well in the end. They were right, we did get where we were supposed to be even though there were thousands of people from all around the world speaking many different languages. The logistics must have been a nightmare, but everyone was polite and friendly.
The other great tip was to expect the first day to be very long, exciting and exhausting. We landed in Milan mid-morning and didn’t get to our hotel until after midnight, after a trans-Atlantic flight starting in Phoenix, AZ at 7AM the previous morning. Our schedule didn’t allow us to arrive a day earlier, but if you can it will help to have a full night’s sleep before starting the marathon that is Terra Madre!
Oval Lingotto Building
Another tip that is not immediately obvious, but will prove to be invaluable as time goes on is to take lots and lots of high-quality photos. Documenting the experiences will revive memories that fade shockingly fast. Looking at a single photo, I can still vividly remember the Provolone cheese being opened up early on the second morning. The indescribably delicious and powerful aroma, along with the complex and lasting flavors were an eye-opening experience, showing us that we hadn’t tasted anything close to this in the US.
Handmade Provolone Cheese
When we landed at the airport in Milan, we were with a large group from the USA, along with people from several European, African and Asian countries. The bus ride to Turin was spent getting to know others, finding out what they did for work as well as what things they were doing in their area that related to Slow Food. It was a real eye opener to see how many creative, passionate and dedicated people there were in every conceivable situation all over the world working to make food more accessible, better and healthier for everyone. We felt like we were re-discovering a tribe we belonged to but hadn’t known we had lost. It was a homecoming of sorts, a place the heart knew well but the eye hadn’t yet seen.
Meat Counter at Eataly
After checking in at the Oval Olympic Arena, also known as the Oval Lingotto, we stashed our luggage and wandered over to Eataly for cappuccino and snacks. It was a great introduction to the event, as it seemed to be a Slow Food superstore! Every area in Italy and from other regions of the world was represented, with signs and cards explaining where the food was from and why they were special. We had been advised to eat often the first day and get a cappuccino whenever we started to feel a bit tired. Italian cappuccinos are much smaller than we are used to, so they were the perfect pick-me-up during the entire event.
French Cheeses
Once we had fueled up, we wandered back through the Lingotto Fiere as the booths were finishing set-up. The event is held in part of the repurposed Fiat factory, and is huge. The stroll through the vast building really wet our appetite for the next few days! Several of us made notes on specific booths and stages we wanted to come back to visit. Even after spending most of 3 days in there, we missed seeing a lot. The sheer size is vast, much bigger than the entire Las Vegas convention center or other convention centers we’ve visited, and they are filled with food!
1st Cappuccini
The opening ceremonies were held at the Palasport Olimpico – also known as the Palaisozaki after the Japanese architect Arata Isozaki – where we were bussed and re-deposited our luggage at a baggage claim area. As the arena started to fill up, we talked to more people and snacked on fresh made sandwiches and more cappuccino. The opening ceremony was impressive with a warm welcome from the officials from Turin, along with an incredible flag procession from each country attending. Afterwards, we walked to our group of buses for the ride to the hotel.
1,000 Gardens in Africa Display
The next 4 days were a whirlwind of food tasting, cooking demonstrations, learning the history of a regionally famous food and bumping into all sorts of people, like Alice Waters, Vandana Shiva and the ever-delightful Carlo Petrini. We were continually impressed with how friendly, helpful and engaging the artisans were, eager to share their knowledge and experience of their particular food, along with delicious samples. It was great to spend a little time at a booth, talking with the family that produced the food and learning more about their lives and how much work or experience went into each taste we had.
Alice Waters at Terra Madre
They were equally interested about our lives in America, with most being fascinated when we said we were from Arizona. Many Italians want to see the Grand Canyon, and a surprising number had been there or in other parts of the southwest. They always wanted to compare food notes, what we ate, what we raised or grew and what we considered to be our “traditional” foods. That was difficult, as the USA is truly the melting pot! They were fascinated at the variety of foods we ate on a regular basis and were impressed that we didn’t live off of McDonalds or other fast foods. Yes, American commercialism at its best!
LaVazza Cappuccini
On the other hand, we received a valuable lesson in viewpoint when we were at the La Vazza booth sampling regional coffees paired with a traditional treat. The young woman guiding us through the selections was a student at UniSG – the University of Gastronomic Sciences that is part of Slow Food in Italy. When we remarked on how wonderful it is to have an event like Terra Madre celebrating traditional foodways, she commented that what we were seeing was indeed special, but everyday Italians were much more like Americans in the respect of wanting convenience and “progress” in their food choices, so traditional ways were declining. We were surprised, mainly because of the image of Italy as a bastion of traditional, honored food systems and regions. During our conversation, we learned that there was a very strong movement in Italy to continue the local and regional foods that had become more sustained and successful. Part of this was due to the influence of Slow Food in Italy!
Pizza Workshop
In talking to the growers or vendors about their foods, taste and flavor were always one of the first things to be mentioned or demonstrated. Those were the primary concern, with everything else being secondary. What a refreshing change for us, where we are used to flavor being heavily advertised but rarely well represented! When we would talk about wanting to bring seeds back and introduce those varieties to the American public, the very first comment – always – was, “It won’t taste the same!” They were right, of course, but we were looking to introduce flavors and different varieties of traditional vegetables that are unknown here. After some discussion, several growers understood what we were trying to do, but always came back to the flavor being different. They were happy to see that we were trying to spread the word about the uniqueness of their foods, however.
Genovese Pesto Demonstration
With all of the centuries of traditional food production, some with defined methods dating back 300 to 400 years in an unbroken line, there were definitely creative twists and experimentation represented. Several craft breweries were showcasing their approach to small batch, handmade beer with unusual herbs and spices, all of which were completely different than what craft brewing is in America, but completely delicious. One family of cheese makers from southern Italy stand out in our memory, as the son was telling us that he had been in the international banking business but had returned to making cheese after the economic downturn. He showed us several of the traditional aged cheeses his family had been making for over 100 years. Then, with a bit of awkwardness, he introduced us to his own creative twists – aging cheese in the local winery’s grape must, or crushed grapes, for a completely different approach and beautiful flavor for his goat cheeses. He said that the local area thought him crazy at first, but were starting to come around after several years of tasting his new cheeses.
Lazio Region Cheesemaker
If one story can sum up our experiences at Terra Madre, it would be this: during the International Congress presentations, just before lunch, a young Palestinian woman spoke about the hardships and challenges her community faced in finding land and enough water to grow fresh food for their villages CSA or community supported agriculture program. As she started speaking, the entire room grew quiet and charged with anticipation, waiting to hear what she had to say. Their village was split by the dividing walls, and her talk was charged with emotion and passion. Despite the incredible challenges, she talked about the successes they had gained, growing more and more food to feed themselves and gain a measure of self-respect and resiliency. We broke for lunch after her presentation.
Chile and Garlic Bouquet
Soon after the break a young Israeli man got up to speak, and the room once again became silent and charged with anticipation. After he introduced himself, he stated that not all Israelis supported the current program, nor were all antagonistic against the Palestinian situation. He then described his village’s challenges in obtaining enough land and clean water to grow fresh, healthy food for his community, which was also close to the dividing wall. After a couple of years, they were able to grow more and more food, gaining some independence from the food trucks that so many were living off of.
Both young people exemplified what we saw time and time again at Terra Madre – individuals in all kinds of situations and conditions all around the world working diligently day to day to make a positive difference where they lived, no matter the beginning challenges. It really gave us hope that what Slow Food stands for – good, clean and fair food – is a powerful, positive change in itself.
Salone del Gusto
While we may not agree on many things – religion, politics, race, nationality and economics – we can agree on the foundational importance of food and our need to eat and eat well. Maybe, just maybe, food is that place where we can meet, eat and begin to find more common ground to agree on.
Controlling Aphids Naturally
Aphids are perennial pests that gardeners deal with, often with very mixed results. We’ll show you both prevention and treatment methods for aphids.
Terra Madre from Our View
Terra Madre is a biennial international food conference in Turin, Italy showcasing local food systems and producers from all over the world.