Author: GTF Office

Diversity as an Organic Pest Control

We have all had the experience of finding the occasional beetle in a salad or a slug in a head of cabbage. When we encounter such a thing, we have to decide how we feel about it. But it’s hard to know what to think, and there is so much more to think about beyond what meets the eye.

On occasion we’ll get a call from a chef who bought our produce saying that an upset customer found a bug in their salad. We thought it was important to tell our customer base more about the truth behind that bug in the salad mix, and why it is actually something to make you feel better about your food rather than worse.

So why would anyone feel good about finding a bug in their salad? There are three main reasons why this would be the case, which I’ll get to in a bit. But first, it is essential to understand the concept of the microbiome. The microbiome is the ecosystem of non-human lifeforms that exists in your digestive system to regulate your digestive and mental health. Having a diverse microbiome is a healthy microbiome. This is because a diversity of microbes can protect a diversity of attacks on your health. A small amount of “bad” microbes cannot take hold and create an infection because they have to compete for space and resources with the diversity of beneficial microbes present. The same is true of the ecosystem outside our bodies. A diverse ecosystem is a health ecosystem. When a farm’s ecosystem has a diversity of bugs present, it is harder for one bug to become a major infestation.

The first reason why a bug in your salad is a good thing is that we do not use any broad-spectrum pesticides. Broad spectrum pesticides eliminate all forms of bug life within a certain category, whether they’re beneficial, indifferent, or damaging to the crop being “protected.” The ecosystem then has such a lack of diversity that it is essentially a blank substrate that can be easily taken over by a pest again, rather than kept in balance by the multitude of different kinds of critters all vying for the same space.

Also, broad-spectrum pesticides create heavy selection pressure on pest populations, forcing them to rapidly develop resistance to the chemicals being dumped onto the ground. This can quickly lead to the creation of what are commonly referred to as super bugs that are so resistant to our methods to control them that complete crop failure becomes a likely risk. Additionally, there are many other negative environmental side-effects of broad-spectrum pesticides aside from the fact that you’ll make pest control harder for yourself the following season. As our agronomist John Yeo takes on pests on the farm, he remembers Jerry Mahoney’s quote, “If we poison the earth, we’re poisoning ourselves.”

Secondly, broad spectrum pesticides are not good for your health in a more direct way than harming the environment. Anything that is designed to blindly destroy life should not go into your body. Of course there is a system in place that is designed to make sure that anything applied to food crops does not harm you, but this classification system is flawed. In simplified terms, for a pesticide to be approved for use, it must be classified under “non-mammalian toxicity.” But this is highly problematic, as the majority of cells in your body are not actually mammalian. They are protozoan, bacterial, fungal, etc. Just as described above, a healthy microbiome is a diverse microbiome.

And lastly, on our farm we feel very strongly about never spraying anything on leafy greens specifically, as they will be consumed raw. That means no organically certified pesticides either. Straight up nothing goes on greens that you will put into your body raw. Leafy greens such as lettuce, spinach, and arugula are very delicate and must be treated as such. To spray something on a leafy green is to eat what you spray, and we take that reality very seriously.

So what do we do to control pests on our farm? Our main control methods are exclusion and staying in tune with the annual rhythms of pest populations. Exclusion controls pests by creating a barrier between them and the plants. For our outdoor greens we put floating row cover, a cheese-cloth like fabric, over the greens and just lift it up when we need to harvest. For crops inside hoop houses, we hang netting over the ends of the house to keep bugs from getting in.

Working with the natural cycles of pest populations is also very important. There will always be certain times of year when pest populations reach their climax. It’s like clockwork. During the times when we know aphids will be rampant, we don’t harvest the crops that they have infested. We wait it out, move on to the next planting, and go back to the old planting after the aphids are gone and it has produced a new set of shoots to harvest.

We also focus heavily on interplanting insectary plants to encourage the growth of beneficial bugs who like to eat pests. Currently, we plant lots of alyssum, and in the past we have also used calendula and phacelia. Alyssum is excellent at attracting wasps that eat aphids and thrips, which are major pests on our farm.

At the very bottom of our pest control repertoire are organically certified sprays, of which we use only three. The most commonly used spray is Surround, a brand of kaolinite clay that is very fine that we spray on winter squash seedlings to protect them from cucumber beetles. The second is BT, a bacterium known as Bacillus thuringiensis that is a naturally-occurring bacteria that lives in the soil. We spray it on Napa cabbage seedlings to prevent moths from laying their caterpillar eggs on them. Lastly, we will use Pyganic, a chrysanthemum derivative, on our pepper seedlings to protect them from aphids. In all of these cases, the crops get sprayed at a very young age to get them through to when they will be strong enough to protect themselves.

If you are reading this, you are likely already someone who is able to choose to pay the extra dollar for organic produce for ethical and health-related reasons. You probably already know that conventional food production is rife with environmental degradation, minimal nutritive quality, and a corporate-controlled suppression of science. But perhaps you didn’t know that finding a beetle in your salad is a physical embodiment of environmental and nutritive health. Either you see a beetle on occasion and you know that you’re eating real food, or you never see any sign of life on your food and you know that it’s been eradicated.

Diversity is what it all comes down to. Diversity is what we work to preserve.

Delicious, nutritious diversity.

By Laura Bennett