How to Grow Plants that are Pest and Disease-Proof
Every gardener has had their struggles with pests and diseases like aphids, fungus gnats, and powdery mildew. In fact, in a survey we ran of almost 300 gardeners, more than one third cited pests as their biggest gardening challenge. Diseases can also wreak havoc on a garden, as many a blight-battling tomato grower can attest.
But what if I told you that healthy plants, and I mean truly healthy plants, are pest-proof? Disease-proof?
This statement may seem bold, but scientists have been researching plant health for decades and are coming out with interesting findings that show just that. Here’s how it works: when plants are truly healthy, they synthesize more and more complex compounds such as proteins, lipids, and secondary metabolites. You can tell when a plant is truly healthy by the taste–a healthy carrot will taste delicious because it contains compounds like antioxidants and phytonutrients. According to the Real Food Campaign, a survey aimed at understanding nutrient density in crops, found “significant variation (up to 200:1) in antioxidants, polyphenols and minerals in carrots and spinach” [1]. Clearly, not all carrots are equal. Growing methods, genetics, and many other factors play a part in determining how delicious and nutritious your carrot will be.
But how does this tie into disease and pest-resistance? Let’s take a look at the Plant Health Pyramid, developed by John Kempf, the founder of Advancing Eco Agriculture and a top expert in the field of biological and regenerative farming [2]. The pyramid, pictured below, details the different levels of plant health, with nutrient synthesis as the differentiating factor.
Only the first two levels of plant health can be achieved using chemistry, meaning conventional farms using inorganic fertilizers are limited to these two levels. The next two levels, however, are based on what John Kempf calls “vigorous biology”, by which he means an active soil microbiome. The first two levels of the pyramid allow plants to synthesize standard sugars and proteins, meaning they can grow leaves, stems, roots, and fruiting bodies. However, the next two levels allow plants to synthesize lipids and plant secondary metabolites (PSMs), meaning they can grow more nutrient-dense crops as well as becoming pest-resistant due to the more complex compounds which are inedible to pests.
Another way to think about this is to ask why pests and diseases are eating your plants. The answer is that mother nature only sends who she sees your crops fit for. If your plants are fit for diseases (bacteria and fungi), then it means that their compounds are so simple that even single-celled organisms can digest them. If mother nature sends pests like aphids and potato beetles, then your plants are a little bit better–they require multi-celled organisms to digest them. However, if she sends slugs, birds, rabbits, and deer to nibble your crops, then you know you’re growing plants that are worthy of animals and require more complex digestive systems to break them down.
So now that we understand that the soil microbiome fuels plant health by allowing plants to synthesize more complex compounds, how can we improve our soil?
That’s where regenerative methods like no-till farming, no-dig gardening, and creating bio-active compost come in. Take a look at the ReGen Store for some recommendations on garden amendments to feed your soil and help your plants flourish!
[1] RFC 2018 Final Report — The Real Food Campaign Lab
[2] AEA | Regenerative Agriculture | John Kempf (advancingecoag.com)
