An unexpected experiment

I was surprised, earlier this spring, to notice that the “volunteer” squash – those growing from seeds remaining in the compost we added to the soil – were not only larger and greener than the squash I had transplanted, but, unlike their neighboring transplants, they had almost no yellow-and-black squash beetles crawling on them.

Impatient as I am, I have always bought transplants, believing I would get food sooner. This year, for the first time, I started my own seeds in small pots in our kitchen in late March. Mistake number one: squash grow quickly, and I started them far too early. By late-April, they were healthy and ready for transplant – a month before the weather outside would allow me to do so. By mid-May, they were “leggy,” turning yellow, and we were tripping over them. So I began again. Most of the second round of transplants (pumpkin, acorn squash, butternut squash, yellow squash, zucchini, and an heirloom Hopi squash) were ready when the last frost date rolled around (Memorial Day weekend here). I added a few Delicota transplants from a nearby nursery. I covered everything with a fabric row cover to give them some extra warmth and a “pest-free” head start. 

I covered and left three of the “mystery” volunteers as well. Hence, the unexpected experiment. Within a few weeks, the small volunteers had outgrown the transplants; they were larger and their leaves were a deeper green (a sign of health). That wasn’t altogether surprising. Transplanting stresses plants, and, I later read, squash are particularly vulnerable to transplant stress. Over time, the volunteers (which turned out to be both pumpkin and zucchini) continued to outgrow the transplants.

But the real surprise came as I made my daily rounds to pick the squash beetles off the plants. While I picked dozens of beetles from the transplanted squash, I rarely found even one on the volunteer plants.  I knew that stronger, healthier plants are better able to withstand the onslaught of pests and disease. But I had no idea that somehow (chemical changes leading to a difference in smell or taste?), they were less attractive to the pests as well. I’ve never seen mention of this in any of the organic pest control books I’ve read. 

Growing food is a science, as well as an art, requiring close, constant observation and ongoing experimentation. As soon as I say “science,” many people think immediately of professional researchers, working in labs or “test fields,” conducting carefully designed, controlled experiments and putting out authoritative reports. But the most successful farmers – whether running commercial operations or just feeding their families – have always been scientists, developing a deep base of knowledge about the particular plants, environmental conditions, and micro-climates where they live.

Some of that knowledge has been passed down, like the Native American realization that corn, squash and beans – which they called the “Three Sisters – grown together will yield more food than any one of those crops grown separately. (Academic scientists, seeking to verify that knowledge, have concluded that the sugars in the corn roots nourish the specialized bacteria on the bean roots, which in turn, fix nitrogen that the heavy-feeding squash require. Finally, the squash, growing as a broad “ground cover” like the pumpkin below, shades out weeds that would otherwise compete with the taller beans and corn.) 

Unfortunately much hard-won “local” knowledge has been dismissed, and then lost, by our society’s bias toward “professional” science. Personally, I like the definition of “science” used by a former teacher of mine, Davydd Greenwood, and his colleague, Morton Levin. “Scientific research,” they wrote, is "an investigative activity capable of discovering the world is or is not organized as our preconceptions lead us to expect and suggesting grounded ways of understanding and acting on it."

Growing food – like most other human endeavors – lends itself to that kind of science. There are the organized “experiments,” growing different varieties of a particular crop, for example, to see which do best in the soil and micro-climates in one’s field or yard. (Below, for example, is a rare heirloom Hopi squash that we are experimenting with to see how it fares in our gardens. It will turn a deep orange-red when mature and is reported to store well through the winter). 

There are the careful observations of what is already growing and how it fares. We noticed, for example, that the daffodils near our home’s southern wall bloomed two to three weeks earlier than the daffodils in the bed 50 feet away, and that the last frost date close to the house was almost a month earlier in the spring (and a month later in the fall) than in other places in our yard. That led us to plant the vulnerable apricot tree right along the house's southern wall, in a micro-climate that is closer to “zone 6” than to our area’s general climate ranking as “zone 5.”

Finally, there are numerous unplanned experiments – like with my squash – that arise day-to-day. I don’t yet know why the squash beetles chose the transplants over the volunteers. Nor do I know what the beetles would do if no transplants were available. But I plan to keep close watch and compare notes with other growers. And next year, I’ll be poking squash seeds in the ground before the last freeze, experimenting with growing them like “volunteers.”