I just had a lovely phone call with my sister. One discouraging note was her recent decision to finally give in and purchase some pesticide spray. (She’s usually a greenie, but as she put it, “I just want to have some plants.”)
Her tomatoes and other starts have been eaten down to little nubs several years running, despite trying various methods like beer traps and soap sprays. She’s in sunny southern California, so the tricks we learned in our mother’s garden in rainy Oregon may not entirely apply.
I was concerned of course. Not only on principle (I myself will accept garden failure or eat grasshoppers before I would spray chemical pesticides) but also from the heart, because I love my sister and her family. Their branch of my extended family is already dealing with a restricted diet due to food allergies, and the chemical and social pressures of the greater Los Angeles environment.
Looking for online resources, I found the following excellent article from Mother Earth News, circa 2011, based on a survey of gardeners from all regions of North America:
For North American readers this info seems well-researched, and has loads of useful links to sub-articles on beneficial insects, specific species and tactics, differences in results between different regions, and more. Some key pests from other regions may not be mentioned, but many of those described are common garden pests worldwide. Having lived in both regions, I can verify that slugs are the #1 pest in the rainy Pacific NW, while grasshoppers are a bigger issue in the inland / Rockies region.
Controls like hand-picking and Bt show up as very effective on many pests. Other simple steps like rigid collars or row covers are also popular. Beneficial insects and companion planting get mixed results (they’re harder to target, after all), but there are some fascinating suggestions. All the recommendations are based on responses by actual gardeners, not university test plots or industrial farmers.
Now for the doom and gloom side of the argument:
Here’s an article highlighting some problems of the pesticide approach:
The biggest concerns I have in my sister’s case are:
- Bioaccumulation – pesticides concentrate in foods, body fat and breast milk, and I would prefer that my young school-aged nieces get as little exposure as possible. These are mostly food plants she’s trying to protect.
- Diminishing effects – my sister wants to spray “just for the first few weeks” to get the plants established, but most pesticides breed resistant bugs, and they can also reduce the health of the plants encouraging further infestation. It’s possible that some of her current problems can even be traced to residual pesticides or herbicides from previous property owners, creating ill health for the plants.
She will be embarking on the pesticide ‘treadmill’.
- Just plain ignorance. Most pesticides aren’t well labeled, and many are not well-tested for long-term, cumulative health effects either in humans or for wildlife and soil biota. I have spent four years teaching basic chemistry, and I doubt I could tell my sister whether her chosen pesticide is “safe.” She has an art and communications degree, and while she’s no dummy, there is simply no way for her to know until it’s too late… and even then, the level of knowledge available will likely still be a labyrinth of doubts rather than a definitive problem and cure. The best cure is prevention: if you don’t know what’s in it, and what those words mean for your long-term health, don’t use it.
I can’t make my sister’s choices for her, but I can find the best resources and make the information available. Hopefully with access to info on specific pests and effective, non-poisonous control tactics, she’ll find those mysterious chemicals are not necessary after all.