As an organic gardener, I am often faced with questions from conventional agriculturists about how I deal with pests. The collective wisdom about this boils down to one essential fact. If your plants are healthy and unstressed, they are not susceptible to insect pests. You can find a long and scholarly dissertation on this subject in Eliot Coleman’s book “The New Organic Grower” in chapters 17 and 18.
To complicate matters further, insect pests are quite adaptable and will select over generations for behaviors and genetic makeup that make them resistant to the form of control being used. Most of us are aware of how easily insects become resistant to chemical pesticides, but even insects controlled by use of sticky traps get selected for resistance. The bugs that aren’t attracted to the traps reproduce and eventually you have a strain of insect that used to be controllable by use of sticky traps but is not any more.
So the bottom line in organic pest control is to make sure your plants are growing in as healthy and nutritious environment as possible. The name of the game is COMPOST, one of nature’s true miracles.
That being said, when you reach the end of the growing season and the soil is depleted, or the day length and temperatures are not ideal, one often finds that the pests that have been absent most of the summer show up in droves. And there are some things, like it or not, that just love to feast on healthy plants. Flea beetles and cabbage looper butterfly larvae are notorious in this regard.
My favorite way of dealing with non-insect pests like deer and rabbits and rodents is a fine physical barrier. Good fences make good neighbors, even when you are talking about animals that want to eat your veggies. This shot shows our grand fence. Waist high cedar planks topped with another three feet of chicken wire.
This shot also shows the other physical barrier we use: the floating row cover. You can see the light plastic arches used to support the row cover above the plants. You don’t have to use supports, the row cover is so light it will rest on the plants without hurting them, but I find that they grow better if they don’t have to push up against even that light cover.
The next photos show how the row cover looks when deployed.
I use long pieces of rebar to hold the floating row cover down in the wind. The rebar slips down neatly between the arch supports and the bed edge.
This is how broccoli that comes out of my garden looks. Note the lack of damage to the leaves. An additional benefit to the floating row cover is that it cuts down on the heat gain just enough that my broccoli produces side shoots all summer, even during the heat of July and August.
So, how do I deal with the flush of herbivores when the conditions in the garden get less than optimum for the plants? When they show up, I try to be vigilant and go out early in the morning when it is cool and pick the adults off execute them. As far as I know, there isn’t a bug species around that has developed resistance to being squished between a thumb and forefinger.
Some people are squeamish about this, but I have found that there is a certain satisfaction to murdering bugs that are killing my plants. Upon occasion, I have found myself musing about this process when I am in the middle of a big campaign. One year there were thousands of harlequin beetles on my cleome plants. I went about systematically killing them for several days before I finally gave up the battle and pulled the plants out. When I did that, I would put a big black garbage bag over the plant and then pull them up by the roots, thereby entrapping the beetles within the garbage bag. I sealed the bags up and stuck them out in the sun to broil.
While I was squashing the beetles, I thought about the millions of dollars women spend courtesy of the cosmetic industry in an effort to make their skin soft and wrinkle free. “Hmm,” I thought to myself. “If someone did a study that proved that rubbing harlequin beetle juice into the skin around your eyes and mouth prevented or cured wrinkles, I could charge people for the privilege of coming out here and smashing these bugs for me.”
Other than the entrapping within a plastic bag method, another method I find works wonders in killing bugs is the funeral pyre method.
I build a good sized, very hot fire in the bonfire circle, and then pull infested plants and burn them. You have to be careful and deliberate about this process, because you can smother the fire if you put too much green stuff on it at once. Then you perforce become a charcoal maker.
This is why I sometimes burn infested plants. There are too many of them to catch. Or there are thousands of the tiny nymphs hiding everywhere.
Worst of all is the egg deposits. These are well hidden and hard to find. I prefer to burn plants that have turned up with large populations of herbivores. Composting does not always kill the eggs, and then when you put the compost out in the garden you have repopulated the pests.
I also burn the refuse of plants that tend to be susceptible to fungi and bacterial blights, just to make sure that those things don’t get perpetuated in the garden.
All in all, I find a lot of satisfaction in the personal destruction of pests. And frustrating the rabbits and deer is a lot of fun too.