I've been an organic gardener for decades. But that doesn't mean my thoughts and practices for controlling pests, particularly destructive insect pests, hasn't changed. As any gardener knows, gardening isn't a static activity. Nature, garden technologies and our own preferences evolve over time.
I've seen it first hand. I never really was too concerned about spraying organic pesticides in my younger days, thinking they were vastly superior and safer to chemical pesticides. But we know that any pesticide can be harmful to a wide range of insects, birds, and soil creatures. Biological sprays, such as spinosad and even Bacillus thuringiensis (Bt), can have harmful effects on beneficial insects and pollinators.
I find my desire to do no harm to soil, insect and animal life has become more important than growing the perfect squash or rose. But, then again, we all garden because we want an abundance of food and flowers in our life. So, how do we garden, grow beautiful and productive plants and still have the least impact on the world around us?
Here's three practices, beyond spraying, I'm using lots more in our garden. I'm open to new and different ideas if you have some suggestions on what you're using.
Controlling Insect Pests
I'm going to focus this article just on insect pest controls. My first step in pest control has always been prevention. If I can grow a variety of winter squash (butternut) that is less susceptible to the squash vine borer, then I will. If I can rotate crops to prevent specific pest populations from building up in the soil, so be it. If I can remove heavily infested plants before the insects spread, then I'll make the sacrifice. If my garden is generally healthy and diverse with plant life, it's more likely to attract beneficial insects, such as ladybugs, that can help control insect pests.
New Row Covers
But, as we all know, sometimes good gardening practices just aren't enough. One of the techniques I've been using with regularity is barriers. The adult stage of many insect pests, such as leaf miners, leek moth, cabbageworms and squash vine borers, is an adult fly or butterfly that lays eggs that turn into caterpillars. Barriers are simple. Block the adult from laying the eggs, then caterpillars won't form. I used to use lightweight floating row covers. But after a season or two they would tear and leave me with duct taped row covers for the rest of the season.
My new barrier of choice is micro mesh. This window screen-like material is long lasting, durable, has very small holes that insects can't penetrate, but let's through light and water. Also, I like seeing through the mesh and noticing any errant attacks. I use micro mesh with tall hoops from planting to harvest on all my Brassicas to keep cabbage worms and loopers off the plants. I use it on my Alliums to keep the leek moth away from my onions and leeks. I even use it, early in the season, to protect squash and cucumbers from wind and pests. Of course, I remove it when they start to flower for pollination. Other than the aesthetic of seeing covers on my beds, I love it. It's worth the investment.
By the way, a good barrier for slugs and snails in the garden is sheep's wool. Depending on where you live, use raw sheep's wool or purchase wool pellets. Mulch the garden plants with it and the slugs and snails stay away from this naturally scratchy material.
HandPicking
One of the "go to" controls of insect pests is hand picking the adults. While this works, sometimes it's hard to catch the flying adults. I find an easier control is to squish the eggs. The insect eggs of many pests, such as Colorado potato beetle and squash bugs, are obvious if you look under the leaves. They tend to be laid in groups and have bright colors. Start looking early in the season for the eggs and when found, squish away. It's a nice, end of the day activity to stroll in the garden for a few minutes, flip over squash or potato leaves and look for eggs. You may not get them all, but that's another tenant of organic gardening. We aren't looking for complete control, just enough for the plants to produce well.
Traps
A third method I'm using more is traps. Insect traps for home garden pest control have become more mainstream. Sticky traps for leaf miners, white flies and cucumber beetles and pheromone traps for Japanese beetles, codling moth, and apple maggots, are good ways to reduce pest numbers without having to do much work. Sticky traps use blue, yellow or white color to attract insects and are coated with a sticky substance that kills the landing insects. Although sometimes bees and beneficials will also get trapped, this method is much safer than sprays.
The key with Japanese beetle traps is placement. Place traps a few hundred feet from your garden and do perimeter trapping around your yard to catch beetles flying through. Place the traps 3 to 4 feet off the ground and empty them often. This combined with spraying beneficial nematodes in spring and early fall as a parasite of the larvae stage of the Japanese beetle in the ground has reduced our Japanese beetle problem dramatically.
Charlie Nardozzi is an award winning, nationally recognized garden writer, speaker, radio, and television personality. He has worked for more than 30 years bringing expert gardening information to home gardeners through radio, television, talks, tours, on-line, and the printed page. Charlie delights in making gardening information simple, easy, fun and accessible to everyone. He's the author of 6 books, has three radio shows in New England and a TV show. He leads Garden Tours around the world and consults with organizations and companies about gardening programs. See more about him at Gardening With Charlie.
