Take appropriate measures to make room for beneficial insects

-A A +A

Chris Coulter

Agricultural Columnist


Everybody seems to have a different level of tolerance to weeds. For those with the golf-course mentality, there shouldn’t be a weed out of place, and all blades of grass should measure within a half inch of each other. A stray dandelion in a field of green would be cause to haul out the herbicide tank and bring down chemical Hades. If the dandelion were especially menacing, it may even have to be attacked with napalm. I’m not in that camp.

I’m more in the live-and-let-live camp, and have a fairly high tolerance to weeds — if they are in the right place. Now don’t get me wrong, weeds in one of our vegetable fields get no mercy, and we deal with them quickly. You especially don’t want to let a weed reproduce itself, as its prodigy will be with you for years after. But I don’t have the time or desire to police the whole farm for undesirable weed species. In fact, I’ve learned over the years that a farm operates better as an agro-ecosystem than one in which we exert chemical controls to the point we create a sterile green parking lot.

A weed may be considered a plant that is in the wrong place, and that can certainly be true. But take that same plant and put it in its proper place, and it may be more beneficial than problematic. Now all this talk about weeds takes us to the main topic — insects. Just like a plant in our potato patch is a weed, an insect munching on our broccoli is also a problem. However, the intent of insects is a little trickier to gauge, as there are many insects that actually feed on the insects that feed on our broccoli. Other insects pollinate our crops. Both types we refer to as beneficial insects.

You want to encourage these insects to populate your garden as they are a natural means to keep the bad insects in check without resorting to chemical sprays. Now depending on the scale on which you are growing, it may not mean you can totally do without other insect-control measures, but it certainly does help to let the beneficial do their part. If you automatically spray every time you see an insect, you may inadvertently be killing off the good guys, and giving a leg up to the real pests in the future.

Green lacewings, ladybugs, praying mantises, and cool-sounding bugs like the “assassin bug” all eat other insects. In some cases, like with parasitic wasps, they lay their eggs in ravaging caterpillars where they incubate until they sort of “pop.” Also cool. Now here is the key. These beneficial insects need more habitat that your vegetable garden is going to provide. Many feed on nectar provided by “weeds” and most need out-of-the-way areas for egg-laying and resting. A manicured lawn does not have such places. A beneficial insect in a lawn is about like me or you standing in the middle of the Sahara Desert with half a bottle of water. Not much to drink and nothing to eat. So, a thoughtful gardener will provide places for these bugs to hang out, have a snack, and get a little breeding in.

One easy option to aid beneficial insects is to just leave some areas un-mowed. Often beneficial plants will show up on their own accord, just as they would be present if we weren’t around to interfere. The downside to this natural approach is that it may take a few years for the beneficial plants to grow up, and if you have a weed problem (like the evil Johnson grass) the desirable plants may never be able to compete. Then you’ll just have a patch of Johnson grass that spreads to your neighbor’s yard and makes them angry. Better is to set aside an area and plant it with specifically chosen beneficial plants that attract and provide for beneficial insects. In the next column we will talk about specific plants and how to go about starting your “pollinator garden” as I like to call it.

Chris Coulter and his wife, Amy, operate Coulter’s Good Earth Farm in Nelson County, where they raise sustainably-grown vegetables, fruit, animals and children.