Saturday, July 26, 2014

Handling the annual plague of locusts

Taking a rest from general wickedness
Late summer is harvest time for many of us.  Squash, tomatoes, and watermelons are ripe, sweet corn is almost ready, and baby winter squash are growing on the vine. Untended herbs like basil and cilantro are bolting, and they provide a little extra nourishment for the beneficial insects that call our gardens home. However, the dog days of summer can mean another thing to those of us in western states: grasshoppers.

Texas and much of the west seem to be inundated by grasshoppers every summer.  At least as far back as 1946 it was recorded that in July, when the temperatures hit triple digits and flowers cease blooming, a plague of grasshoppers descend1. I decided to look into organic control options after losing my entire sweet corn and bean crops to grasshoppers this year.

What causes the outbreaks of these voracious hordes? Well, first, we removed most of their predators. Foxes, coyotes, and other small and medium sized mammals find grasshoppers delicious. Birds, spiders, and blister beetles also treat grasshopper as a delicacy. If your garden, like mine, is a small patch in an urban area you may lack the natural predation necessary to keep grasshoppers under control.  Additionally, warm, dry conditions are excellent for grasshopper development- this is why their populations tend to explode during the hottest part of the summer. Extended periods of cool, wet weather suppress their development.

Grasshoppers are not easy to control. If you’ve ever walked through a heavily infested pasture and seen them flinging themselves wildly in all directions, you recognize that they are highly mobile creatures. Because keeping them out of your garden is a largely futile task, you could consider changing your cultural practices. Corn and beans are highly preferred by grasshoppers, while tomatoes and squash are avoided. If, like me, you are unwilling to pass on sweet corn, you could consider timing your planting to avoid grasshopper season.

One of my favorite ideas for grasshopper control is to use domesticated versions of their natural predators: chickens. A number of gardeners have experimented with building ‘chicken moats’ around their gardens. Your chickens get a little extra nutrition, and your crops are spared! For those of us without backyard chickens, coating your crops with kaolin clay, neem and soapy water all have variable efficacy and are worth a shot. Loose fabric barriers around your crops can also provide some relief. Lastly, a ‘trap crop’ of unmown grass may lure the local grasshopper population away from your vegetables. Good luck, and happy gardening!


1Dyksterhuis, Edsko Jerry. "The vegetation of the Fort Worth prairie." Ecological Monographs 16.1 (1946): 2-29.


  1. I enjoyed watching a Bluejay and a Cardinal fight over a grasshopper in my backyard yesterday. It looked like a choreographed scene from Fellini's circus. The Bluejay won.

  2. I'm no gardener, but I don't believe you'll get any tomatoes in triple digit heat because the blossoms won't "set".