(Editors note: I have updated information in a new article on this subject. You can see it at Controlling Squash Borer, Part II.)
FOR THE LAST TWO YEARS, squash borer (aka squash vine borer) has ruined my zucchini and pumpkin, and I suspect that it ended my cucumber prematurely, too. It’s a shame because zucchini is one of the vegetables that my kids will eat without me having to sit on them first.
Squash borer is the larva of the moth shown in the photo below. The moth has a wing span of about one inch. It lays reddish-brown eggs on the host plant. When an egg hatches, a one-inch, white lava with a brown head emerges. The larva bores its way into the stem of the squash plant, typically in the first inch or two above the ground, leaving a saw dust like material called frass. The plant wilts and then dies.
After two years of trying to grow pumpkin and zucchini unsuccessfully, I was almost to the point where I was ready to give up and not grow any cucurbits for the next few years to see if I could eliminate the pest. It was particularly discouraging because most people think of zucchini as being easy to grow.
My three-part plan for controlling squash vine borer
After researching how to control squash vine borer, I’ve decided to attack the problem with a three-part plan. Here it is:
1. Start plants late. I plan to transplant zucchini and cucumber seedlings during the first week of July, hoping that the squash borer moth will have already attempted to lay its eggs and passed on. In areas with a cold winter, there is only one generation of squash borer. So with any luck, I will have missed the onslaught. As heat-loving plants, July should be good for zucchini and cucumber, as long as I can keep them watered. I’d expect to get fruit during the second week of August.
2. Plant second crop one week later. In case the first crop gets infected, I’m going to wait a week and plant a second crop (succession planting). If the first crop seems to show signs of being infected, I’m going to immediately take it out so the second crop doesn’t get infected from the first.
3. Protect vines with tin foil. When I first plant the seedlings, I’m going to wrap the stems, starting just under the soil, with tin foil. As the plants grow the tin foil will act as a barrier and prevent moths from laying eggs on the vines.
The video below from The Urban Homesteader shows exactly how I’m going to apply the foil to protect the zucchini and cucumber.
Other organic methods of protecting the plants include floating row covers to stop the moths from laying eggs on the host plant, wrapping stems in toilet paper rolls, putting panty hose around the vines and applying insecticidal soap to destroy eggs. I’m hoping that I won’t need to use any of these additional methods.
If you have an organic method that prevents squash vine borer from eating your cucurbits alive, let us know in the comment section below.
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