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Squash Vine Borers

    Date Posted: Tue, Aug 24 - 1:57 am

    Question

  • Hi there! Thank you so much for doing this! I have a couple questions on squash vine borers, which have been a HUGE issue in my garden this year. I have been surgically removing the larvae from my curcurbit vines every few days for over two months now (along the way losing both of my zucchini plants and one patty pan squash plant; now I have one patty pan and 4 pumpkin plants remaining). My questions are: How much longer should I expect new larvae to bore into my plants? And is there anything I can do next season to organically prevent these pests (or perhaps control them in a less laborious fashion!)?
  • Answer

  • Hello! Thank you for your question. It sounds like you have had a challenging season with this difficult pest. Your surgical removal of the larvae is one part of the solution, and it sounds like you have mastered that particular process. There are other things you can do as well. To answer your first question, it is important to understand the lifecycle of the squash vine borer. Eggs will first appear in our area in May, will hatch in early summer, and then the larvae will bore into the squash stem to feed for up to 4 weeks. When the larvae are mature at 4-6 weeks, they will leave the vine and the dig 1-2 inches in the soil to pupate. In our climate, we can sometimes have 2 generations of larvae in a season. So unfortunately, once infested, this pest can present a problem for most of the growing season. In addition to the surgical removal process of the larvae in the stems, you can also use an organically approved insecticide such as Spinosad or Bacillus thuringiensis (Bt). Apply the product on the leaf stems and the main stem of the plant - do not spray the flowers. Apply one of these insecticides once per week during the growing season. It will kill the borer's eggs and larvae quickly. Again, these are organically approved products, and we recommend staying away from any synthetic, non-organic insecticides. Another method for prevention early in the season is to cover the young plants with a floating row cover until flowering occurs. The row cover will keep out the insect in the critical early part of the season, and will still allow sun, water, and air to get to the plant. Once flowering begins, remove the cover to ensure pollination is not disrupted. If or when you do have an infected vine(s), seal them in a plastic bag before the larvae pupate. This will break the lifecycle of the squash vine borer. And finally, the other important practice is to till under all crop debris after harvest, which also disrupts larvae in the soil, and prevents buildup of the squash borer population. Implementation of these practices should minimize the need for constant surgical removal of the larvae, and yield healthier plants and better crop. Good luck, and please reach out with any other questions!

Squash Bug Control

    Date Posted: Sun, Aug 22 - 3:10 pm

    Question

  • I have been having a hard year with squash bugs taking over my zucchini plants. I am wondering if you have any tips on how to prepare the soil this winter to decrease their activity next season. Thank you!
  • Answer

  • Good morning! Thank you for your question. You are certainly a step ahead in that you have identified the pest, and have probably read about effective means to control and hopefully rid many of the insects during the growing season. Nevertheless, they are difficult to eradicate. You are smart to be thinking about ways to overwinter the garden to minimize the problem next spring. Do you use mulch around your zucchini plants? Mulches give adult squash bugs a place to overwinter, and you want to remove that mulch if you have used it. Straw is a better alternative to use around these plants in the growing season. As fall/winter approaches, you want to be sure and clean your garden of old vines, crop, and leaf debris where adult bugs will hide over the winter. Squash bugs will rarely survive cold winters without places to hide. However, Richmond has been known to have very mild winters, and you surely don't want to give these bugs a place to hide. Once you have removed all debris (and mulch, if you have it), till the soil. This also helps eliminate the pests. If you have the room in your garden (which most city properties do not), it is also helpful to rotate your crops year to year to keep down insect population. But the best thing to do is completely clear the garden of all debris for the winter, and till the soil. One tip for next spring/summer, is to place boards or old shingles on the ground next to the garden (especially at night time). Squash bugs love to hide under these, and they make excellent traps for collecting the bugs in the morning, and then placing the bugs in a bucket of soapy water. And of course, regular inspection during the early growing season to collect these bugs from your plants helps as well. But definitely follow the guidelines for garden cleanup and tilling to properly overwinter, and that will certainly get you off to a clean start in the spring!