back | home |

Problem & Solution
January/February 2018

Subscribe to Texas Gardener!

Problem: We just pulled up the dead vines from butternut and spaghetti squash, both planted in the same bed. We found nematodes on one set of roots. How do I treat them? And will I be able to use that bed in the spring?

Jo Ann Wiggins

Solution: The best way to control nematodes is to practice crop rotation. Sometimes that can be difficult if you have a small garden. When you rotate crops, be sure to follow susceptible crops with non-susceptible crops. Corn and onions are good crops to follow susceptible ones like okra. You can also solarize the soil in July and August to kill many of the nematodes. Rototill the soil and cover with plastic. This needs to be repeated several times and may not be worth the effort for many gardeners. Another approach is to plant cereal rye (Elbon is a good one developed by the Noble Foundation) in the affected area in the fall. Then mow and rototill the crop into the soil in the spring two to six weeks before planting. As the rye decomposes, it releases a chemical that kills the nematodes.

Topless Squash?
Problem: Patty Leander recently gave a presentation on vegetable gardening to the Williamson County Master Gardening class in Georgetown. I was one of the students who heard the presentation. During one of the breaks for snacks I asked about how to prevent squash borers from destroying my crop. Patty advised covering the plant with netting to keep out the beetles that lay the eggs which eventually grow into larvae that destroy the squash.

I followed her suggestion and have had good results. However, I have developed a new respect for bees and other pollinators when I had to artificially pollinate the squash flowers with a Q-Tip. While doing this work I noticed some bees actually working the plants. I was delighted to have their assistance.

Is the beetle that causes the squash-borer problem nocturnal? Could I open the covering during the day, say around noon to let the bees do their work?

Any guidance you can provide would be appreciated.

John Nelson

Solution: Good question, John, but first, let’s clear up a not-so-minor detail — it is a moth, not a beetle that lays the eggs that hatch into borers. The squash-vine-borer moth visits plants during the day, and I have seen the female moth laying eggs in my garden in the morning as well as in the afternoon. Unfortunately, bees are most active in the morning when squash flowers are open and receptive to pollination, which means if you uncover plants for the bees, the moths will also have access. I know of many gardeners who uncover plants in the morning to allow pollinators to visit and then inspect their plants carefully for squash-vine-borer moths or eggs before replacing the cover.

An alternate method of exclusion is to keep plants covered with rowcover or Micromesh netting for the first five to six weeks of growth, right up until the female flowers start to open, then remove the netting so the pollinators can do their work. This means the moth can do her “work” as well, but usually by the time the larvae hatch and burrow into the stem, the plant has had time to produce a number of fruit. Trying to outsmart a squash-vine-borer moth is a time-consuming effort and may not appeal to every gardener.