I try to garden without pesticides, organic or otherwise because even “organic” pesticides can have unintended consequences in a home garden (more on that in another rant/post). But then, there are some bugs you just can’t do much about. In central Maryland, that would be the squash vine borer (SVB).
The SVB is a moth caterpillar (like many destructive garden pests) that chews its way into the hollow stem of various members of the cucurbit family – yellow squash, zucchini and delicata among others. I have not had a single year where SVB failed to decimate my harvest. By the time you realize the larva has infested your plant, the damage is already so severe that removal is the only practical approach. I always pull up the entire plant, and dispose of it in a lawn and leaf bag to make sure the larva don’t grow up into yet more moths.
If you search on the internet for SVB solutions, many sites recommend barrier methods to prevent the larva from reaching the stem. Another option (that I haven’t tried) is to lance the caterpillar with a needle, or cut open the stem and try to remove the guy. You can also try only planting squash varieties with a solid stem, leaving nowhere for the larvae to tunnel into like butternut and trombetta, but that reduces the variety in your harvest as well. One year I also tried having a second set of plants ready to go out in the garden after the first generation succumbed. The second generation fell even more quickly than the first!
My best hack for squash vine borers?
Grow plants that are so vigorous and so healthy, you are COMPLETELY AND TOTALLY SICK of squash by the time the infestation occurs! You’ll almost feel grateful!
You can accomplish this in several ways. Most important is giving the plants plenty of room to grow. I know planting crops tightly together is all the rage – if you read my garden update, you’ll see I did it as well – but squash need space to spread out both their roots and their leaves and stem. Fertilizing is also a must. I also give the squash a head start by germinating the seeds indoors in early spring, so they are already a healthy size by the time I plant them in the garden.