Parts of my healthy-looking squash plants suddenly wilted and died. What caused that?
A sudden wilting of squash-type vines is often caused by the larvae of the squash vine borer moth which bores into fleshy squash stems effectively killing that part of the vine. Floating row cover is a good barrier method for early control. This needs to be removed for pollinators once blooms open. For chemical controls, check with your local garden center.
