“How can I determine if a squash plant in my raised bed is just “doing bad,” or if it’s “doing bad because a squash vine borer might have gotten it?” And does one bad squash plant ruin all the rest in the same bed? Nothing seems to be bearing fruit now.” Question from Cat of Horse Shoe, North Carolina.”
Answer: You are in luck! Most of these common questions for squash growers have already been answered for Ask a Garden Expert inquirers. The answers are below. But, you also ask a question has not been addressed. This is about the idea of one squash plant damaging another.
One squash plant can only damage another if it is carrying a disease that can easily be spread. Do you see badly wilting leaves without the evidence of holes or damage on the stems (see the vine borer piece, which shows stem borer images.). Do you see white, dusty mold (powdery nildew) on the leaves or brown or yellow spots? If so, your plants likely have a disease. There are many that attack squash. Some, like powdery mildew, can be managed, while others are deadly. (Click here for a detailed article on all squash diseases.)
Squash Vine Borers
Poor Squash Production
I hope that these tips help!
Black Gold Horticulturist