OK, I know this is an old thread, but my squash plants are getting about 8 inches tall and I would like to actually get some squash to eat this year (i.e., keep squash vine borers from killing my plants).
By the way, I know that I must be in a minority, but I have no aversion to commercial pesticides. I don't care one bit about "organic" techniques.
Someone above posted a link to
https://extension.umn.edu/yard-and-g...sh-vine-borers
I am posting the part regarding the use of pesticides for my own future reference and for any others who don't mind using such products:
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Using pesticides
If pesticides are needed, spray or dust the stems at their base.
Start treatments when vines begin to run (or the last week of June or early July for non-vining varieties) or when the first adult borers are detected.
Repeat in 7-10 days.
Two applications help manage most squash vine borer adults.
For more thorough coverage, continue treatments at 7-10 day intervals until the end of July. Common names of active ingredients effective against squash vine borers are: carbaryl, permethrin, bifenthrin and esfenvalerate.
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Always follow label instructions.