I don't understand what you're trying to do. The adult squash vine borer is a flying insect. It will find your plants whatever you plant them in, or put under them. I use black plastic under my zucchini and caught adult borers off my plants last year.

I sprayed regularly and had no problems all season.

None of what you list will make any difference unless you grow them inside under cover where the moths can't get to the plants to lay their eggs.

That is what makes using floating row covers so effective at preventing them - the moths can't get to the plants.

Dave

I just read recently in a gardening book that if you use transplants instead of growing from seeds you have a better chance of not getting them. I've never heard this before, but I'm going to try it this year.

yes, sorry. this was in addition to cover. The adult emerges from the thing in the soil. Trying to get to the source.

True but the moth just emerging doesn't do the damage. She has to fly off and mate before settling into egg laying.

But I can see where plastic mulch would help keep them from emerging - organic mulches wouldn't even slow them down.

Dave

Floating row cover doesn't work - the adult moths will just get under the cover. Cover needs to be secured all around the plant until flowering. Then, you either have to pull the cover or hand-pollinate every flower, pulling up the cover and then securing it again.

The best way to deal with SVB takes years. First, always get rid of any vines you see already attacked by borers. You need to keep on your plants faithfully to make sure you don't miss any. Over time, that will keep the larvae from going down into the soil and pupating until next year.

The next year you can try cover, but I get my attacks after flowering begins, so I don't bother. I don't have time to deal with taking cover on and off. After flowering has begun, I start a regular schedule of spraying, about once a week, or after a good rain. Two years ago, I lost a plant to borers. Last year, none. Adults will fly in from other people's property, but if you keep your own soil clean, you're one step ahead. Covering the soil with plastic might work except the adults come up out of the soil and find the hole you put your plant through.

Some people don't grow any susceptible vines for a year or two.