So what you are talking about is called 'mulching' your ground rather than covering your plants.

Mulching the ground is always a good idea although plastic isn't considered the ideal. Black permeable landscape fabric (it isn't plain black plastic) is used in landscaping and in gardens to warm the soil for planting early, to protect some crops like berries and other low growing crops from dirt contact and dirt splash, to prevent the kind of damage you have described, and to help retain soil moisture. To hold it in place most cover the edges with several inches of soil, use bricks or rocks, landscape fabric staples sold for that purpose, or another type of mulch on top of it.

On the other hand organic mulches are more recommended. Things like thick layers of straw, hay, shredded leaves, grass clippings, compost, etc. work just as well as the plastic and doesn't have the drawbacks of the plastic.

If you type 'mulch' into the search bar here you'll find lots of discussions about it.

Dave

Concur with Dave.... Black plastic works great for me on strawberries and on canteloupe and watermelon. I use bricks to keep the black plastic in place. But for mulching everything else, I agree with Dave's recommended organic mulch approach. I use bagged leaves that were collected during the Fall.