Here are the major types of products you can buy and how to use them to your best advantage.
1. Floating Row Covers
This translucent, white, porous polyester fabric acts as an insect barrier, while letting in up to 80 percent of the available light. You can buy either lightweight or heavyweight types—you’ll want to use the lighter one for controlling pests in summer, because it will keep out bugs without cooking your plants. The heavier reportedly traps more warmth and so is better for season extending.
The material is sold by the yard, generally in rolls 4 to 8 feet wide. You cut it to the length you need, then drape it over metal hoops, attach it to wooden supporting frames, wrap it around wire tomato cages, or simply lay it directly on your crops like a blanket. Important: You must secure the edges of the row cover with soil, U-shaped pins (either commercial or homemade ones crafted from wire coat hangers), boards, bricks, or rocks.
Use floating row covers as temporary barriers to get plants past critical stages, such as when they are seedlings or while the pest you are deterring is most active. Of course, you could keep the crop covered for its entire life span, although this isn't a good option for crops that require insect pollination.
Pests controlled: Row covers are especially useful against mobile pests, including cabbage moths (imported cabbageworms), Colorado potato beetles, most aphids, Mexican bean beetles, flea beetles, squash bugs, and tomato hornworms. Combine row covers with crop rotation if you’re dealing with pests that overwinter in the soil.