Row Cover for Pest Control

How does row cover protect plants?

Row cover is a lightweight fabric laid over plants, either directly or on hoops. It lets in light and water but blocks flying insects from landing and laying eggs. Because it works by exclusion, it controls pests without any spray, and it also protects from wind and a little cold.

It is most useful against pests that attack in a predictable season, such as insects that lay eggs on cabbage-family crops, beetles on squash and cucumbers and flies that damage roots. Ask your extension office which pests in your area are well controlled by cover.

Row cover is also a tool for protecting young plants from wind, hail and light frost, so the same fabric can serve more than one purpose across the year.

What kinds of row cover are there?

Covers come in different weights. Lighter fabrics allow more light and air and give little frost protection, and heavier fabrics add several degrees of warmth but let in less light and trap more heat on warm days. Insect netting is a separate product made of fine mesh that lets in more air, which suits warm weather.

Choose the weight for the job: insect exclusion in summer calls for a light cover or netting, and cold protection calls for a heavier one. Check the supplier's description and follow your extension office's guidance.

• Light fabric: insect exclusion with little frost protection.
• Heavy fabric: frost protection but more heat buildup.
• Insect netting: fine mesh for warm-season air flow.
• Hoops: keep fabric off the leaves and give room to grow.

When should you put it on?

Install the cover at sowing or transplanting, before the pest arrives. Cover put on after eggs are laid will trap the pest with the crop and make matters worse. For crops that suffer from soil-borne pests or eggs already in the soil, rotation matters, because covering infested ground simply seals the problem in.

Time the start to the pest's season, using local timing from extension or your own notes on when the pests showed up last year.

Keep a note of what you covered and the date, so that you remember to uncover crops that need pollination and to remove the cover when it is no longer needed.

How do you seal the edges?

The cover is only as good as its edges. Bury them in soil or hold them down with boards, pipes, sandbags or garden pins, leaving no gap where an insect can crawl in. Leave enough slack in the fabric for the plants to grow, since a tight cover tears or lifts as plants grow, and use hoops to hold it up.

Check the cover often and after wind. Patch holes quickly and make sure that no pest was inside when you closed the bed.

What about pollination and heat?

Crops that need insect pollination, such as squash, cucumbers and melons, must be uncovered when flowers open, or hand pollinated. Leafy greens and root crops that are harvested before flowering can stay covered all season.

Under cover, temperatures climb quickly on sunny days. Watch for heat stress, wilting and scorched leaves, and ventilate or remove the cover when it is hot. Use light fabric in summer, and lift the edges on hot afternoons if plants look stressed.

A second look in mid-season helps. Lift an edge and check for pests that got in anyway, and look for signs of fungal disease from trapped humidity.

How do you handle weeds, watering and rotation?

Weeds grow under cover too, so weed before covering and check the bed from time to time. Water passes through most fabric, but check soil moisture by hand under the cover, since rain may not reach plants evenly.

Rotate crops so that the same family does not return to the same bed, and cover with fresh fabric or clean the old fabric between seasons. Pests that overwinter in soil or debris can emerge under cover next year if you leave residue behind.

How do you store and reuse row cover?

After the season, shake off soil, let the fabric dry fully and fold it loosely for storage in a dry place. Sun and storage damage break it down over time, so check for tears and replace worn pieces. A well-cared-for cover can serve several seasons.

Budget for fabric, hoops, pins and your time, and compare the cost with the value of the crop it protects. Write down the dates you covered and uncovered each bed and what you found underneath. Those notes show whether the timing matched the pest and help you adjust the next season.

Last reviewed: November 12, 2026. Written by the Homestead & Small Farm Editorial Team. See our editorial policy.