Row covers are sheets of lightweight fabric laid over a crop, usually held up by hoops, to protect it from frost, wind, heavy rain and insect pests. They are one of the cheapest and most useful tools in the vegetable garden: a row cover can bring a crop forward by weeks in spring, protect it from a late frost, keep carrot fly and cabbage white butterflies away, and extend the season into autumn. They need no electricity, they are easy to fit, and a single cover can be reused for several seasons if it is looked after. This guide covers the types of row cover, how to fit them, and when to use and remove them.
There are two main types. Fleece row covers, also called horticultural fleece, are made from a lightweight spun fabric that lets light and water through but holds in warmth and keeps frost off the leaves. Mesh or insect-proof row covers are made from a fine net that keeps insects out while letting light, air and water through, but they give little frost protection. Some covers combine both jobs, but in general, use fleece for frost and warmth, and mesh for pest protection. Both types are sold in rolls or pre-cut lengths, and they are light enough to lay over a crop without crushing it, though hoops are better for taller crops. Our frost cloth guide covers the lightest frost protection, and cloches for plants covers individual plant covers.
Fitting a row cover
Lay the cover over the crop and fix the edges firmly, because a loose cover flaps in wind, damages leaves, and lets cold air and insects in underneath. The usual method is to push wire or plastic hoops into the ground over the row, drape the cover over the hoops, and bury the edges in soil or weigh them down with bricks, stones or lengths of timber. Hoops keep the fabric off the leaves, which prevents frost damage where the fabric touches the plant and gives the crop room to grow. For low crops such as lettuce and radishes, the cover can be laid directly on the plants, but check that it does not sit heavily on young seedlings. Leave enough slack in the cover for the crop to grow, and check it every few days to make sure it has not slipped or torn.
Do not leave a cover on permanently. Lift it on mild days to check the crop, to water if the soil is dry, and to let in fresh air, because a cover that is never lifted can become damp and encourage mould and slugs. In spring, remove the cover once the weather warms up and the frost risk has passed, so the crop gets full sun and pollinators can reach it. Crops that need insect pollination, such as courgettes, squash and beans, must have their covers removed when they flower, or the flowers will not set fruit. Use the frost date calculator to check your local frost dates, and our planting calendar pages such as zone 5 lettuce for timing by zone.
What row covers protect against
Frost is the main job of a fleece row cover. A cover over a row of lettuce, peas, potatoes or early carrots can protect them from a light frost that would damage unprotected plants, and it can bring spring sowings forward by weeks. Wind is the second job: a cover shelters young plants from drying wind and from wind-blown soil, which helps them establish faster. Heavy rain is the third: a cover breaks the force of rain, which protects young seedlings from being battered and stops soil splashing onto leaves, which can spread disease. Pests are the fourth job, and here a fine mesh cover is the right tool: it keeps carrot fly off carrots, cabbage white butterflies off brassicas, and flea beetles off radishes and turnips, without any spray. For pest protection, the cover must be fitted before the pest arrives and sealed at the edges, because a single gap lets insects in and then traps them inside with the crop. If you are unsure which pest is affecting a crop, the pest identifier helper can help.
Crops that suit row covers
Row covers suit almost any low vegetable crop. Lettuce, spinach, radishes, spring onions, carrots, peas, beans, brassicas such as cabbage, broccoli and kale, and early potatoes all benefit from a cover in spring. Salad leaves and herbs grown under a cover in autumn last weeks longer than unprotected plants. Flowers such as sweet peas and early annuals also benefit. Tall crops such as sweetcorn and tomatoes are too tall for a standard row cover once they grow, though a cover can protect young tomato plants for a few weeks after planting out. Our growing guides for growing lettuce, growing carrots, growing peas and growing kale give crop-by-crop detail. If you are unsure what will grow under cover in your area, check your local extension service for advice.
Care, storage and reuse
A row cover that is looked after lasts several seasons. Remove it carefully, shake off soil, let it dry fully before folding it away, and store it in a dry place out of direct sun, because sunlight degrades the fabric over time. Repair small tears with tape or by stitching, and replace a cover when it becomes thin, torn or so brittle that it falls apart. Do not leave a fleece cover on a crop in hot summer weather, because it can overheat the plants underneath, and do not leave any cover on so long that the crop outgrows it and pushes the fabric up. Check under the cover regularly for slugs, which love the damp, sheltered conditions — our slug control guide covers organic-first methods.
Row covers through the year
In early spring, fleece covers protect early sowings and young plants from frost and wind. In late spring, mesh covers protect brassicas and carrots from insect pests. In summer, mesh covers stay on pest-prone crops, while fleece covers come off as the weather warms. In autumn, fleece covers go back on salads and herbs to extend the season, and they can keep a crop going for weeks after the first frosts. In winter, a fleece cover over hardy salads in a sheltered spot can keep them pickable through the coldest months, especially combined with a cold frame. A row cover is a small investment that repays itself many times over in earlier crops, fewer losses and less pest damage.
Common mistakes
The most common row cover mistakes are leaving the edges unsealed so cold air and insects get in, leaving a cover on too long so the crop overheats or outgrows it, leaving a cover on a flowering crop that needs pollinators, using fleece when mesh is needed for pests, and using mesh when fleece is needed for frost. Another is fitting a cover after the pest has already arrived, which traps the pest inside with the crop. The fixes are simple: fit the cover early, seal the edges, lift it regularly to check the crop, remove it when flowers need pollinators or the weather warms up, and choose the right type for the job.
Frequently asked questions
What is the difference between fleece and mesh row covers?
Fleece is a lightweight spun fabric that holds in warmth and protects against frost, wind and heavy rain. Mesh is a fine net that keeps insects out while letting light, air and water through, but it gives little frost protection. Use fleece for warmth and frost, and mesh for pest protection.
Do row covers need hoops?
Hoops are better for most crops, because they keep the fabric off the leaves, prevent frost damage where fabric touches the plant, and give the crop room to grow. Low crops such as lettuce and radishes can have a cover laid directly on them, but hoops are still preferable, especially for fleece in frosty weather.
Will a row cover stop carrot fly?
A fine mesh cover fitted before carrot fly arrives, with the edges sealed, is one of the most reliable ways to protect carrots from carrot fly, because the fly cannot reach the plants to lay its eggs. The cover must be sealed at the edges, and it must be fitted before the pest arrives — a cover fitted after the fly is already there traps it inside.
When should I remove a row cover?
Remove a fleece cover once the frost risk has passed and the weather is warm, so the crop gets full sun. Remove any cover when a crop that needs insect pollination, such as courgettes, squash or beans, starts to flower. Lift covers regularly through the season to check the crop, water if needed, and let in fresh air.
Can I reuse a row cover?
Yes, if you look after it. Remove it carefully, shake off soil, let it dry fully before folding it away, and store it dry and out of direct sun. Repair small tears, and replace a cover when it becomes thin, torn or brittle. A well-cared-for cover can last several seasons.