Row Covers: The No-Spray Way to Protect Plants

Lightweight fabric row covers are an easy way to protect your crops from insects and critters, and extend the season.


| February/March 2008



Woman Installing Row Covers

The best edge-anchoring plan involves attaching the row cover’s long edges to bamboo poles, straight saplings or pieces of 2-by-2 lumber. Use a stapler to make the hems and then slide in the poles. This makes it easy to lift the covers off for weeding and to allow pollination.  


Illustration by Elayne Sears

In many organic gardeners’ storage sheds lurk what look like stashes of dirty bed linens. These are actually sheets of reusable fabric row covers, which serve as barriers between plants and those creatures that would destroy them. Without ever picking up a sprayer, you can use row covers to eliminate problem insects, and prevent browsing by rabbits and deer, too. When combined with a weed-suppressing mulch (such as straw or grass clippings spread over wet newspapers), row covers often increase yields of peppers, strawberries and cucumber-family crops by more than a third.

Unlike plastic, which blocks rain and quickly heats up in the sun, the zillions of tiny holes in fabric row covers let rain in and heat out. Perforated plastic row covers do vent out hot air through thousands of holes or slits, but they are much less durable than breathable fabric row covers, which can be reused for several years and serve multiple purposes. With fabric row covers in place over your spring salad patch, you can stop worrying about biting winds and hungry rabbits. In summer, you can sleep easy knowing your melons are safe from four- and six-legged saboteurs that sneak in at night.

Lessons In Light

Garden row covers come in different weights, with thick versions such as Agribon 50 or various “frost blankets” providing up to 8 degrees of frost protection. The density needed to retain heat comes at a cost, however, because heavyweight covers admit only 50 percent of available light. This level of light deprivation nearly offsets these covers’ insulating benefit, though thick covers are great to use in late winter to promote heavy, early production of strawberries and fall-bearing raspberries such as the ‘Heritage’ variety.

Midweight row covers, such as Agribon 19, Reemay and Covertan 17, admit 75 percent to 85 percent of available light. They also provide 2 to 4 degrees of frost protection and excellent buffering of strong winds. The fibers in midweight row covers are dense enough to provide multiseason durability, but still porous enough to admit rain and ventilate themselves on sunny days. Should a serious cold snap hit, you can simply add a sheet of plastic or throw an old blanket on top of the row cover.

As the weather cools in the fall, midweight row covers are great for wrapping around caged tomatoes or peppers that are heavy with ripening fruits, or you can use them to keep aphids, leaf miners and flea beetles from finding your leafy greens.

Very lightweight row covers give little or no frost protection, but they also retain very little heat while admitting 95 percent of available light. These covers are standard equipment for excluding squash bugs, cucumber beetles and squash vine borers from young squash, cucumbers and pumpkins, or for keeping cabbageworms and root maggots from finding your broccoli. Row covers do need to be left off some plants to allow for pollination. Most vegetables that produce flowers before they make a crop, such as squash, cucumbers, tomatoes and peppers, require repeated visits from insects to spread pollen from flower to flower. Root crops and leafy greens need no pollination, so they can be grown under covers until they are ready to pick. Last August, a featherweight row cover held in place with clothespins spooked the family of deer that had taken to eating my ripening grapes for their breakfast.

jaweebs
4/26/2016 6:11:35 PM

Could someone please post which veggie plants need the bees for pollination and approx when should row covers be removed---first time user after feeding all the evil insects last year with my beloved garden!!! Would so appreciate !!!


labgirl1
7/24/2009 8:02:04 AM

I've used old curtain sheers for years. I look for them all the time at resale stores. I put sheers over opened out tomato cages to cover my collards, kale, and other assorted greens. I use them to protect from early frosts in the fall and late frosts in the spring. I cover my blueberry bushes to keep the birds from eating all of them. I've tried the commercial row covers but still keep coming back to the curtain sheers.


garden guru
2/4/2008 12:32:11 PM

My own experiences with light and medium weight row covers such as Reemay, have also been pretty favorable, but not in all cases. One clear winner was found in protecting a delectable crop of blackberries from pesky birds. Edible greens were fairly well protected from ravenous bugs as well. But without question, one size doesn't fit all. Sun-loving peppers and tomatoes do much better without the intrusion of light-filtering, moisture-retaining fabric. Additionally, these fabrics will certainly NOT stop hungry deer or clever rabbits from ravaging your crops. As part of an integrated solution, row cover works well when treated with a natural eco-safe spray such as Liquid Fence Deer & Rabbit Repellent – or when used in a fenced-protected garden – but absolutely not alone! There is one other VERY important thing for readers to remember: this very same "protective" fabric will keep beneficial insects OUT, including those ever-loving wonderful bees!






mother earth news fair

MOTHER EARTH NEWS FAIR

Oct. 21-22, 2017
Topeka, KS.

More than 150 workshops, great deals from more than 200 exhibitors, off-stage demos, inspirational keynotes, and great food!

LEARN MORE