Row covers accelerate growth and protect crops from frost in fall.

Row covers are gauze-like blankets made of spunbonded polyester. They are used to promote growth and protect plants from frost. These remarkable covers also keep pests out but allow rain to pass through.

Row covers are categorized by weight (0.3 to 2.5 oz/sq yd). The lightest covers are used in spring to control insects on potatoes and cool-season crops. For example, they prevent damage from flea beetles and cabbage moths.

Medium weight (approx 0.5 oz/sq yd) can be used later this summer for frost protection. We use this in growing spinach and turnips in fall. They trap heat, accelerate growth and give you four degrees of frost protection. These covers can be used with or without hoops for support.

Hoops can be purchased or you can make your own by using #9 galvanized steel wire. Cut them into 65- to 72-inch segments and insert them every four feet down the bed. PVC pipes can be used as well.

Hoops are not needed for cool-season crops. Lay the fabric loosely over the garden bed. Secure the edges with soil, rocks or sandbags. The fabric is so light the plants will lift it as they grow. Used in this manner, the fabric is referred to as a floating row cover. A six-foot-wide fabric will cover a three-foot-wide bed.

Heavier row covers, called frost blankets, can provide eight degrees of protection. They are used at night, often to protect warm-season crops. Hoops are used for these heavy covers.

I realize the drought is on our minds now, but the long-term forecast for this fall is more favorable. We can extend our season and grow more vegetables this fall by using row covers. 

Written by Tom Kalb, Extension Horticulturist, North Dakota State University. Published in the NDSU Yard & Garden Report, July 15, 2017. 
The photo was made available under a Creative Commons license specified by the photographer: Jim Sincock. 

Sources:
Johnny’s Selected Seeds. 2017. Seed catalog.
Parker, J., C. Miles, T. Murray and W. Snyder. 2012. How to install a floating row cover. Washington State University; Pullman.
Penn State Extension. 2017. Plasticulture: Row covers. Pennsylvania State University: State College.