Protect your crops

Protected cropping is the single biggest trend in horticulture today. High tunnels, low tunnels, row covers, and mulches can be used to protect crops from bad weather. Protected cropping can extend the season for months, while increasing yields and improving quality of vegetables, fruits, herbs, and flowers.

The ultimate tool in protected cropping is a high tunnel (also called a hoophouse), which is an inexpensive, unheated greenhouse erected right in the field. Hoophouses are quickly becoming an essential component of most produce and flower farms. A single layer of greenhouse poly over metal or PVC hoops, tall enough to walk into, provides an amazingly different growing environment. Hoophouses don't need electricity or heating systems, although some growers do add them to extend the season even further. In general, though, roll-up or roll-down sides are used to ventilate a hoophouse, and the sun does the work of heating it.

Some of the crops that are commonly grown in a hoophouse include lettuce and greens early and late in the year; strawberries in spring; raspberries and tomatoes in summer; and spinach and other cold-hardy vegetables over the winter. Many other crops will benefit from the protection, depending on regional variations. With careful crop selection, a hoophouse can be the most productive land on a farm.

Another protected cropping tool is a low tunnel. Low tunnels are made of small metal or PVC hoops pushed into the soil over a bed of crops, and covered with spun-bonded polypropylene row covers. Low tunnels warm the soil and protect plants from frost and wind. They can be used early in spring for cool-weather crops, in late spring to give a head start to warm-weather crops such as tomatoes and peppers, and again in fall to keep cool-weather vegetables growing longer. They also are useful for protecting crops from predictable insect pests such as flea beetles and cabbage moths.

Using a low tunnel within a high tunnel is useful in cold climates to keep the soil from freezing until the dead of winter. Although plants stop growing when the days are short in mid-winter, cold-hardy vegetables such as carrots and spinach can be harvested nearly all winter in this system.

Row cover alone can be pulled over crops to save them from untimely frosts. Late and early frosts are often one-night affairs; protecting against those small dips in temperatures can keep crops alive for several additional weeks of good growing conditions. Most growers keep a supply of row cover on hand for just such emergencies.

Plastic or paper mulches are another component of protected cropping systems. Black solar mulch warms cold soil; white-on-black mulch keeps soil cool. Biodegradable and paper mulches eliminate the need to take them up at season's end. All types suppress weeds, reducing labor.

By employing some or all of these protected cropping strategies, growers can take some of the risk out of farming.

Lynn Byczynski is the editor of Growing for Market and the publisher of The Hoophouse Handbook.

Articles by Lynn Byczynski

About the author:

Lynn Byczynski was growing organic vegetables and cut flowers for market when she decided to create a magazine that would help market gardeners nationwide share experiences and information. Her first issue of Growing for Market appeared in January 1992 and it has been published continuously since then. GFM is renowned in the market gardening world for realistic articles that give growers practical, how-to information about growing and selling produce and flowers. Lynn is now partnering with Johnny's to provide similarly useful information for the website and other publications. Lynn, her husband Dan Nagengast, and their two children have grown vegetables and cut flowers since 1988, selling through a CSA, at farmers markets, to chefs, grocery stores, and florists. They currently grow cut flowers and hoophouse tomatoes on about 2 acres of their 20-acre farm near Lawrence, Kansas. Lynn is also the author of several books about market farming: The Flower Farmer: An Organic Grower's Guide to Raising and Selling Cut Flowers ; The Hoophouse Handbook ; Market Farming Success