Row Cover Roundup

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Seasons of the Garden

Row Cover Roundup
Grow rice, pinch peppers and trap bees.

More and more gardeners are setting row covers over their spring plantings to protect them against frost, to boost growing temperatures and even to keep out insects. If you use row covers unwisely, though; you can actually reduce garden productivity. For example, young tomato plants exposed to just a few hours of 95 °F temperatures (not uncommon under plastic on a sunny day) set fruit poorly later on.

Timing—deciding when to put on and remove the plant protectors—can have a big effect on success, but the most important factor is picking the correct material and design for your situation. That's not easy—there are literally dozens of types available.

Writing in American Vegetable Grower, Dr. Doug Sanders, Extension Horticultural Specialist at North Carolina State University, sized up the benefits and drawbacks of the major types of row covers.

Clear polyethylene, hooped: cheap and widely available; quite warm (can become too hot in some cases); labor-intensive installation and removal; poor frost protection.

Clear polyethylene, floating: quite warm (can become too hot in some cases); less labor-intensive than hoop designs; poor frost protection.

Clear polyethylene with slits, hooped or floating: reduced chance of overheating; hard to install.

Perforated clear polyethylene, hooped or floating: more chance of overheating than polyethylene with slits, but easier to install.

Spunbonded polyester, floating: easy installation and removal; low chance of overheating; can be abrasive to plants; expensive.

Spunbonded polypropylene, floating: low chance of overheating; good frost protection; not very abrasive to plants; expensive.

Extruded polypropylene, floating: avail able in very wide widths; easy to install; tears spread easily; poor frost protection.

Photodegradable polyethylene: available with or without vents; no removal necessary; can degrade too slowly or too quickly, depending on weather conditions.

Research Briefs

Grow rice on dry land! M-101 upland rice, being introduced this year by the Southern Exposure Seed Exchange (P.O. Box 158, North Garden, VA 22959; catalogue $3), can be grown without flooding the soil. In fact, it's said to require less water than corn. Upland rice has shown no serious insect or disease problems and has been grown from Florida to Albany, New York. Yields average about five pounds of grain per 100 square feet. The hitch? You have to dehusk the grain (SSE is researching small-scale dehusking methods).