Issue: September 2004

Extend the Growing Season for Vegetables

To enjoy fresh vegetables in fall and winter, many gardeners freeze, can or dry their produce. But growers can extend the season by storing some root crops directly in the soil, and by planting cold-hardy vegetables in September.

The flavor of parsnips and carrots will actually improve if left in the ground during winter. As soils cool, starches in the roots are converted to sugars, making parsnips and carrots sweeter. Parsnip roots can also be dug and stored in moist sand outdoors during the winter.

Potatoes as well can be stored in the ground for winter use. After vines turn yellow and die back in the fall, remove vines at ground level with a pair of hand shears. Cover the area with two to three inches of clean straw to keep soil from freezing. When digging potatoes for Thanksgiving, remove straw only from the area needed to supply family and dinner guests. Be sure to dig up remaining tubers early next spring before soils begin to warm and tubers begin to sprout.

Growers can also extend the season by planting leaf lettuce and spinach in early September. High soil temperatures in September can inhibit germination of some varieties, but frequent, light irrigation during the hot part of the day will cool the soil. As soils naturally cool later in the month, germination will improve.

Cover spinach and leaf lettuce in late September or early October with a row cover. Use spunbonded polypropylene row covers that permit air to move underneath. The covers will raise soil temperatures two to six degrees at night. During warm daytime hours, the air circulating underneath will avoid the need to vent rows. The covers can be supported with wire hoops or left to float over the plant like a loose blanket. In both cases, cover the edges of the fabric with soil to keep it from blowing away. Spinach will overwinter in most areas of the state and can be harvested again next spring.

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For more gardening information, visit New Mexico State University's Cooperative Extension Service publications world wide web site at

George W. Dickerson, Ph.D., is is a horticulturist with New Mexico State University's Cooperative Extension Service. New Mexico State University is an equal opportunity/affirmative action employer and educator.

Also Please join us on Southwest Yard & Garden, a weekly garden program made for gardeners in the Southwest on:
KNME-TV Albuquerque at 9:30 p.m. Saturdays,
KENW-TV Portales at 10 a.m. Saturdays,
and KRWG-TV Las Cruces at 11:30 a.m. Saturdays (repeated at 1 p.m. Thursdays.)