   Fresh Lettuce from the Garden - February 23, 2000 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Lettuce is easy to grow and makes an excellent addition to any meal. Apart from crisp salads, it is tasty on sandwiches, in Chinese soups and stir frys, in tacos, and as a garnish to liven up almost any meal. Lettuce, especially the dark green and red varieties, has vitamins and minerals including vitamins A and C, iron, folic acid, and calcium, although storage decreases Vitamin C content after a few days. Iceberg or Acrisphead@ lettuce is the most common commercial variety, but consumer demand has increased availability of many other lettuce varieties at supermarkets. Bibb (butterhead), romaine, and red and green leaf lettuces are available year round. ABaby@ lettuce mixes are packaged in sealed plastic bags and sometimes sold in bulk. In winter, most of our lettuce comes from Yuma and the Imperial Valley. In summer, much of our lettuce is grown in the Salinas Valley on the central coast of California. During fall, winter, and spring there is no reason lettuce cannot come right from your own backyard garden. Iceberg lettuce is not heat tolerant and needs about 75 days to mature. Some cultivars are being developed that tolerate the heat, but personally, I would rather grow (and eat) other varieties. Conversely, leaf lettuces mature in 45 days, are more heat tolerant, and are relatively easy to grow in home garden situations. There are hundreds of varieties including Black-Seeded Simpson, Oak Leaf, Grand Rapids, Ruby Red, and Red Sails. Mixes of several varieties are often available in a single packet. These are really fun to grow and observe the differing varieties mature. Bibb lettuce was developed by Kentuckian John J. Bibb and is often served at Kentucky Derby breakfasts. It produces a loose, soft head, with soft, waxy (buttery) inner leaves. Think of it as an intermediate between iceberg and leaf lettuces with respect to days to maturity, texture, and taste. Bibb lettuce varieties include Big Boston, Bibb, and Butter Crunch. Romaine (cos) lettuce produces an elongated head of stiff, upright leaves ready about 60 days from planting. How could we have a Caesar salad without this European staple? In addition to green cultivars, red cultivars Rosalita and Rouge d 'Hiver are available from mail order sources. Lettuce germinates and grows best at low temperatures and will withstand a moderate freeze. Because of this, it can be planted as soon as the ground can be worked in the spring. It also does well as a fall crop and can be planted in August. However, high soil temperatures in the summer can inhibit germination. You can improve germination of cool-season plants in summer by shading newly planted seed with a board or light covering of mulch. For those that like specifics, head lettuce seed can be sown outdoors between 2/15 and 3/15 (spring planting) or 7/15 and 8/15 (fall planting). Leaf lettuce seed can be sown outdoors between 3/1 and 4/15 (spring planting) or 7/15 and 9/1 (fall planting).One problem many gardeners have is too much lettuce at one time. Production time can be extended by making a series of small plantings 10 to 15 days apart. With the use of floating rowcovers and/or coldframes, salad greens can be planted in late August and early September and protected from hard freezes in the fall. Hot weather causes the milky sap to become bitter. High temperatures and long day lengths also cause lettuce plants to "bolt" or flower and go to seed. Bibb and iceberg varieties are especially sensitive to bolting. Lettuce seed should be sown thinly in rows or wide row bands about 1 2 to 2 feet apart and covered with not more than one-half inch of fine soil. Keep the soil moist for 10-14 days for good germination. Wide-row planting will use your garden space more efficiently than traditional narrow rows. It is important to thin the plants to allow good air circulation between the plants. Thinning also will help prevent foliar diseases. Leaf lettuce should be thinned to about 3" between plants in all directions. Allow 6 to 8" between Bibb plants and 10-12" between iceberg and Romaine lettuce plants. An average packet of seed will sow 50 feet. Now you are ready for planting your spring greens and enjoy some fresh salads. Learn about upcoming fruit tree pruning workshops offered by Cooperative Extension at: http://ag.arizona.edu/yavapai/. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 or E-mail us at mgardener@kachina.net and be sure to include your address and phone number. |