Lettuce

Lettuce is generally divided into three categories: (1) tight, crisp, nearly white head lettuce with a cabbage-like head; (Little Gem Butterhead, Buttercrunch) (2) loose, so-called leaf lettuce, where although there is a head, it is looser, and with many more outer green leaves; (Salad Bowl Mix) (3) Romaine lettuce, which is cylindric, has long, relatively loose leaves and so forms a head which sometimes needs to be tied up (Freckles Romaine).

Of the three categories, the first is the most difficult to grow; the second is easy to grow and a good choice for beginners, and the third is also easy to grow and can stand up to summer heat. Lettuce is a cool season crop (except Romaine) and is commonly planted in early spring and late summer. Most lettuce varieties must mature before the weather gets warm. Midsummer heat, more than other things will cause lettuce to flower. That ruins the chance of heading because the tall flower stalk is forced up through what should be the head. However, there are bolt-resistant, heat-tolerant varieties for growing in warm weather. Most lettuce seed packets will give the heat tolerance of the variety or cultivar. Sow lettuce seeds indoors 4 to 6 weeks before the average last frost date in spring; transplant seedlings to the garden when they are about 4 inches tall. Direct sow lettuce in the garden in early spring 4 weeks before the average last frost date when the soil temperature is at least 35°F. Sow lettuce again when the weather cools in late summer or fall. Where the weather stays mild or warm most of the year, grow bolt-resistant, heat-tolerant varieties. In regions where the weather gets cold in winter, time for lettuce planting to bring the crop to harvest before the first fall frost or grow lettuce through the winter under a plastic tunnel or cold frame. Lettuce will be ready for harvest 65 to 80 days after sowing depending on the variety. In hot summer regions, time lettuce planting so that the harvest comes in late spring or in autumn.

Where to Grow Lettuce

• Grow lettuce in full sun or partial shade. Use shade cloth to protect lettuce from very warm or hot weather.
• Lettuce prefers well-worked, well-drained soil that is rich in organic matter and moisture retentive. Sandy loam is the best choice of soil to grow lettuce.
• Add 4 inches or more of aged compost or commercial organic planting mix to planting beds in advance of planting. Turn the soil to 6 inches deep.
• Lettuce prefers a soil pH of 6.0 to 6.8. Lettuce soil should not be acid. If a soil test find that the soil is acid, it should be limed.
• More important than texture is soil moisture.

Lettuce Planting Times Through the Year

• Lettuce is a cool-season crop that must come to harvest before the weather gets warm.
• Sowing lettuce seed should be timed so that they are transplanted to the garden just as soon as the ground can be worked. You need not wait for the last frost of spring in order to set out the seedlings, because, especially in their early stages with will easily endure several degrees of light frost.
• Sow lettuce seed indoors 4 to 6 weeks before you plan to set transplants in the garden—commonly 4 to 6 weeks before the last frost in spring. You can even begin sooner if you like, up to 10 weeks before the last frost.
• Transplant seedlings to the garden when they are about 4 inches tall but not before night temperatures remain above 30°F.
• Direct sow lettuce in the garden when the soil temperature is at least 35°F Lettuce seed will not germinate in soil cooler than 35°F.
• Sow lettuce every three weeks for a continuous harvest. As temperatures warm sow bolt-resistant, heat-tolerant varieties.
• Eight weeks before the first expected frost in autumn, switch back to cool-weather lettuce varieties.
• In mild-winter regions, grow lettuce from autumn through winter into spring. Sow succession crops every three weeks through the winter.
• Lettuce will be ready for harvest 65 to 80 days after sowing depending on the variety.

Starting Lettuce Plants Indoors

• Sow lettuce seeds ¼ inch deep; cover with finely listed soil. Sow bolt-resistant lettuce ½ inch deep.
• Seeds can be broadcast in flats or sown in tiny drills in flats.
• To prevent soil crusting, sprinkle finely sifted compost or organic potting soil over the seeds.
• Place seeded flats under a grow light or in a bright window. Turn flats of young plants every couple of days for even growth.
• In a few days, the plant will be up and as soon as they are 2 inches high with true leaves; they must be pricked-out and spaced about 2 inches in each way. A second and third spacing is advised.
• For Self Sufficiency: Plant 6 to 10 heads per person in the household.

Planting Lettuce Outdoors

• Young lettuce seedlings are best set out in the garden on an overcast day; in any case, thy should be watered until they recover from the move.
• Direct sow lettuce in the garden after indoor started plants have been set out.
• Lettuce seeds sown outdoors can be broadcast or in very shallow drills; in either case covered very lightly with the finest soil.
• Slightly tamp the soil and water it with a fine mist like spray (a hose spray without a fine nozzle will wash out the seeds).
• The seeds will come up too thick for permanent spacing.
• Outdoor sown seed will provide a good crops aft there indoor started plants have been harvested.
• Succession planting can follow beginning about 12 days after the first outdoor sowing.

Thinning and Spacing Lettuce in the Garden

• Lettuce must be thinned; lettuce that is too crowded will bolt. Thin to 6 loose leaf plants per square foot, 1 heading lettuce plant per square foot.
• Transplant rooted thinnings to another row or spot; transplanted lettuce will be set back a couple of weeks but it will come to harvest.

Fall Crop Lettuce

• For a fall lettuce crop, follow the same procedure for the early crop of indoor seedlings, except that the flats are put outdoors in a cool, shaded place.
• Young plants should be ready to set out about August 15 

Companion Plants for Lettuce

• Grow lettuce with carrots, cucumbers, radishes, strawberries, and herbs including cilantro.

Watering Lettuce

• Plenty of soil moisture will help induce rapid growth; slow-growing lettuce will not taste good.
• Lettuce has a shallow root system; do not let plants dry out. Keep the garden bed evenly moist but not soggy.

Feeding Lettuce

• Lettuce grows best in soil rich in plant food.
• Add aged manure to the lettuce planting bed in advance of planting. Aged manure adds much huus to the soil and thus heightens its moisture-holding capacity as well as enriching it. Turn the manure into the soil so that there is a fine tilth.
• Additionally, feed lettuce with compost tea or manure tea every two weeks throughout the season.
• You can also feed lettuce with aged compost or a commercial organic planting mix added as a mulch or side dressing around plants.

Harvesting and Storing Lettuce

• For the best flavor and crisp texture pick lettuce when you need it and use fresh lettuce right away.
• For loose-leaf varieties, cut outer leaves on a cut-and-come-again basis and allow inner leaves to remain and develop. You can harvest the whole plant at once by cutting it off at ground level.
• Harvest crisphead, Romaine, and butterhead lettuce when the heads are firm and mature. You can lift the entire plant or cut heads at the crown just above soil line. Where heads are cut at the crown, smaller leaves will grow for a second harvest.