Growing Lettuce

From early spring through until the frosts, lettuce will provide salad vegetables. To extend the season even further you can grow lettuce in a greenhouse.

For economy in growing a wide variety of lettuce, grow them from seed. If time and space make this unsuitable, you can buy seedling lettuce plants from any local plant nurseries. If you look carefully, some suppliers are now offering mixed trays of seedlings, and this will allow you more variety.

Soil
Lettuce needs a good, rich soil to do well. Grow in soil that was manured for a prior crop - it will be too rich if manured immediately before planting. If the soil pH is below 6 add some lime. Poor or compacted soil will not produce a good crop, and raised bed culture is ideal.

When planting in the garden plant in rows 15 to 20cm apart, in raised beds and containers you can plant in blocks.

Site
A sunny or partially shaded site is best you can also use home greenhouse.

Growing from seed
Lettuce seeds germinate better in cool soils and will become dormant in soil temperature of 25C and above. You can begin to sow seeds of cold tolerant varieties about four weeks before the last expected frosts. Sprinkle the seeds onto the top of the soil, either directly into the vegetable garden or in a starting tray, and cover lightly with soil. Dampen the soil and remember to keep the new seedlings and later the plants moist- lettuce needs moisture throughout the growing season.

As the seedlings develop you need to thin them. Starts when they are about 2” to 3” tall, by thinning out the largest plants you have an instant salad. Continue to thin until there is 6” to 12”, depending on variety, between the plants.

Sow seeds every two to three weeks to provide for a succession of salad crops.

Seedlings
Plant out about 6” to 12” apart, depending on variety. Ensure the seedlings are kept moist and don't scorch. (An old gardener’s trick is to lay wet newspapers alongside the plants to keep the soil moist. Watch out for slugs and snails, as they love moist conditions as much as your precious lettuce plants do!)

Harvest
Pick lettuce at 45 to 50 days. Pick the outside leaves off the plant, it will continue to grow, or cut the plant 2” above the base. Plants that are left after they have formed a firm heart will 'bolt' and become bitter.

Cultivation options
Lettuce is an ideal plant to grow in containers, sow seeds of plant seedlings into a large pot, and place it in a sunny position. So many lettuces available now have frilly or colored leaves- they make a great feature on the terrace. Watch carefully for signs of heat stress; container plants dry our much more quickly than those in the garden.

Lettuce grown in the garden is generally best grown in rows, 6” to 8” apart, depending on variety. In raised beds you can plant lettuces in blocks.