Learn to grow organic lettuce the green way

Lettuce is a tasty garden staple that comes in many different varieties. We'll teach you how to choose the right type for you, prepare your soil, plant your lettuce, care for your plants, and harvest your bounty.

There are four major types of lettuce:

• True head lettuce features leaves that come together to form a tight head, somewhat like a cabbage.
• Butterhead lettuce also forms a head, but is much looser. Butterhead matures 9 to 10 weeks after sowing.
• Cos lettuce (also called romaine) has tall oval heads that can stand almost 30 centimetres (12 inches) high. Cos lettuce matures 11 - 12 weeks after sowing.  Among cos lettuces, 'Parris Island Cos,' 'Panther MI,' and 'Cimmaron' are favoured varieties.
• Loose-leaf lettuce produces a summer-long harvest of leaves to be cut and replaced by new ones. Leaf lettuce matures 6 - 7 weeks after sowing. Recommended loose-leaf lettuce varieties include 'Grand Rapids,' 'Black-Seeded Simpson,' and the red-leaved 'Red Sails.' 'Esmeralda,' 'Buttercrunch,' 'Bibb,' 'Ithaca,' and 'Deertongue' are green varieties. 'Sangria' has rosy red leaves and good flavour.
• Remember that leaves of all types are edible at any stage of growth. To keep a constant supply of lettuce on your table, sow many times throughout the season.

• To prepare your soil, dig in substantial amounts of organic matter such as compost or rotted manure.
• Loose-leaf lettuce is usually sown directly into the garden as soon as the ground can be worked and is no longer soggy from winter snow and spring rains. Butterhead and cos varieties can be started indoors in flats about six weeks before the ground can be worked, or they can be sown outdoors at the same time as loose-leaf lettuce.
• Sow seeds outdoors 1 centimetre (1/2 inch) deep, 3 centimetres (1 inch) apart, and in rows 30 to 45 centimetres (12 to 18 inches) apart.
• When the seedlings are 5 centimetres (2 inches) high, thin them to 5 centimetres (2 inches) apart. Thin them again when the plants are almost touching one another. You can eat these thinnings.
• You'll probably have to thin the seedlings again to achieve the proper spacing of 15 to 20 centimetres (6 - 8 inches) between plants. Although lettuce will still grow in crowded rows, the heads will be smaller and the plants will have a tendency to bolt.

• Lettuce needs to be fertilized at least once during the growing season. Options include watering the plants with compost tea or a liquid fish fertilizer solution weekly or bi-weekly. Alternatively, you can use compost as a side-dressing alongside the plants a week after planting.
• Weed your lettuce gently and water it frequently. Because the plants need constant moisture, a light mulch can be helpful because it aids in water retention.

• In wet areas, slugs can be problematic. Dispose of them by setting out sunken saucers of stale beer, in which they'll drown themselves, or look for them at night with a flashlight and pick them up by hand. Iron phosphate slug baits are also acceptable for organic gardens.
• Aphids can be controlled by spraying the plants with insecticidal soap.
• Leafhoppers may feed on the undersides of leaves and can be controlled with neem.
• Should pale green worms chew on your lettuce, pick them off by hand or spray with Bacillus thuringiensis.
• Always follow product labels exactly.

• Loose-leaf lettuce is harvested by picking the outer leaves and leaving the centre intact to grow new leaves.
• For butterhead and cos lettuce, cut the entire plant at ground level.
• Harvest frequently. If you leave lettuce unharvested after the heads reach maturity, they begin to lose their nutritive value and flavour.

A good crop of lettuce really completes a garden. Use this guide to grow the fullest, most delicious lettuce around. Your meals will be much better for it.