At a glance...
Botanical name: Lactuca sativa
Origins: Near East and countries bordering the Mediterranean Sea
First cultivated: 2600BC as a food crop, possible earlier use as a medicinal plant
Types: Hundreds of varieties are split between 5 main groups:
- Butterhead – quick to mature with a loose heart and soft leaves
- Cos/Romaine - long, upright heads, essential for a true Caesar salad
- Crisphead/Iceberg – large crisp heads with solid hearts and few outer leaves
- Loose leaf – loosely bunched leaves, mainly used for salads
- Summer crisp/Batavian – midway between crisphead and loose leaf types
Skill level: Beginner
Preferred location and conditions: Full sun on moisture-retentive soil
Good for containers: Yes
Harvest time: Year round
Possible problems: Slugs and snails, aphids, grey mould, bolting (running to seed)
Health benefits: Lettuce contains vitamins A and C, iodine, potassium, thiamine, riboflavin, calcium, iron and folic acid. It also contains beta-carotene
The ancient Egyptians first cultivated lettuce to produce oil from the seeds, eventually selectively breeding to develop edible leaf varieties. Both ancient Romans and Greeks favoured the crops too. Salads formed a large part of Roman diets, while the Greek island of Kos became the main production area for lettuces during the Byzantine period (hence the Cos types we grow and eat today).
The Greeks believed lettuce induced sleep, and it was known to the Anglo-Saxons as sleepwort. Christopher Columbus took lettuces to America in the late 15th century. These would have been loose leaf types as heading types were not bred until the 16th century.
Why grow lettuce?
Like so many vegetables, lettuce is available year round, but shop bought produce will never equal the flavour and texture of home grown leaves picked and eaten within an hour or two. The range on offer is huge nowadays, from the unjustly maligned ‘icebergs’ (where garden crops are worlds apart from shop-bought) through cos, romaines, butterheads and loose leaf types. They are easy to sow and grow, can be grown in the ground, in patio containers and on windowsills through winter.
Sowing and growing
Lettuce grows best in an open sunny position in light, fertile, moisture-retentive soil. They do not prosper on poor soil, which dries out in summer, leading to the risk of bolting (running to seed rather than forming heads). Sow outdoors from March to September (early and late sowings may need cloche protection). Sow thinly in rows where they are to crop, 1.5cm (½in) deep in soil that has been pre-watered. Seedlings usually appear in 7-14 days and should be thinned to 15cm (6in) apart as they grow. Water regularly to prevent bolting and make sowings every 2-3 weeks to ensure a constant supply of leaves through the growing season. Loose leaf types can be sown and grown on windowsills for winter use. Lettuce grows well in pots of multipurpose compost where space is not available in the garden.