Why Grow Lettuce
It is especially nutritious, particularly the red varieties, and often expensive in stores, especially mixed bags. Lettuce is highly productive, especially when harvested leaf by leaf, and can be grown year-round. Moreover, finding organic lettuce in shops can be quite challenging.
Lettuce serves as the base for their salad mixes, complemented with seasonal extras.
How Many to Plant
The number of lettuce plants to grow depends on consumption habits. However, understanding lettuce growth rates throughout the seasons is crucial. In winter, lettuce requires more space due to slower growth rates—potentially five times as much compared to summer. The quality of winter lettuce is generally lower, so supplementing with Asian greens and Lamb’s lettuce is advisable. For summer, one square metre suffices for five people, while a square metre per person is recommended for winter.
Suitability for Different Growing Environments
Lettuce is adaptable and thrives in various soil conditions. Its shallow roots make it suitable for containers and trays. While it prefers full sun, a bit of shade during summer can enhance its growth. Using covers is beneficial for growing lettuce in late autumn, winter, and early spring.
Lifecycle
As an annual, lettuce naturally goes to seed in late spring and summer. Timing sowing is essential; otherwise, the lettuce bed may bolt in a short period. Sown in late spring, it can be harvested for a few months before seeding, while sowing in August can yield crops until mid-spring. Unlike brassicas, once lettuce bolts, leaf quality diminishes rapidly and becomes bitter, though it can still be used in smoothies.
Sowing and Harvesting Periods
Super Earlies (Sow Early January)
Lettuce can be started indoors under grow lights in January, to be transplanted under cover about a month later. These plants will be ready for harvest by mid-March. This method is useful for early beds or if winter losses occur.
First Earlies (Mid-February for a Harvest in May)
February is an ideal month for sowing lettuce. Late February sowing works best, with no need for grow lights if an unheated greenhouse is available. After hardening off, these lettuces can be planted outside and will be ready for harvest by early May.
Second Earlies (Early May for a Harvest in July)
Sowing a small number of lettuces in May acts as a contingency plan for early crops that may bolt. A few fast-growing varieties can produce lovely hearts over the summer.
Mid-Season Crop (Early June for a Harvest in August)
Lettuce struggles in summer due to lower leaf quality and increased pest challenges. However, early June is the time to sow for summer. Implementing strategies against lettuce root aphid can help mitigate risks.
Early Main Crop (Mid-July for a Harvest in September)
This sowing yields high-quality lettuce in autumn. Sowing in mid-July allows for excellent growth and harvest in September, with low pest pressure.
Main Crop (Early September for a Harvest in November)
The main crop is sown under cover and can last through winter, starting harvests in November. Proper ventilation and multiple plantings can help prevent disease.
Late Crop (Mid-September for a Harvest in December)
Sowing in mid-September stabilises harvest volumes by staggering planting times. These plants thrive under cover, yielding better quality and reduced slug problems.
Super Late Crop (Mid-November for Winter Harvest)
This crop is for dedicated growers aiming for winter and early spring harvests. Growing under cover is essential, with two objectives: winter and spring harvests.
Recommended Varieties
For a selection of recommended lettuce varieties, Wellies and Waxjackets suggests exploring suitable options tailored to specific growing conditions.
How to Sow
There are three methods for sowing lettuce:
- Sow directly in the ground.
- Sow in a pot and prick out into individual modules.
- Sow directly into modules.
Direct sowing is less preferred due to various challenges. Using seed compost, sow seeds about 1cm deep for consistent results.
How to Prick Out/Pot On
Lettuce is easy to prick out, providing reliable results. For direct sowing, placing two seeds in a few modules is advisable. If germination is uneven, transplant accordingly.
Where to Plant
Lettuce grows well in most conditions, particularly benefiting from well-mulched soil rich in organic matter. It thrives in full sun but tolerates some shade into mid-autumn.
How to Plant and Spacing
For interplanting, 25 plants per square metre is optimal, while 30 plants per square metre is suitable for non-interplanted areas, equating to a spacing of about 9-10 inches.
Protecting and Supporting Your Plants
No physical support is necessary, but protection under plastic during colder months can enhance yield and leaf quality. Young plants in summer may benefit from mesh shade covers.
How to Feed and Water
Lettuce typically does not require additional feeding if grown in rich, organic beds. However, calcium sprays in winter can help mitigate tip burn, especially in sandy soils.
How to Prune/Manage While Growing
Removing the first crop of weak, floppy leaves improves overall plant health. Maintaining regular harvesting, whether leaf by leaf or whole heads, keeps plants healthy and reduces bolting.
How and When to Harvest
Twisting leaves off the stem ensures no stalk is left behind, reducing rot. In warmer months, harvest weekly, while winter requires a three-week interval to allow recovery.
How to Store
Harvesting into cold water, washing, and spinning dry is recommended. After brief drying in the shade, store in airtight containers in the fridge for up to seven days.
How to Deal with Pests and Disease
Common pests affecting lettuce include slugs/snails, greenfly, root aphid, and cutworms.
Slugs/Snails
Keeping leaves and soil dry helps deter slugs. Regular harvesting and careful inspection are crucial.
Greenfly
Indicating weak plants, greenfly can typically be washed off without the need for sprays.
Root Aphid
Often unnoticed until damage occurs, prevention through location rotation and resistant varieties is key.
Cut Worms
Cutworms can be managed through bed digging or using nematodes for prevention.
When and How to Remove Plants
To remove, twist off the roots or dig out the root ball if affected by root aphid.
What to Plant Before and After
Understanding crop rotation can enhance lettuce cultivation. Wellies and Waxjackets offers tailored suggestions based on previous and subsequent crops.
What to Interplant With
Salad onions are a preferred interplant with lettuce, requiring careful timing for optimal growth. Other compatible plants include garlic and onions, supporting aesthetic and functional benefits in the garden.
