How to Grow Lettuce
Homegrown lettuce is nothing like the limp leaves you’ll find in the supermarket. With the huge variety of shapes, colours and textures available, it’s easy to grow your own delicious, colourful salad.
When and how to sow your seeds
Lettuce can be sown almost all year round, from February to October. Different varieties are suited to different seasons, so check the information on your seed packets to ensure you are sowing them at the correct time of year. For a summer crop, sow from February indoors or March outdoors, protecting from frost. For an autumn/winter crop, sow in early August.
For a late winter/early spring crop, sow in September or October. For a continuous harvest all season sow every couple of weeks.
We find lettuce germinates well scattered in a seed tray with a light covering of vermiculite or compost. Prick out and transplant seedlings into larger modules when at the true leaf stage. Keep seedlings moist and in a sunny spot.
Plant out into final position at 20x30cm spacing.
Add a light dressing of compost to the lettuce bed before planting. Keep the bed moist and well weeded, removing rotten leaves from the lettuces to reduce disease and pest predation. Water more regularly in hot weather to prevent the lettuce from trying to go to seed.
Pests and Diseases
Slugs and snails can be a major problem when growing lettuce. Remove dead or rotten leaves to reduce places for them to hide. Experiment with different varieties to see which are least damaged in your growing space.
Downy mildew fungus can be a problem, particularly in wet, humid weather near the end of summer. Avoid splashing the leaves when watering and make sure lettuces aren’t planted too densely so there is plenty of airflow between each plant.
You will be able to start picking 6-10 weeks after planting depending on the variety. Harvest your lettuce during the cool hours of the day to prevent wilting and keep leaves crisp.
There are a number of ways that lettuce can be harvested. Some varieties form tight heads and are harvested as an entire head, some have looser leaves that can be harvested one by one, others can be cut near the base with a knife and left to regrow. Check the packet to see what is recommended for your variety.
Select the plants you want to save seed from (based on health, disease resistance, true to type characteristics etc) and transplant at 45x45cm, ideally under cover. Remove the bottom leaves when they begin to flower and use bamboo canes or build a structure to keep plants supported.
Lettuce seeds are ready to harvest when the fluffy ‘papuses’ are open on the seed heads. There are three main ways to harvest the seeds, depending on how many plants you have. Either harvesting individual seed heads if you only need a small number, shaking the seed heads into a bucket multiple times or as a whole plant harvest when 80% of the seed heads are showing papuses.