Lettuce
Where can you grow lettuce?
In Sweden we grow many types of lettuce. The most common types are lettuce, leaf lettuce, iceberg lettuce and head lettuce. The easiest to grow, and the one that gives the steadiest harvest throughout the summer, is leaf lettuce.
Lettuce likes nutrient-rich and moist soil, but will grow in most soils. The location should be sunny or semi-shady. Semi-shade may be preferable, as lettuce must not be allowed to dry out, as this would spoil its flavour. It thrives both outdoors, in a pallet collar and in a (large) pot. A high pallet collar or a larger container of some kind may be preferable as it is then easier to keep hungry slugs away.
Lettuce is excellent for growing in so-called hydroponics. If you have access to plant lighting, lettuce can be grown indoors during the winter.
Sowing lettuce
If you direct sow outdoors, it’s a good idea to sow in batches. Since lettuce doesn’t do well in storage, it’s good to spread the harvest over the summer. Start in April and sow from time to time until June. But bear in mind that lettuce grows less well if it is too hot. If it gets above twenty degrees at night, the seeds won’t germinate.
Sow 1 cm deep and with 30 cm plant and row spacing. You can also sow broadly and then thin out when the lettuce has emerged. This way you will also get an earlier harvest. Water continuously and make sure the plants never dry out. Grass clippings help to retain moisture and also provide nutrients, but increase the risk of slug infestation.
If you are pre-cultivating, you should start a couple of weeks before planting out. The advantages of this are that you get an earlier harvest and that the plants are more resistant to slug infestation. Try to find a bright and cool place to put the plants when you sow. Sow 1cm deep in small pots, a couple of seeds in each pot. Keep the seed moist. Plant out when the risk of frost is over and the plants are about one metre high.
The slug problem
Slugs absolutely love lettuce. Small slug infestations can cause beauty spots on the leaves, but this is something to be reckoned with. If things get bad, however, they can eat entire harvests. However, there are a number of things you can do to reduce the risk of infestation.
The most effective countermeasure is to simply try to remove and kill as many slugs as possible. This is best done late at night, when they are often out feeding. Another important measure is to grow your lettuce in raised pallet collars or containers with some kind of edge – to simply make it harder for slugs to reach the plants. There are a thousand more methods – but we can’t fit them in here.
Harvesting lettuce
Harvesting is done throughout the season. If you haven’t skimped on sowing, you’ll have a steady flow throughout the summer. Pick or cut what you need at the time – but avoid removing whole plants. Lettuce is tastiest and healthiest if you pick it as soon as possible before you are going to eat it.
Don’t wait too long to harvest. Lettuce can become bitter if allowed to grow and is not a great performer after it has flowered. However, you can leave a couple of plants to just flower and then go to seed – then you can harvest the seeds for next year’s seed.
Author: Johanna Damm
Fact-checked by Erik Hoekstra
Last updated 2022-10-14