Recently a search turned up in the stats, someone was asking if cos lettuce can be grown in a 6 inch pot. The answer is yes!
My experience has been that even in deep, rich composted soil lettuce, rocket, coriander and spinach have quite neat little root systems that could be held in a large hand. By 6 inch pot, I’m assuming this means 6 inches across the top and about 7 or so inches deep. That would certainly be enough for a cos lettuce or any other variety for that matter.
Position your lettuce or salad green in its pot where it gets plenty of sun. In summer, giving it morning sun and then dappled shade in a position where the pot itself is not in the sun, will keep the soil from drying out too much and stop the plant from going to seed too quickly. In winter, give it the full 8 hours of sun and sunlight also on the pot to warm the soil and encourage the roots. Lettuce and spinach are a cool climate plant so it might pay to check your heat and cold zones or ask an experienced local gardener for more advice. I’m certainly happy to answer any questions if you wish to leave a comment here.
Lettuce like rich soil, so choose a good quality potting mix with a bit of blood and bone or some well composted garden soil. Keeping the water up to them will prevent them becoming bitter. Once they go to seed, however, the leaves will be a bit sharper to taste. You can pinch out the stem when it starts to grow up tall as it starts seeding, but it will only produce four more seed stems and the taste will still be stronger.
Normally I stagger planting of lettuce and allow them to self sow, so that there’s always a few plants around to take a few leaves from and still leave them to re-seed. If you have limited space it might be an idea to stagger the planting and harvest them as you need, but leave one or two in the pots to seed so you can save your own organic seeds.
Lettuce are pretty easy to grow and are good for the skin, nails and hair. If you’d like to have a try at growing some organic greens, they’re a good place to start.