Lettuce is a mainstay of our salad bowls. It can be grown in a tub or trough, as well as in the ground. Lettuce (ht 20-30 cm) is often said to do better in the cooler months than in our hot summers, but there are heat-resistant varieties around, so it can be pretty much grown year-round in Sydney, and it will be much more likely to flourish and not bolt to seed too quickly in a part-shaded position in summer, where its soil can be kept as cool as possible - and summer is when we want lettuces for our salads!
There are so many beautifully hued small loose-leaf lettuce varieties around these days, as seeds or seedlings, often available in mixed colours, that it is possible to make a most attractive display of them - even a feature - in a large, low bowl. If you are germinating lettuce seeds yourself, popping the punnet in the frig can be helpful to keep the seed-raising mix cool. If the lettuces are picked by the leaf a few at a time rather than removing the whole plant, the effect is not ruined with a gap and the plants will go on producing for quite some time. Keep lettuce well watered and feed regularly with a soluble fertiliser. Lettuce is a member of the Asteraceae (daisy) family as can be seen in the flower. Generally, I cut the flower stalks off when they start to appear, to eke out a few more weeks of leaf production. However, if the flower stalks are left to develop, the blooms do attract beneficial insects to the garden and you can also allow the seeds to develop for collection.