Living salads are a wonderfully cheap and easy way of starting a lot of new plants.  The supermarkets’ claim that you can keep cropping from these pots on your windowsill is ridiculous.  There are far too many plants sown too close together in each pot to survive for long as they are all competing for water, light and root space.  Set these sorry little captives free and divide them up into several pots (an activity known as ‘potting on’), or plant lettuces the ground.  They will reward you by producing much larger and healthier plants that you really can crop for weeks.