We grow most of our salad in SaladScapes and window boxes. Lettuces can be grown in trays as shallow as 4" (10cm). A 'SaladScape' is a lettuce tray grown for beauty, not just salads.

These trays are fertilized with worm castings generated from kitchen scraps and shredded bank statements. As they're growing, you can harvest a few large leaves from each plant for sandwiches or a lunch salad. Once the lettuces are fully grown--in 6-8 weeks--you can cut them off 1 1/2" from the ground with a pair of scissors, for the primary harvest. Water the tray, and a couple weeks later you'll get a second, smaller cutting.