The lettuce is a very fast growing annual with succulent and crisp leaves which is the basis of just about any salad. It comes in a wide range of shapes, textures, tastes and colours. They include Iceberg, Cos, Butterhead or Looseleaf. Lettuce will go to seed easily so its important to grow just enough to consume at any one time. They make an excellent contrast in a border in amongst the summer annuals.
N.B. you can grow these in pots even if you do not have a veggie patch - they'll grow anywhere, even a balcony of an apartment.