Shallow Pots

• Shallow pots such as window boxes are ideal for vegetables that have shallow root systems. Edible Container Gardening suggests using shallow containers to grow radishes, lettuce, herbs and salad greens. Shallow flower pots also suffice, but you can't grow as many vegetables in them, because their overall volume is much smaller than that of a window box.
  
  

Pots for Rooting Vegetables

• Carrots, beets, onions and other rooting vegetables require containers that give them ample room to develop. Read seed packets to find out how long the mature vegetable is, and add 2 to 3 inches to determine the necessary depth for your pot. A 6-inch carrot, for instance, needs a pot depth of 8 to 9 inches so that the carrot and its roots are not stunted.
  
  

Deep-Rooted Vegetable Plants

• Vegetable plants with deep root systems, like tomatoes and peppers, require containers that are very deep. Five-gallon buckets or plastic storage totes or bins offer enough space for the roots to develop deeply. Vegetable with deep roots are also tall and require support, so your container of choice must allow space for a cage or stakes to support the growing plant.
  
  

Reduce, Reuse, Recycle

• The University of Arizona Extension and the Virginia Tech Extension both recommend the reuse of other containers in which to grow vegetable plants. Using containers such as cans, bins, and bottles saves you money and reduces the impact on the environment. Only use containers that never contained any substances that may be harmful to users.