Two groups of vegetables that can be planted in containers are salad plants and root vegetables. SFGate recommends that gardeners should group together plants that benefit each other by preventing disease and insect infestation and encouraging growth.
A group of salad vegetables that can be grown together in a container includes a tomato plant surrounded by lettuce, spinach, strawberries and carrots. The plants' roots will not conflict with one another. Adding sage and rosemary also fights against insects.
Root vegetables such as beets, carrots, onions and turnips can be planted together in a container. Growing lettuce on the surface of the soil helps retain the soil's moisture, and adding summer savory increases the onion crop.