Crop rotation is the practice of changing or alternating the crops in a given area of the garden. Rotating crops will stem the depletion of soil nutrients and prevent or reduce the build-up of pest and disease problems.
Crops that are heavy feeders and require more soil nutrients can be rotated with light feeders and soil-enriching crops, such as legumes.
Pest and disease problems can be minimized by not planting members of the same plant family in same part of the garden more than once every three or four years.
Here are the major vegetable plant families and suggestions for crop rotation:
Onion Family, Amaryllidaceae: Garlic, onions, leeks, shallots. These are light feeders. Plant onion family crops after heavy feeders. Follow onion family crops with legumes.
Cabbage Family, Brassicaceae (Cruciferae): Broccoli, Brussels sprouts, cabbage, cauliflower, Chinese cabbage, collards, cress, kale, kohlrabi, radishes, turnips. These are heavy feeders. Plant cabbage family crops after legumes. After cabbage family crops build the soil for a season with a cover crop or soil building compost or let the area sit fallow for a season after applying well-aged manure.
Lettuce Family, Asteraceae (Compositae): Artichokes, chicory, endive, lettuce. These are heavy feeders. Follow lettuce family crops with soil building legumes.
Grains, Grass Family, Poaceae (Gramineae): Grains--oats, corn, rye, wheat. Follow these crops with tomato family plants.
Legume Family, Fabaceae (Leguminosae): Beans, peas, clover, vetch. These are soil enrichers. Follow legume family plants with any other crop.
Tomato Family, Nightshade Family, Solanaceae: Eggplant, peppers, tomatoes, potatoes. Nightshade family crops are heavy feeders. Plant these crops after grass family plants. Follow heavy feeders with legume family crops to re-build the soil.
Squash Family, Cucurbitaceae: Cucumbers, melons, summer and winter squash, pumpkins, watermelon. Squash family plants are heavy feeders. Plant these crops after grass family plants. Follow heavy feeders with legume family crops to re-build the soil.
Carrot Family, Apiaceae (Umbelliferae): Carrots, celery, anise, coriander, dill, fennel, parsley. These are light to medium feeders. Carrot family crops can follow any other crop. Follow carrot family crops with legumes or onion family crops.