Planting a crop or closely related crop in the same location year after year can lead to increased incidences of disease and insect infestations. To reduce the pest potential it is recommended to rotate plant families in the garden. This means that a gardener should not plant a crop or related crop in the same garden soil season after season, but instead move the families around within the garden space. For example a tomato planting should not be followed up by a potato planting the following season.
Rotating for one year alone, though better than no rotation, is likely not enough since many diseases that are soil-borne will persist for multiple years. A three year or more rotation would be ideal. Below is a table of plant families.
| Plant Family | Crops |
|---|---|
| Alliaceae | Chive, Garlic, Leek, Onion, Shallot |
| Apiaceae | Carrot, Celeriac, Celery, Parsnip |
| Asteraceae | Endive, Lettuce, Chicory, Sunflower |
| Brassicaceae | Broccoli, Brussels Sprouts, Bok Choy, Cabbage, Cauliflower, Collards, Kale, Kohlrabi, Mustard, Radish, Rutabaga, Turnip |
| Chenopodiaceae | Beet, Spinach, Swiss Chard |
| Cucurbitaceae | Cucumber, Gourds, Muskmelon, Pumpkin, Squash, Watermelon |
| Poaceae | Sweet Corn, Popcorn |
| Fabaceae | Bean, Cowpea, Peas |
| Solanaceae | Eggplant, Pepper, Potato, Tomato |