A home gardener’s guide to crop rotation

A couple of weeks ago I wrote about getting an early start on your vegetable garden and I mentioned crop rotation — the practice of rotating where in your garden different varieties of fruits and vegetables are planted.

Crop rotation is important for a successful home garden and should be taken into consideration when planning out what you’ll plant and where you’ll plant it year after year. Rotating crops helps replenish the soil, which in turn improves yields. Additionally, it prevents pests and diseases that were an issue last year from being a nuisance again.

Understanding the role of garden plant families

The first step to successfully rotate crops in the home garden is to understand different plant families and how they affect the soil. Ultimately, your garden crop rotation should go from heavy feeder to light feeder to soil enricher from one year to the next.

• Aamaryllis family: Onions, leeks, chives, garlic, shallots (Light feeders)
• Carrot family: Carrot, parsnip, celery, fennel, parsnips, parsley, celeriac, cilantro, dill (Mostly light feeders)
• Sunflower family: Endive, artichoke, lettuce, celtuce, sunchokes, sunflower, salsify, dandelion, chicory, radicchio (Heavy feeders)
• Mustard family: Arugula, broccoli, brussels sprouts, cabbage, cauliflower, collard, horseradish, kale, kohlrabi, mustard greens, radish, rutabaga, turnip, watercress (Heavy feeders)
• Goosefoot family: Beet, chard, spinach, amaranth, quinoa (Light to medium feeders)
• Gourd family: Cucumber, melon, pumpkin, squash, watermelon, summer squash, zucchini, gourd (Heavy feeders)
• Pea family: Bean, Peanut, Pea, lentil, soybean, alfalfa, cowpea (Soil enrichers)
• Grass family: Corn, millet, rice, barley, wheat, rye, oats, sorghum (Heavy feeders)
• Knotweed family: Buckwheat, rhubarb (Heavy feeders)
• Nightshade family: Eggplant, pepper, potato, tomato, tomatillo, tobacco (Heavy feeders)

You can begin planning this year’s garden once you understand which plant families are heavy feeders, light feeders and soil enrichers. The sunflower family, mustard family, gourd family, grass family, knotweed family and nightshade family are the heavy feeders and shouldn’t be planted in areas of your garden where heavy feeders grew more than two years in a row. Ideally, they would be planted where members of the pea family — the soil enrichers grew — the year before and members of the aamaryllis, carrot and goosefoot families — the light feeders — would be planted where the heavy feeders grew. Finally, members of the pea family would be planted where the light feeders grew the year before to replenish the soil.

Preventing pests and diseases with crop rotation

Keeping a heavy feeder to light feeder to soil enricher rotation ensures healthy soil year after year; however, you also need to avoid planting members of the same plant family in the same location year after year to avoid pests and diseases.

Planting vegetables from each plant family in different areas of your garden each year limits pests and diseases because plants from the same family are often susceptible to the same pests and diseases. Planting plants from the same family in the same places year after year allows soil-borne diseases to build up and makes it easier for overwintering insects to find food when they wake up.

You might also consider companion planting — a strategy where certain plants are placed near each other to provide pest control and other benefits — to limit pests. One example of companion planting would be growing garlic between rows of tomato plants to prevent pests from an infested row from jumping to the next. You can find tips on companion planting by reading our beginner’s guide.