The Importance of Crop Rotation

Keep your garden soil healthy, nutrient-rich, and pest-free by rotating your crops every year.

What Is Crop Rotation?
Crop rotation is the technique of planting crops in a different area of the garden so that no single crop will be planted in the same place two—or more—years in a row.

Why Is Crop Rotation Important?
Crop rotation helps to maintain soil structure and nutrient levels and to prevent soilborne pests from getting a foothold in the garden.

When a single crop is planted in the same place every year, the soil structure slowly deteriorates as the same nutrients are used time and time again. After a few years, the soil becomes unhealthy, drained of those specific nutrients. Simultaneously, insect pests that feed on the single crop—and that spend their larval stage in the soil—become more prolific as their food source remains. These pests become harder to manage every year as their population increases.

What Are the Benefits of Crop Rotation?
Crop rotation is beneficial for four main reasons: (1) Plants that fix nitrogen, such as peas and other legumes, improve soil quality for future vegetables planted in the same bed. (2) Alternating shallow-rooted and deep-rooted plants in a given area draws nutrients from the soil at varying depths. (3) Soilborne pests that feed on one family of plants are hindered because their food source is not in the same location every year. (4) Gardeners and farmers who practice crop rotation do not need to let beds or fields lie fallow (crop-free) as often as they might otherwise.

Plan Crop Rotations
Make a plan on where individual crops will be planted each year. Sow beds organized by plant family: Alliaceae (onion family), Leguminosae (pea and bean family), Brassicaceae (cabbage family), Solanaceae (nightshades family), Umbelliferae (carrot family), Cucurbitaceae (marrow family), and Chenopodiaceae (beetroot family). In a notebook, draw a sketch of your garden beds and label each with a number. Record every spring what you plant in each bed so that no crop is planted in the same bed for two seasons.

If you have a garden this year and have not made a map indicating where specific vegetables grew, do it now in preparation for next year. We all think we’ll remember . . .

Start Small With Three Crops
Beginning gardeners can use a three-bed technique to maintain and rejuvenate the soil. Rotate these groups of crops between three beds over 3 years. Plant the first group in the second group’s bed the following year, the second in the third group’s bed the next, and the third group in the first’s bed the year after.

1. Umbelliferae (carrot family): carrots, celery, cilantro, dill, parsley, parsnips
Condition the soil with compost before planting—plants in the carrot family enjoy soil rich with organic matter. Adding compost sets up the next year’s crop of peas and beans, which do best in rich soil.

2. Brassicaceae (cabbage family): broccoli, kale, radishes, brussels sprouts
Plants from the cabbage family are heavy feeders, leaving the soil in need of amendment. Add compost to the soil at the end of the growing season, which sets up the bed for the following year’s crop from the carrot family.

3. Leguminosae (pea and bean family): all types of peas and beans
Peas and beans fix their own nitrogen from the air and feed extra into the soil. They prepare the bed for the next 2 years’ crops, both of which benefit from an infusion of nitrogen.

Crop rotation does not replace the need to fertilize, mulch, and regularly test your garden’s soil, but it should help you to bring the season to a bountiful close.