By Emily Swihart
As the growing season approaches, final plans are being made for home gardens. What to plant and where to plant are big questions that require multiple levels of consideration. What to plant requires an analysis of the intended use, what the growing space can support, and how the climate will impact production. Where to plant requires an analysis of the site including soil type, sun exposure, availability of water, ease of access, and more.
One question that is easy to overlook, if considered at all, is what was planted in this space in the previous years? By knowing what has been planted in previous years, you can use this information to develop a crop rotation plan and implement the first phase in the coming season.
What is crop rotation?
Crop rotation is a strategy of garden planning and planting that prioritizes planting crops of different families in the same area of a garden in successive years. Rather than growing the same crops in the same location year after year, a crop rotation involves planting members of the same plant family in different locations in the garden from year to year. Rotating crops in a garden can help manage pests and diseases, improve soil fertility, and increase crop yields.
The most effective crop rotation schedule allows for three to four years between planting crops of the same family in the same location. Keeping a garden log from year to year, including a map, diagram, or photos, helps track garden history and can be used to make informed planting decisions.
Benefits of crop rotation
Pest and Pathogen Management: Many plant pests and pathogens target specific plant families. When crops within the same family are planted in the same location year after year, soil-borne pests and pathogens can accumulate because, in successive years, they are provided with a host plant that supports their success. Moving plant families to new garden locations can help interrupt the lifecycle of pests and pathogens and reduce their prevalence.
Improved Soil Health: Garden plants within the same plant family tend to utilize similar types and amounts of nutrition. When the same crops or vegetables within the same family are planted in successive years on a site, the soil may become depleted of critical nutrients. Rotating crop families helps moderate the use of nutrients and provides an opportunity for high demand nutrients to be replenished.
Vegetable crops have varying root structures, which can improve soil aeration and drainage. Crops with penetrating or extensive root systems such as corn, carrots, turnips, and tomatoes can help break up compacted soils and bring nutrients to the surface. Fast growing or shallow rooted crops such as leafy greens can help protect the soil from erosion.
Strategies for rotation
In the home garden, it is easiest to implement a crop rotation plan when separate garden beds are utilized. Installing three to four raised beds or distinctly separate garden beds makes a rotation plan straightforward: identify the garden crops to be grown, identify and group crops according to the plant families, and plant related crops in a bed together. In the following years, plant the same or similar crops in a group while rotating the garden bed.
If space is limited, it may be necessary to work with neighbors, family, or friends to implement an adequate rotation. The benefits of crop rotation can be achieved, and harvests can be shared.
Plant families of common garden vegetables
- Amaranthaceae (amaranth family): beet, spinach, Swiss chard
- Amaryllidaceae (amaryllis family): chives, garlic, leek, onion, scallion
- Apiaceae (carrot family): carrot, celery, parsley, parsnip
- Asteraceae (sunflower family): endive, lettuce, sunflower, salsify
- Brassicaceae (mustard family): broccoli, Brussels sprouts, cabbage, cauliflower, Bok choy, collards, kale, kohlrabi, radish, rutabaga, turnip
- Cucurbitaceae (gourd family): cucumber, muskmelon, pumpkin, summer squash, watermelon, winter squash
- Fabaceae (pea family): bush bean, green bean, kidney bean, pole bean, wax bean, pea
- Poaceae (grass family): ornamental corn, popcorn, sweet corn
- Solanaceae (nightshade family): eggplant, pepper, potato, tomato, tomatillo
Crop rotation is a simple yet powerful method to maintain a productive and sustainable vegetable garden. By planning a strategic rotation of crops, healthier soil, fewer pests and diseases, and a more robust harvest can be achieved.
Good Growing Fact of the Week: Cucurbitaceae utilize large amounts of nitrogen, but Fabaceae help replenish nitrogen within soils.
Source : illinois.edu