Remember the lyrics to the Byrds’ song: “There is a season, Turn, Turn Turn”? I don’t think they were talking about vegetable gardening, but the line is very appropriate. Rotating your garden vegetable crops is essential to reducing pest damage and maintaining good nutrition for your plants.
The benefits of rotation include reduced need for control of garden pests, maintenance of the soil structure, and a reduction of the spread of soil-borne diseases. Some of the simple plans for rotation divide garden plants into four groups: legumes, root vegetables, leafy greens and fruit. While they are easy to understand, they do not go far enough for maintaining a healthy garden.
Dividing your garden into plant families gives you more rotation possibilities and gives attention to pests and nutrition specific to those families. The families include: 1. Brassicas (the cabbage family), 2. Legumes (beans and peas), 3. Solanaceae (potatoes, peppers and tomatoes), 4. Alliums (onions, leeks, garlic), 5. Umbeliferae (carrots, parsnips, dill, etc.), 6. Cucurbits (squash, cukes, melons), 7. Beet Family (beets, chard, spinach), and 8. Miscellaneous (fruit, herbs, lettuce, corn).
In good rotation practice onions and garlic should not be planted in the same spot for three years. Pests that attack these bulbs complete their life cycle very close to the plant and moving your onions and garlic to a different spot interrupts that cycle. The same can be said for any of the brassicas. You probably have experienced this if you have grown turnips.
Potatoes, tomatoes, and peppers have many fungal enemies. They benefit from being planted in an area that has had a cover crop for a year, if possible. They should be followed by legumes to enrich the soil.
While corn and potatoes are very heavy feeders, legumes enrich the soil. Planting corn or potatoes in the same spot year after year not only encourages disease but also depletes the soil nutrients rapidly. If you garden organically, compost and manure need time to work in the soil to provide adequate nutrition.
To practice crop rotation, divide your garden into four or more distinct areas and plan to grow crops from one of the families in each area. Each year crops from a different family should go into a new space. Taking it a step further, plan to let the brassicas follow legumes so they benefit from the nitrogen the legumes have fixed in the soil. Vegetables from different groups can share a space if they have similar requirements. Some plants are exempt from rotation for obvious reasons. You really don’t want to rotate rhubarb, asparagus, or your grape vines!
The best way to get started is to plan out your garden now before the first seeds or plants go in. Make a chart and divide into at least four areas for planting and keep a record from year to year. Following a rotation schedule should result in a healthier, more productive garden.
For more information on gardens in Minnesota check on-line for locations, addresses and directions. Look for information about horticulture on the University of Minnesota Extension Home and Garden Information page www.extension.umn.edu/gardeninfo or on the Beltrami Master Gardener site beltramicountymastergardeners.org.
