Every winter I have a lot of fun flipping through plant catalogs, dreaming of harvests that are months away. But I also invest some time in thinking about planning my crop rotation. That time pays off, harvest after harvest, providing important benefits that improve my garden’s yield.
Rotation improves soil fertility. Heavy feeders like lettuce and broccoli take a lot of nitrogen out of the soil. If I grew them in the same place year after year my yields would go down, or I’d have to add a lot of fertilizer. Legumes like peas and beans replenish the nitrogen the soil will need to support nitrogen-greedy feeders another season.
Rotation protects plant health. Many pests and diseases overwinter in the soil. If I plant tomatoes in the same place I had them last year, the caterpillars and fungi that harassed my plants in September will be waiting to attack my new seedlings. If I plant peas in that bed instead, tomato pests can’t feed on them and are more likely to die off harmlessly.
A typical recommendation is a four-part rotation. In the first year you plant a bed with nitrogen-hungry leaf crops--greens and brassicas. The next year, plant fruit crops--tomatoes, peppers, eggplants, squash, cukes, pumpkins. Then it’s time for roots--onions, leeks, carrots, beets etc. Finish the cycle with legumes--peas, beans, clover. Then begin the cycle again. You can start your bed at any point in this rotation.
That’s what the books say. I like to switch things a bit, sowing legumes in the third year and roots in the fourth, because my peas have died by the early fall when the garlic needs to be planted. Your garden conditions may lead you to tweak your rotation too. The key is to avoid planting members of the same vegetable family in the same space. This is especially true for the solanaceids--tomatoes, potatoes, eggplants and peppers--which are vulnerable to pests of all kinds.
Find more ideas about crop rotation, click here or here.