Crop Rotations

Put simply, garden crops need to be rotated, or planted in a different spot, each year. 

The reasons usually fall into two categories: First, some plants pull so much of a certain nutrient out of the soil—corn feeding heavily on nitrogen, for example—that the soil needs a year or two with different plants pulling different combinations of nutrients out of the soil to balance things out and recover. Planting different species in succession is almost like letting a field go fallow for a year or two. It’s even more effective than simply letting a field go fallow, however, since gardeners are intentionally rotating through crops that replenish and balance out soil nutrients. Second, the pests and diseases of a plant tend to accumulate in its surrounding soil. Moving them, then, helps break pest and disease cycles. 

One easy way to rotate garden plants is to simply move each block of crops over one spot each year, each one bumping down the garden or bed to the nearest adjacent spot the following year. (If one crop has a particular disease or pest problem, moving plants a couple of spots might be helpful.) Crops that occupy the last spot in the garden or bed get restarted at the opposite end the following year, where they commence their slow march across the garden over the next several years.

This simple crop rotation strategy works great because a diverse set of crops occupy the ground over a long period of time, not letting diseases, pests, or nutrient deficiencies get settled into any one spot. By the time corn, for example, comes back to a spot, crops like beans have replenished the nitrogen and crops like potatoes have given the soil a relative nitrogen rest over the intervening years. And both have helped break the disease and pest cycles of corn, simply by not being susceptible to the same pests and diseases. This way, all garden plants help protect each other over time.

Rotating crops successively down the garden has two other benefits as well: It’s easy, making garden planning a breeze. Plus, it keeps companion planting combinations intact, keeping a gardener from having to redesign them every year. Instead, happy combinations of companions simply shift down the garden or bed together each year.