It just doesn’t work to plant the same crops in the same place year after year. Different crops have different nutrient requirements, so growing the same crop in the same place time after time will drain the soil of the particular nutrients taken up by those plants, leading to reduced yields each year. Rotating crops keeps your soil healthy, at the same time disrupting the life cycle of pests and diseases and reducing the spread of soil-borne disease.
Rotation also allows you to prepare the ground specifically for the crop you are growing so, for example, potatoes and brassicas need a lot of manure, brassicas benefit if you add lime to the soil, and so on. Legumes produce nitrogen, which leafy green veg love but root vegetables really don’t like (they end up putting all their energy into top and not where you want it – in the roots).
There are all sorts of plans for rotating your garden but I have always loosely followed John Seymour’s easy rotation, which is based on four beds and a four-year cycle. He says, “Manure that land heavily and sow potatoes. After the potatoes are lifted, lime the land heavily and the next year sow peas and beans. Once the peas and beans are lifted, set out the brassicas immediately from their seedbed. The brassicas will have been eaten by the next spring and it will be time for the mixed crops, and follow these with the roots, then back to spuds where we started."
Under miscellaneous I fit all the solanaceae family – tomatoes, peppers, eggplants, as well as salad greens. I plant corn and zucchinis and other cucurbits in with the legumes, following the principles of the Three Sisters garden.
Potatoes love nitrogen-rich soil, but should not be planted alongside brassicas as they like different pH levels, which is why they sit in a different part of the rotation. I don’t tend to plant tomatoes and potatoes in the same bed as you can get a transfer of blight. Put pumpkins somewhere they can run, and make sure you give them lots of compost and manure.
The following chart shows the planting cycle for a garden with four beds over a four-year cycle. To download a printable pdf (1.9MB) click here.