Crop rotation is used in allotment plots and kitchen gardens for most annual vegetable crops. Perennial vegetables (such as rhubarb and asparagus) do not fit into the rotation. Certain annual crops such as cucurbits (courgettes, pumpkins, squashes, marrows and cucumbers), salads (endive, lettuce and chicory) and sweetcorn can be grown wherever convenient, merely avoiding growing them too often in the same place.

Plan your crop rotation before the

The period of time when an individual plant is in active growth. This will depend on the local climate and light levels, and can vary between different plants, although it is broadly from spring to autumn.

Soil fertility: Different crops have different nutrient requirements. Changing crops annually reduces the chance of particular soil deficiencies developing as the balance of nutrients removed from the soil tends to even out over time.

Weed control: Some crops, like potatoes and squashes, with dense foliage or large leaves, suppress weeds, thus reducing maintenance and weed problems in following crops.

Pest and disease control: Soil pests and diseases tend to attack specific plant families over and over again. By rotating crops between sites the pests tend to decline in the period when their host plants are absent which helps reduce build-up of damaging populations of spores, eggs and pests. Common diseases that can be helped avoided by rotation include clubroot in brassicas and onion white rot.

Divide your vegetable garden or allotment into sections of equal size (depending on how much of each crop you want to grow), plus an extra section for perennial crops, such as rhubarb and asparagus. Group your crops as below:

• Brassicas: Brussels sprouts, cabbage, cauliflower, kale, kohl-rabi, oriental greens, radish, swede and turnips
• Legumes: Peas, broad beans, French and runner beans 
• Onions: Onion, garlic, shallot, leek
• Potato family: Potato, tomato, (pepper and aubergine suffer from fewer problems and can be grown anywhere in the rotation)
• Roots: Beetroot, carrot, celeriac, celery, Florence fennel, parsley, parsnip and all other root crops, except swedes and turnips, which are brassicas

Move each section of the plot a step forward every year so that, for example, brassicas follow legumes, onions and roots, legumes, onions and roots follow potatoes and potatoes follow brassicas. Here is a traditional three year rotation plan where potatoes and brassicas are important crops:

Year one
Section one: Potatoes
Section two: Legumes, onions and roots
Section three: Brassicas

Year two
Section one: Legumes, onions and roots
Section two: Brassicas
Section three: Potatoes

Year three
Section one: Brassicas
Section two: Potatoes
Section three: Legumes, onions and roots

This is a four-year rotation for where potatoes and brassicas are not as important, but more legumes (which take up a lot of space) and onion-type crops are required:

Year one
Section one: Legumes
Section two: Brassicas
Section three: Potatoes
Section four: Onions and roots

Year two
Section one: Brassicas
Section two: Potatoes
Section three: Onions and roots
Section four: Legumes

Year three
Section one: Potatoes
Section two: Onions and roots
Section three: Legumes
Section four: Brassicas

Year four
Section one: Onions and roots
Section two: Legumes
Section three: Brassicas
Section four: Potatoes

Links

The Lindley Library - find more veg books in the online catalogue