Crop rotation / Royal Horticultural Society:
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: Pea, broad beans (French and runner beans suffer from fewer soil problems and can be grown wherever convenient)
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
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