Crop Rotation for the Vegetable Garden
Crop rotation is a vital aspect of planning your vegetable garden. Planting the same crop in the same location year after year can lead to soil deficiencies and a build-up of pests in the soil. By rotating your crops, different nutrients are removed from the soil each year allowing the soil to balance itself out over time, and the pests cannot re-establish themselves when their host plant is absent from the soil.
Crop rotation is generally divided in to four sections. Each section containing similar families of crops. Draw up a planting schedule at the beginning of the season so that you know what seeds to order and how many of each crop you can fit in to each area.
There are certain plants that don’t work with crop rotation, such as rhubarb and asparagus (perennial crops that can remain in one location). While others can be grown wherever convenient, such as, courgette, squashes, French and runner beans, sweetcorn and lettuce.
It is common for crop rotation to cover four years as it takes this long for harmful levels of most soil-borne pests and diseases to deteriorate. Each group does not occupy the same ground more than once every four years.
Decide which crops you would like to grow and divide them into groups – legumes, onions, roots, potato and brassicas. You can also set aside an area for your perennial crops which won’t move with each rotation. Divide your planting area into equal sizes – one to accommodate each group you are planting (onions and roots often occupying the same section). If you have an area that will have fewer crops in than others, use this area for planting ‘convenient’ crops such as lettuce, squash and courgette that are not as prone to soil-borne diseases (but don’t grow too often in the same place).
Legumes – pea, broad beans, mange tout, borlotti
Onions – onion, garlic, shallot, leek, chive
Roots – beetroot, carrot, celeriac, celery, parsley, parsnip, coriander, dill, spinach
Potato – potato (tomatoes are the same family as potatoes but it is not advised to grow them together as it may cause an increase in blight)
Brassicas - Brussels sprouts, cabbage, cauliflower, kale, kohl-rabi, oriental greens, radish, swede, turnips, broccoli, pak choi, rocket
Convenient - courgette, cucumber, squashes, French and runner beans, sweetcorn, lettuce, endive, chicory, pepper, aubergine, okra, mint, oregano, rosemary, sage, basil
Perennial – rhubarb, asparagus, globe artichoke, soft fruits such as raspberries
Royal Horticultural Society - https://www.rhs.org.uk/advice/profile?PID=124
Growveg.com - http://www.growveg.com/growguides/crop-rotation.aspx