Creating a vegetable patch, whether on a large piece of ground or within a smaller raised bed, can bring rich rewards if you plan carefully.
Growing compatible crops together is likely to reap richer harvests, while not treading soil from one bed to another and keeping your tools clean between use will help keep soil healthy and reduce the likelihood of the spread of pests and diseases.
The idea behind crop rotation is that you avoid planting the same crop in the same bit of ground more than one year in four to stop root diseases building up and to make the most of resources such as manure, which is only needed for certain crops but not for others (like root crops).
Crops which can be grown together include legumes (peas and beans), comprising peas and broad, French and runner beans; the onion family, including garlic, leeks, onions, shallots and spring onions; roots and tubers, including carrots, parsnips, beetroot, potatoes and tomatoes; and brassicas (cabbage family), featuring Brussels sprouts, cabbages, Chinese greens, pak choi, radish, cauliflowers, swedes and turnips.
Green veg which require regular watering can be separated from less thirsty root crops, lettuces are often grown with cabbage family crops as they need organic matter, nitrogen fertiliser and regular watering. Perennial veg like rhubarb and asparagus are best kept out of crop rotation beds.
Squeeze quick-growing crops of lettuce and other salad leaves wherever they will fit, using them as a catch crop between slower-growing types such as winter brassicas.
By swapping the main groups of vegetables around in a regular order, you can make best use of the nutrients in the soil because different crops need different amounts of nutrients.
If you’re starting a new plot or creating raised vegetable beds, prepare the ground thoroughly, digging to break up compacted soil and weeding thoroughly. Then add bulky organic matter before planting season starts. It may be better to do this in spring, using compost as a surface mulch.
If you have an existing vegetable plot, dig it over each winter, inverting lumps of soil to bury annual weeds, but leave the clods intact. Frost and rain will break them down and leave a crumbly soil by spring. On light, sandy soils, wait until spring before digging. Sandy soils may also need liming regularly to give them a neutral pH. If in doubt, buy a soil tester to test the pH of your soil.
The four-year rotation is a good technique which is easy to plan. Divide your plot into four separate sections if you have space, and then operate a four-year rotation on each.
A typical example might be:
Plot A - potatoes; Plot B - pea family; Plot C - Cabbage family; Plot D - onions and roots.
Plot A - pea family; Plot B - cabbage family; Plot C - onions and roots; Plot D - potatoes
Plot A - cabbage family; Plot B - onions and roots; Plot C - potatoes; Plot D - pea family
Plot A - onions and roots; Plot B - potatoes; Plot C - pea family; Plot D - cabbage family
On smaller plots, conventional crop rotation is not practical, so just aim not to grow the same crop on the same patch of ground any more often than you need to. Separate the main crop groups as far as possible. Grow potatoes, onions and the cabbage family on a different area each year and fit other crops around them.
Keep a yearly plan as to what you have grown where - and you won’t go far wrong.