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:

Year One

Plot A - potatoes; Plot B - pea family; Plot C - Cabbage family; Plot D - onions and roots.

Year Two

Plot A - pea family; Plot B - cabbage family; Plot C - onions and roots; Plot D - potatoes

Year Three

Plot A - cabbage family; Plot B - onions and roots; Plot C - potatoes; Plot D - pea family

Year Four

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.

BEST OF THE BUNCH - Christmas cactus (Schlumbergera)

These low-maintenance houseplants come into their own in the festive season when their vibrant pink, red and purple flowers burst into bloom on long, arching, succulent stems. Buy them in bud and place them on a windowsill, or somewhere light but not with direct sunlight. They like humidity so place them on a moist, gravel-filled saucer, and keep them at a minimum temperature of 55F and water regularly. If you want them to come back when they have finished flowering, they need a resting period from January to March when you should put them in a cooler room and reduce watering. Their growing season is April to September, when you need to increase watering and move them to a warmer spot, maintaining a temperature of 18-20C (65-69F) if possible. You can put them outside in a shady spot in summer, but they will need a second resting period from mid-September, keeping them dryish and cool until the flower buds form.

GOOD ENOUGH TO EAT - Rhubarb

After paying an extortionate price for rhubarb at my greengrocers (£3.80 for three stems) I think it's about time we all started growing our own, given that rhubarb is one of the easiest vegetables to grow. This long-lived perennial needs little attention and can also look spectacular in a herbaceous border, with its huge leaves and bright-red leaf stalks. Grow it in a sunny spot in moist but not waterlogged soil. Plant dormant crowns in late autumn or early spring in richly manured soil, allowing 90cm (3ft) between plants. Remove any flowering stems which develop in summer - these are the strong, upright ones growing through the centre of the plant - cutting them out as close to the base as you can. When the foliage dies down in autumn, remove the dead leaves, sprinkle fertiliser around the plants and mulch generously. For early stems, force rhubarb by covering a well-established crown with an upturned dustbin in mid January or early February. When you see long stems with pale yellow leaves appearing, pull as many as you want until the end of March, uncovering the plant to allow it to grow naturally and taking just a small crop of stems for the rest of the season.

WHAT TO DO THIS WEEK

:: Order or buy seeds of plants that need to be sown in mid and late winter to ensure they get the long growing season they need

:: Plant brightly coloured winter stems such as dogwood, willow and rubus, to give your garden a boost

:: Prune winter-flowering shrubs over three years old after flowering

:: Keep Christmas hyacinths cool or the leaves will grow quickly and obscure the scented flowers

:: Remove mummified fruit from apple trees but don't add them to your compost bin or they could spread disease

:: Continue to plant bare-root hedging

:: Harvest winter brassicas including Brussels sprouts and sprouting broccoli

:: Continue winter digging if the soil isn't too hard, but stay off clay soil until the weather is dry

:: If your acer needs pruning, do it now while it is dormant to stop the wounds bleeding sap and weakening the plant

:: Take hardwood cuttings of willow, buddleia and dogwood to increase your stock