The reason why we avoid growing closely related vegetables in the same beds, year after year, is because of the way pests and diseases breed.

Most are soil-borne and, being plant-specific, are already waiting in the ground whenever the same crops are grown in the same place. This is why crop rotation is so valuable. Pest and disease breeding cycles are disrupted each time plants are replaced by others that are unrelated.

Where possible, I prefer a six-year rotation system during which time a procession of different vegetables pass through each bed.

We are now well into autumn and the majority of crops started in spring or early summer are being harvested and beds cleared. So the question is — what are the most suitable replacements to go in now for growing through winter and spring?

Luckily, most winter-grown vegetables happen to be lime-lovers so one of the first jobs is to apply lime.

Take tomatoes for example — now starting to look a bit miserable but still cropping. They prefer an acidic soil, but I’m already sprinkling lime generously between and around the plants because it’s now too late to cause tomato problems.

I’m chucking this stuff about because replacement crops will include lime-loving onions, shallots and garlic. In fact I’m already planting hard, solid garlic cloves between some exhausted tomato plants.

Garlic is stimulated into growth by low temperatures. The best crops of fat, hard, well-flavoured and aromatic garlic are always achieved when plants go through a couple of months of soil temperatures below 7C. This is why garlic grown in districts with warm winters rarely develop beyond single round bulbs.

I also plant garlic cloves between rows of January-sown carrots, grown for winter-spring eating, the perfect companion plants.

The beds where acid-loving pot­atoes were grown during summer are given a good, deep cultivation as crops are lifted for winter storage. This soil is almost ready for cool-season crops such as English spinach, Asian brassicas and Japanese turnips, all of which thrive in well-limed soil.

So the ex-potato ground is first given a good liming — I use builders’ lime because it’s so cheap — to sweeten the soil, then watered and rested for three weeks.

That’s long enough to allow me to work in lots of fertiliser without danger of it colliding with the lime.

So in goes lots of well-rotted sheep or cow manure, supplemented with blood and bone fertiliser ready for the next, fairly greedy winter-spring crop.

The Asian vegetables and English spinach are best grown from seeds, sown directly, out in the open garden.

These plants thrive when growing into shortening daylight hours. They resent being transplanted and greatest yields are obtained if roots remain undisturbed.

Those lanky spinach and Asian cabbage seedlings in punnets may look impressive but can be a waste of money. Many tend to bolt uselessly into flower without forming useful leaves or roots.

The soil in beds that grew greedy crops of summer brassicas, sweet corn or pumpkins has usually become fairly impoverished by autumn. This makes the ground perfect for growing soil-enriching broad beans, which thrive through the coldest, frostiest winters.

All the plants need is a good fistful of sulfate of potash, sprinkled over each square metre of ground before sowing seeds.

All other newly cleared beds can also be sown with a mixture of green manure seeds. I buy mine from agricultural suppliers because they are cheaper and offer a far bigger choice than many garden centres.

Green manure crops are mainly composed of winter-hardy plants. They include annual lupins, grey peas and tic-beans, ideal legumes for replenishing lost nitrogen.

For lush green foliage, also scatter and rake in seeds of rye-corn, wheat, barley, feed oats and, to help control nematodes, mustard.

The entire mixture of plants is smashed down and immediately dug in about halfway through July, while still soft and green. The earthworms love this fast-decaying green debris, feed off it and add their superb casts for even greater fertility.

This is the ideal organic way of ensuring that the soil will be actively worked through winter.

Best of all the vegetable patch will be bursting with fertility by the time spring arrives, ready for next summer’s crops.