In fact, the best way to make a clump of snowdrops spread is to lift them immediately after flowering, divide up the mass of bulbs and replant them in smaller groups a few feet apart. Seed dispersal will mean that these clumps gradually meet, and repeated division every few years will further speed the process greatly.

Unless they are growing in grass then you are almost certain to disturb them when and if you plant anything else near to them – which you are almost certain to do as they disappear to nothing by midsummer and do not amount to much after mid-spring, as their foliage gradually withers. (As with all bulbs, resist any temptation to tidy or cut off that foliage because every last scrap of green is essential for the formation of a healthy bulb for next year’s flowers.) In my experience, snowdrops are pretty good at dealing with the trauma of the occasional excavation and as long as they are popped back into the ground quickly they do not seem to suffer. However, a way round this risk is to plant them around the base and roots of deciduous trees and shrubs where they are less likely to be disturbed and will not mind the summer shade. The only thing to watch for is the ground getting too dry – especially in autumn when they start to grow again, albeit underground and out of sight for another few months.

Snowdrops are good as a cutflower if you pick them with a longish stalk. The first tiny bunch of modestly inclined flowers in a vase on the kitchen table is a wonderfully hopeful moment and they have a surprisingly strong honeyed fragrance drawn out by the heat of a room. They also grow well in pots and are ideal for small terracotta pots that you can sometimes find in large quantities at car boot sales. Use a general-purpose potting compost to plant a small clump in each pot and keep them outside in a cool corner, bringing them into the sun in the New Year. You can bring the pots indoors to make a lovely houseplant although the flowers will last longer outside in the cool.

They will not need repotting or feeding every year, but keep them watered from October through to June and every three or four years take them out of the pot, divide them into three, repot into fresh compost and let them get on with it.

No one seems to know if snowdrops are native or not, although because of their longevity and ‘naturalness’ they feel as though they ought to be. There is no reference to snowdrops growing wild before 1770, and indeed, the first garden reference is not until less than 200 years before that, in 1597. And although they seem carelessly natural they have been bred as intensively as almost any garden flower. There are over 350 different species and cultivars, although the differences are really very particular. The common Galanthus nivalis will do me fine although I do love the double G. n. f. pleniflorus ‘Flore Pleno’. This is sterile, so will not spread from seed, but increases perfectly well from divisions and because it does not produce seed it has the bonus that the flowers last an extra long time.

Cavalo nero

Cavalo nero or black Tuscan kale is the most useful brassica growing in my garden and although it is at its best in winter when the leaves have had some frost on them, I grow it all the year round. It can be eaten raw in salads when the plants are young, or left standing from summer through to the following spring for use as cooked leaves. Unlike most cabbage the leaves can be cooked for a long time so are great in stews, soups and sauces. As a pasta sauce with garlic and hot cream it is fabulous.

You pick the leaves individually and the plant replaces them with more and more fresh ones until it starts to flower almost a year after planting.

I sow the first seeds of the year in a seed tray or plugs in January with a couple of extra sowings at monthly intervals. If germinated in seed trays the seedlings must be pricked out into pots before planting out into their final positions in ground that has previously grown a leguminous crop such as peas or beans. The plants grow fairly large so need 60cm (2ft) in each direction and may need staking. If grown as a salad crop they can be sown directly into the soil in rows and thinned to just 10cm (4in). They are a brassica so will need protection from cabbage white butterflies between June and September.

Leeks

Leeks are one of the few vegetables to stand happily through all kinds of winter weather. I have dug them in pouring rain and mud and when the soil has been frozen so hard as to be almost impenetrable. Yes, they freeze solid, so you bring them indoors as a mad, mud-encrusted, Heston Blumenthal-inspired lolly, but once thawed they can be eaten in all their glory.

When I was a child, leek in white sauce was my idea of a treat. That comforting, slightly slimy, bland but distinctive texture and flavour was my perfect comfort food. Still is, although my range of tastes has expanded a little from a Britain in the psychological – if not practical – grip of rationing.

I start sowing my first leeks in February, the wispy green hairs of the new seedlings sharing garden space with last year’s crop for a couple of months. I will make at least three sowings to keep a year-round supply. I used to sow in seed trays and then prick out into 8cm (3in) pots but nowadays I sow direct into the pots, a pinch of seed in each. I also used to plant the seedlings out (in May – as the residues of last year’s crop are making wonderful minaret flowerheads) individually into holes made with a dibber, made in turn, from the handle of an old spade. It was how I was taught to do it as a child. But I now plant in small clumps of 4–8 plants and use a trowel. Less ritual, less rhythm and perhaps less magic, but just as good leeks – and the clumps of small- to medium-sized stems are ideal for each meal. Big leeks, let alone giant ones, are absurd. Keep them small and sweet for the kitchen.

Leek rust (Puccinia allii) has been a problem over the last few years, thanks to the warm, wet climatically changed weather, and I guess will continue to be so. Wider spacing, less compost and even tougher hardening-off regimes will encourage less soft growth which will help, but not stop, the problem.

I am fickle with my loyalty to varieties, although I try to grow at least one heritage variety each year. ‘Musselburgh’ is the oldest British variety, ‘Pandora’ has a blue tinge to the leaves and is fairly rust-resistant, and ‘Varna’ is one of the best for mini leeks, which, my biodynamic, market-gardener friend tells me, is the best-selling vegetable they grow.

Onions and shallots

I sow a batch of onions in the New Year to give them the longest possible growing season, although they will need the protection of a greenhouse or coldframe for another few months, and then a period of hardening off before they can be planted out. I take huge encouragement from this first creative act in the garden of the year, starting new life with the promise of a summer harvest created from this point in the depth of winter.

Planting onion sets

The onion is one of the oldest vegetables cultivated by man and references to onions are found dating from 3200BC in Egypt. One of the reasons why people have always grown them is that they are obligingly easy to get right.

There are two ways of growing them, either from sets or seed. Sets take about 20 weeks to mature from planting. Seed takes perhaps another four weeks on top of that. There are many more varieties of onion available from seed but sets (which are just small onions) are easy to grow and so I always grow some as well as seed. You buy a bag of the small bulbs of a variety that appeals, prepare the soil so that it is fine and soft enough to stick a finger in to the knuckle without any soil sticking to it and then bury the sets so that the tops are sticking out of the ground.

I use a scaffolding board as both a straight edge for the rows and for me to kneel on to avoid compacting the soil. It is a good idea to make sure the sets are in a true grid because then you can hoe in both directions without clipping a bulb in passing. It is important to hoe – and occasionally hand-weed – onions as they respond badly to competition for water and nutrients.

Onions do best in good but lightish soil. If the ground holds too much manure or compost you will have lots of lush leaves but the onions themselves will be on the small side and more prone to fungal problems. Size does not matter so much – in fact a good batch of medium and small onions is more use than ones the size of croquet balls.

I think shallots are as important as onions and they are easier to grow. They tolerate poorer soil, hotter and colder weather and less water than onions. They also have a distinct sweetness of taste and they store much better than onions.

The real difference between onions and shallots is that each individual set or seed will multiply and produce a clump of around half a dozen small bulbs. These are harvested in exactly the same way as onions and when dry I store ours in a wire basket in the potting shed. When we need some for the kitchen I just go and scoop up a handful. If they are kept cool and dark they should reliably store well into spring.

The one essential is that they are as dry as possible before they are stored and the more sun that they have before harvesting the better they will last. As with all bulbs, it is important not to cut off any of the leaves but let them die back completely and dry out before removing the residue for storage. Onions should be lifted carefully with a fork rather than yanked from the soil to avoid damaging the root collar and thus reduce the risk of rot entering the bulb when stored. I always harvest mine on the morning of a hot dry day and leave them to dry on the ground for the rest of the day. I then put them in the greenhouse or on a wooden rack for a few weeks. When they seem to be bone dry I either plait them and hang them up or store them in baskets.

Snow!

As I write this, high up in the hop kiln overlooking the box balls and Ornamental Vegetable Garden, the snow is swirling around the windows and fragmenting the garden below into a thousand soft white shards and spangles.

Snow is lovely but can cause great damage. It can break branches – especially of evergreens – and even topple large trees on a slope as well as crumple seemingly robust structures. Some years ago I put up a fruit cage, bought at great expense, and left the very light netting on after the last of the fruit had been cleared in autumn. An inch of snow that then froze onto the nylon mesh was enough to buckle and bend half the aluminium frame irreparably.

But snow does very little harm to most garden plants and in fact acts as an insulating blanket against icy winds. As it thaws it provides moisture, which makes a muddy mess for a few days but is an important source of water for the spring growth of many plants. In fact, many bulbs rely almost entirely on melting snow for their water supply when growing in their natural habitat. Although it is a myth that it is never too cold to snow, it is true that by and large it only snows in this country at around or just below freezing which is not a disastrously cold temperature for hardy plants. If the snow is more than a few inches thick it will then insulate the ground – and all the plants sheltering beneath its blanket – from any further drop in temperature.

Hardy plants can manage cold, often down to extreme temperatures such as -15°C (5°F), and can sustain cold for weeks or months of about -5°C (23°F). Half-hardy plants such as penstemons, many camellias, or salvias do not, as a rule, tolerate any temperatures below -5°C (23°F) but can withstand the odd touch of frost, and tender plants such as basil or zinnias will not survive below 5°C (41°F).

This temperature, 5°C (41°F), when averaged out across a full 24 hours, is the point at which most plants start to grow. They will grow with increasing vigour and speed as the temperature rises – providing they have sufficient water – until around 25°C (77°F), at which point growth starts to decline at about the same rate that it rose. Of course as the temperature rises and the rate of growth increases along with the size of the plant, the demand for water increases greatly – even though, away from the Tropics, heat is usually associated with lack of water. This is where the effect of snow stretches into summer as plants draw upon the reserves of melt water in the soil.

Winter cold is healthy only because plants prepare for it. Our long autumn and spring wean plants into dormancy and then growth. This is why sudden frost in spring or autumn can have such disastrous effects – especially in spring. A plant that might withstand a month of bitter sub-zero temperatures can have half its growth killed by a few degrees of sudden frost in May. The new growth is not expecting it and although the plant might be conditioned to withstand cold, the new shoots have not had time to put this conditioning into practice. Timing is everything. Late summer growth will not have time to harden before early winter frosts. Grow too early and the same thing happens again – but more so in the spring frosts of April and even May.

Most temperate garden plants have adapted effective means to counter cold. Deciduous trees and shrubs drop their leaves and stop all but minimal root growth. Herbaceous plants will survive frozen ground perfectly happily because they have shut down all growth and gone into a state of hibernation. Annuals die as plants but leave a mass of seed that will survive the cold and grow in spring.

But the greatest damage done by cold to a garden is from the wind. Plants suffer from the wind chill factor just as much as humans, and wind will also dry plants in cold weather as effectively as a hair dryer. If this is combined with frozen soil it will quickly kill the plant. Thus, a still night with a frost of -5°C (23°F) will do little or no harm to any hardy plant. But add a wind of just 15mph to this – scarcely more than a breeze – and the air temperature drops to -12°C (10°F) and quite a few plants will be damaged if not killed. Unless your garden is stocked only by plants adapted to life on the prairie or the steppes, every garden should have hedges and windbreaks that will baffle the wind and break it up, protecting plants growing in their shelter.

Winter pruning fruit trees

This is the perfect time of year for pruning. Short of torrential rain, which is misery beyond the call of duty, you can prune equally well in frost, snow or balmy winter sunshine. In fact, it is a job that I try and do on frosty days when it is impossible to work with the frozen soil.

The purpose of winter pruning is to clear damaged or overcrowded growth, letting more light and air into the plant and to stimulate renewed and more vigorous growth as a result. Every tree and branch will develop a ‘leader’ which grows longer and more vigorously than the rest of the plant. It does this partly by hormones that stimulate more vigorous growth but also by suppressing the growth of the side shoots below them. If you remove that leader the lower shoots cease to be suppressed and will grow more vigorously – until one of them becomes a leader and the cycle is continued. The more you remove the leader, the more the plant will bush out and thicken up.

This means that if you wish to curtail growth, leave the pruning to midsummer when the foliage is fully grown and before the roots start to store food for winter. So, all trained fruit such as espaliers, cordons and fans are pruned now to encourage new growth and replace any weak shoots and then again in July to restrain and reduce excess growth.

All this applies to any deciduous shrub or tree, whether fruiting or not, but do not prune plums, apricots, peaches or cherries in winter. These should be pruned in late spring or early summer and only if absolutely necessary.

Apples and pears follow identical pruning regimes. Most apples and pears produce their fruit on spurs. These spurs take two to three years to produce fruit. So if you prune them off every year you will have lots of whippy stems and no fruit at all! The idea is to establish a framework of branches with plenty of spurs. However, you need light and air to get to them so remove all crowded or crossing branches and if it is a small tree, cut out the leader so it is open like a goblet. It is usually better to cut a few branches right back than to snip away at all of them.

If you are growing standard trees – that is large apples or pears with a clear trunk of at least 2m (6ft) – be brave and remove the lower branches flush with the trunk as the tree grows. This can sometimes involve removing half the growing structure but will speed up the eventual formation of a handsome, balanced, standard fruit tree.

If you are training your fruit trees as cordons, fans or espaliers the majority of your pruning will be in the summer. Only prune in winter to encourage growth. Obviously in the early stages of training fruit there will be quite a lot of winter pruning but as plants get more established this will become less and less. When pruning to train growth there are two things to remember: