Gardening: Your Christmas show starts here: If you want to bring colour into the grey of winter, do something about it now, suggests Anna Pavord

THE first ghostly rattle of sleigh bells echoed through the post office this week when the woman in front of me in the queue demanded a list of dates for Christmas posting. She was extremely put out that it had not yet been produced. 'I trust I will be more successful with my next call,' she said as she stamped off down the lane to order her yuletide turkey.

The rest of us in the post office looked at each other guiltily. Not a forward planner among us, it was evident. It is probably something you are born with, this need to cuff and box the year into order, to fill diaries with dates, to order central-heating oil before the tank is even half empty, to fix your next six-monthly check-up at the dentist while your cheek is still throbbing from the results of the first.

I expect the post office dragon has already been to the local garden centre and beaten the manager about the head on the matter of bulbs for Christmas planting. 'Hea-vyyy,' say the children, as they watch these kind of blunderbusses in action. Forward planning is as foreign to them as an eight o'clock breakfast.

But if you want swoony bowls of bulbs to decorate the house in December, you need to do something about it NOW. Think of the smell of lily of the valley or narcissus as you walk into your sitting room out of freezing fog and rain. Think of a brilliant red bowl of tulips on a windowsill that looks out on to a world drained of colour.

You will not get this early flowering with any old bulb. You have to get hold of bulbs that have been specially doctored by the growers and only certain varieties are amenable to treatment.

Growers lift bulbs that are to be forced earlier than usual and store them in a special way giving them extra heat and humidity. Inside any bulb when it is lifted is a whole new plant in miniature waiting to burst out of its package in the next growing season. In a forced bulb, the embryo is encouraged to develop and grow inside the bulb before it is planted. By the time we come along and snatch them up, they are already well revved up.

Treated hyacinths generally come out of store at the end of August. They are probably the most popular of all forced bulbs - pale blue 'Bismarck', white 'L'Innocence', dark blue 'Ostara'. Do not believe anyone who tells you that the primrose yellow 'City of Haarlem' can be forced for Christmas. It is a naturally late variety and will not oblige.

Cool is what all potted bulbs need when they are first planted and, in a centrally-heated flat, this may be difficult to provide. Take the planted bowls to someone else's cool if necessary. The bulbs cannot do without it, for they use this initial cool, dark growing period to develop the roots that will eventually support the shoots. Here cool means 45-50F (7-10C).

The safest (though messiest) way to provide the right conditions for the first half of the forcing process is to plunge the pots under the earth in some shady place in the garden. That way they will be kept at a steady temperature. They will also be dark and damp, which is equally vital.

Or you can put the bowls in a cupboard, though few people have the right sort of damply arctic place. Public health officers do not like them. There are still houses in the country, though, where 50F is considered a positively luxurious inside temperature for November. The reward for the gardeners who live in them is not to have to mess around with burying pots outside. If the bulbs are in a cupboard you must make regular inspections of the compost. Keep it damp. And set mousetraps nearby.

You can use bulb fibre or compost for planting. I generally use compost because the bulbs go out in the garden after they have done a season in the house and I feel the compost provides a few meals for them. It saves them from depleting their own food resources too savagely. But fibre provides better drainage.

Set the bulbs closely together, but not touching, with their noses just bumping out of the top of the compost. Water the bowls well. If you are burying them outside, you can swathe them in sheets of newspaper. This will keep the containers clean but still allow damp to penetrate to the compost.

At the beginning of December bring the bowls in. The flower spikes should be clearly visible crouching between the leaves. The bulbs will now need a period of dark warmth to force the flower spike up. A temperature of 68-70F is ideal and an airing cupboard can provide both heat and dark. Keep the bowls well watered.

When the flower spikes are about 3in tall, bring the bowls out into the light, but keep the ambient temperature at the same high 68-70F. Cover the bowls lightly with newspaper for a few days to encourage the flower spikes to lengthen, then whip them off and wait.

Central heating shortens the life of flowers in bowls. If you can move them outside or on to a balcony for an occasional breath of cooler air, this will extend the show. You will also need to stake the hyacinths as they come into full flower. A continuous fence of string, looped round each stem and round a few thin sticks in between is the easiest way.

Forcing winter bulbs and flowers was once an important task for Edwardian and Victorian gardeners at the large country houses. At Rangemore, near Burton upon Trent, home of Mr Bass of beer fame, 1,600 Roman hyacinths, 600 Dutch hyacinths and 1,200 crocuses were forced every year.

Lily of the valley was also popular. Clumps were dug up from outside beds and brought under cover in peach and vine houses to be forced into flower. At Scone Palace in Scotland, reported the Journal of Horticulture in 1885, one whole acre of the kitchen garden was devoted to lily of the valley, lifted and forced in relays to make buttonholes and nosegays for the house.

Lily of the valley need different handling from hyacinths. Treated crowns are not usually available until late November. Plant them as soon as you get them in peaty compost. Pure sand will do. Keep the pots well watered and in a dark place at a temperature of around 50-55F. If this is inside, stand the pots on trays of damp pebbles so that they are always surrounded by moist air. When the leaves are about 4in high, bring the bowls into full light.

Treated bulbs of hyacinths, lily of the valley, Christmas narcissi and tulips (including red 'Brilliant Star Maximus' and yellow 'Marshal Joffre') are available from Walter Blom & Son, Coombelands Nurseries, Thurleigh Road, Milton Ernest, Bedfordshire MK44 1RQ. Telephone orders: 0234 782424.