OF ALL the garden facilities, the cold frame is the one that is most under-rated. If you have a greenhouse it is the place to wean young plants prior to planting in the garden. If you do not, then it is a useful protection for over-wintering plants and a safe haven for summer sowings of hardy perennials.

Buy or make a cold frame now and its benefits can be enjoyed immediately. However, take great care in your choice, for some structures are more versatile than others. For the smaller garden the portable bottomless frame is the most useful and versatile. This can either be placed on a hard surface in a suitable corner and filled with trays or pots of plants and seedlings, or stood out in the open garden over well cultivated soil.

Vegetable gardeners always find a moveable cold frame indispensable. It can be placed over an area of prepared soil, closed down in order to exclude rain and warm up the soil, and then seeds can be sown or young plants established.

Protection can be provided for as long as necessary and then the entire structure lifted and removed to another part of the garden, allowing the plants that were nurtured with its protection to continue growing undisturbed.

This can also be done with some of the hardier bedding plants. Indeed a number like pansies, polyanthus, cushion daisies and pinks enjoy the cool conditions of a frame during their early life, but benefit from its protection.

While the majority of bedding plants are sown into pans or seed trays, there is no reason why they cannot be sown or pricked out into good quality soil in the open ground if given the protection of a frame.

Some frames are more permanent structures, often made from brick or concrete. These are less versatile, but are excellent for the seed raising of perennial and alpine plants and the wearing of tender bedding. Often attached to a greenhouse, they are much warmer than the portable metal or wooden frame. The frame cover is usually more substantial too and usually glazed with horticultural glass or polycarbonate.

As these are permanent structures it is important that they face in the right direction and have plenty of space around them, especially for when the tops have to be removed in a confined space, frame management can be extremely tiresome.

In addition to the convenience of management, the frame should receive the maximum of sunlight. The only exception to this is if you are rooting cuttings directly into it, then some kind of shading must be provided.

It is better to create the shading artificially than to place the frame in a shady spot. Ideally it should face south, although a westerly aspect is equally tolerable.

It should not be too far from a water supply and close to a hard path or patio. A well run frame can make an enormous difference to both the efficiency and pleasure of gardening, and now is as good a time as any to acquire one.

WHAT'S NEW

Green Utah is a green stemmed celery.

Moonwalker is a multiflowered sunflower.

Seven Hills is a late maturing, mildew-resistant Brussels sprout.

Q All the leaves on my poinsettia have dropped off. I am just left with the red bracts. What has gone wrong?

A Your poinsettia has almost certainly been chilled. If it is a new plant it may have been chilled on the way home. Established plants can suffer from draughts or being shut behind the curtains. If provided with a consistent warm temperature in a draught-free position they usually recover.

Q My lawn is covered in worm casts. How can I get rid of them?

A Until recently it used to be possible to get a chemical to water on the lawn which would kill the troublesome worms. This has now been withdrawn from sale. Keep the lawn as free from fallen leaves as possible, as worms enjoy coming up for these and pulling them into their burrows. Brush off worm casts with besom.

Q My roses are very untidy. Can I prune them now?

A It is important to take the weight out of the past season's growth to prevent the bushes from blowing about, but they should not receive their final pruning until March.