If you're trawling garden centres and nurseries looking for a real Christmas tree, there are certain things you have to bear in mind.

Size matters - it's no use trying to fit a wide, dense tree into a narrow space or hoping that a thinner tree will fill a huge space.

If you're on a budget, you may bag a bargain tree - Aldi will be selling Nordman firs up to 110cm (3ft 6in) for £11.99 from December 6 and taller Nordmans (up to 180cm/5ft 9in) for £19.99, against steeper prices from higher end retailers.

If you're worried about the carbon footprint and imported trees, you may be better off going to members of the British Christmas Tree Growers' Association (www.bctga.co.uk) for a tree grown in the UK.

Wyevale Garden Centres (www.wyevalegardencentres.co.uk) also sources the vast majority of its trees from the British Isles.

"The Nordman Fir is our most popular tree and is much more needle-fast with attractive dark colouration," says David Mitchell, plant buyer with the group.

"Those looking for something more exclusive and unusual may go for the Fraser and Noble firs which have an almost conical shape, tasteful blue or olive green colours and both with very dense, highly scented foliage."

There's been a trend towards 'Swedish-style' trees that have a much more open structure where you can visibly see the layers and lay decorations right into the centre.

"This does come in at a lower price point but is by no means a lower-quality tree - it follows the trend for a more modern Christmas tree that suits minimalistic and contemporary spaces and modern decoration themes," says Mitchell.

The traditional Norway spruce is less popular but is cheaper, smells good and represents the classic idea of a Christmas tree from childhood. The blue spruce is all about the colour and is ideal as a pot-grown tree, to be kept after the festivities.

Mitchell offers the following top tips for choosing and looking after your tree:

:: Choose a tree that isn't pre-wrapped in netting so you can really see the shape and the branches won't permanently be stuck upright. Plus, if trees are left in the net, air is not able to circulate, the tree warms up and a micro-climate forms. This leads to the tree beginning to decompose and needles will drop at a much quicker rate.

:: The colour of the needles should be dark green, not pale and washed out, and needles should feel waxy to the touch and not dry. Try stroking the tree and seeing if needles come off.

:: Some people prefer a full dense tree, others opt for a more open shape but in general, the tree should be evenly proportioned, not too dense at the bottom or sparse at the top or have gaping holes. Make sure you look around the whole tree for these.

:: The top of the tree is important. Look for a straight leader (the long, tall part of the tree, right at the top).

:: When first brought home, keep your tree fresh for longer by chopping a few centimetres off the bottom and soaking it in a bucket of water outside at least overnight, but for as long as possible before bringing indoors.

:: Keep the tree away from draughts and direct heat and ideally use LED lights, which emit less heat and are better for the environment.

:: Don't wait until the last minute to purchase. Christmas trees are cut at broadly the same time in the fields in late October/November so if you buy late, the trees are likely to have been in a stored location for a long period out of water and receiving no care, which may result in them not lasting as long.

BEST OF THE BUNCH - Fern

They are perfect for shady spots and will grow in most soils, but dwarf ferns such as Asplenium scolopendrium can also add texture and form to winter containers. Select evergreen types in a variety of colours and textures to create a mini fern garden in old sinks or large planters, or add types such as the male fern (Dryopteris filix-mas) next to euphorbia and heuchera for a beautiful combination. Very few ferns need constantly moist conditions and most hate being waterlogged, but make sure you add plenty of organic matter before planting and if you have heavy soil, add plenty of grit to the planting hole to help drainage around the crown. Ferns can be grown in the border, or as ground cover in dappled shade, although don't put them next to shallow rooted trees like large conifers which will dry out the soil.

GOOD ENOUGH TO EAT - Protect fruit trees

Many gardeners will now be planting new fruit trees and bushes, but it's also important to keep your established fruit trees healthy and protected from pests over the winter months. Don't delay putting grease bands around the trunks and stakes of fruit trees, which will trap winter moths. The bands should be about 45cm above ground level and secured there until April. If you have older trees with rough bark, apply paint-on grease to stop wingless female moths climbing up the tree to lay their eggs. This will result in the hatching caterpillars attacking the leaves.

WHAT TO DO THIS WEEK

:: Plant lilies in patio pots, keeping them in the greenhouse to develop.

:: Create an inexpensive hedge by taking hardwood cuttings and inserting them directly into the growing site.

:: Prune autumn-flowering shrubs over three years old as they finish flowering.

:: Drain surface pumps in the pond and have them serviced if necessary. Alternatively clean, dry and grease before storing.

:: If you haven't already done so, put a layer of sharp grit on the surface of your rockery to stop alpines becoming waterlogged.

:: Pot up cyclamen sown in late summer for a good show next year.

:: Clean gladioli which were lifted and tied in bundles or placed in boxes to dry in the autumn. Force the old corm from beneath the new with your thumb nail, pull off the dried leaves and story in a dry, frost-free place.

:: Lift rhubarb crowns which you intend to force and leave them exposed to frost for two weeks before bringing them in to the glasshouse or shed. They can then be packed in boxed using soil, watered and then blacked out.

:: If you have climbers, check your guttering and cut back anything blocking it.

:: Pick over winter-flowering pansies regularly to remove faded flowers.