Now is the best time to plant, but be sure to pick the right type

If you're looking for a plant to provide privacy from neighbours, act as a focal point or add vertical interest, then snap up a tree - those planted now will establish quickly in moist soil, forming roots that will enable them to romp away in spring.

There are masses of trees on offer at garden centres and nurseries at this time of year. Many will be sold as container-grown specimens, but you'll also find bare-root trees. Generally cheaper to buy, these trees are two to three-year-old plants grown in a field and lifted for sale while dormant.

Yet choosing the perfect tree can be tricky. Many are one-season wonders that you'll soon tire of as they do little to earn their keep during the rest of the year.

But among those worth growing are crab apples - this large tribe of small trees, known botanically as malus, boast glorious scented blossom in spring and branches laden with showy fruit during autumn and winter.

Malus 'John Downie' has white flowers followed by orange fruit, while M. x zumi var. calocarpa 'Golden Hornet' is blessed with pink blossom and tiny yellow apples. M. tschonoskii has white flowers and chartreuse fruit, and its leaves turn yellow, orange, purple and bright red in autumn.

Ornamental cherries are probably the most exuberant of spring-flowering trees, but many fail to turn heads once the blossom starts to fade. Not Prunus cerasifera 'Nigra' - the clouds of pink flowers that form on bare branches are replaced by a cloak of purple foliage. Another winner is P. sargentii, a roundheaded tree with pink flowers, striking autumn colour and attractive bark.

There are many fantastic varieties of sorbus, which will reward you with flowers in spring, handsome foliage, jewel-like berries and fiery autumnal tints. Sorbus vilmorinii is desired for its white flowers, ferny foliage and pinkish berries, while S. 'Joseph Rock' has bright yellow berries and leaves that turn shades of orange, red and purple. My favourite is S. cashmiriana, a small tree with pink flowers, graceful foliage and pure white berries that remain on branches well into winter.

Other hard-working varieties include Pyrus calleryana 'Chantiguide cleer', a slender tree with white flowers and glowing autumn foliage, and Amelanchier lamarckii - apart from spring flowers and black fruit, its green leaves turn crimson later in the year.

Whichever sort of tree you choose, avoid planting too close to your home: some have roots that can disrupt foundations, damage drains or lead to subsidence. Willows, poplars, oaks and other vigorous species need planting up to 65ft from buildings, while a gap of 12ft to 23ft is fine for smaller specimens. A useful to planting distances can be found at www.subsidencebureau.com, but as a general rule, roots cover a distance that's equal to twoand-a-half times the mature height of the tree.

Planting a container-grown tree in the ground does not take long but it's essential to do it correctly or it may fail to establish. Start by preparing the site. Skim off any weeds with a hoe, then dig a round hole that's about twice the diameter of the container and the same depth.

Spike the sides and bottom of the hole with a garden fork to allow roots to penetrate easily. Stand the tree in a bucket of water for a few minutes to ensure roots are damp, then slide off the container and tease out roots from the side and bottom. Place the tree in the centre of the hole and backfill with the excavated soil, firming it down with your hands to remove air pockets.

Bare root trees need planting at the same depth as they were growing before being lifted from the ground - there should be an obvious 'tide mark' of soil on the trunk.

After planting, give the soil a good soaking, then spread a 3in layer of bark, leaf mould or garden compost over the surface to lock in moisture and prevent weeds growing. Keep mulch clear of the trunk as contact can cause bark to soften and rot.

Any trees over 3ft will need shoring up. Use round or square tree stakes hammered into the ground vertically for bare root tree and stakes at 45 degrees for containergrown trees. Secure to the tree with plastic buckle ties.

Slow-growing or compact trees can be planted in large pots. First, cover the drainage holes in the base with bits of broken terracotta pot, then add a layer of soil-based John Innes No3 compost. Mix in some slow-release fertiliser granules. Place the tree in the pot and top up with more compost. Leave a 2in gap between the surface of the compost and the lip of the container to allow space for watering.

Keep compost moist and feed each spring. To do this, carefully scrape away loose compost from the surface and replace with fresh compost and a handful of fertiliser granules. Most trees will be happy in the same pot for up to five years but will eventually start to sulk when the roots run out of space. Pep them up by transferring to a slightly larger container.