There's a nip in the air which, to me, signals the end of summer and provides a wake-up call to start planting some spring bulbs to brighten up borders and patios next year.

Yet the wealth of varieties on offer, from crocus and dwarf narcissi to fragrant hyacinths and majestic tulips, can leave many gardeners wondering what to choose.

Suppliers are constantly trying to help customers select the best combinations. Suttons (www.suttons.co.uk), for instance, has a range called 'Plant-O-Mat', pre-planted bulbs inserted in individual compartments in a biodegradable tray. You just dig a hole, put the tray in and cover it with compost. The range features a number of combinations, colours and sizes. They also cater for window boxes and containers.

If you want something different which is going to stand the test of time, Gardening Which?, the Consumers' Association magazine, has recently trialled a number of new bulbs to see how they fared.

Researchers found that some new varieties will flower more consistently and for much longer than many older varieties.

Last autumn, triallists chose 50 newly bred varieties of spring-flowering bulbs and grew them alongside five well-known varieties - daffodils 'Delnashaugh' and 'Dutch Master', and tulips 'Ballerina','Mount Tacoma' and 'Red Riding Hood' - for comparison.

Bulbs were planted in October: hyacinths 15cm deep, narcissus twice their own depth and tulips at three times their own depth. In spring, the bulbs' development was monitored, when they flowered, how long they lasted and their sizes, colours and scents.

In the latest batch of testing, researchers noticed a lot of colour-changing varieties (such as tulip 'Caribbean Parrot') with flowers that open in one colour then change to another as they age, adding a new element of interest.

New daffodils which came out on top included 'Ferris Wheel' (youtulip, www.youtulip.co.uk), a large bright yellow variety which grows to 40cm and produces immense trumpets with a frilly rim, flowering in April for around three weeks.

A more subtle variety whose flowering period lasted up to 32 days was 'Beautiful Eyes' (J Parker's, www.jparkers.co.uk) which has small, straight stems holding clusters of two or three creamy flowers with yellow centres and gives off a heady fragrance.

Tulips recommended included 'Mistress Mystic' (Spalding Plant & Bulb Company, www.spaldingbulb.co.uk), a pink goblet-shaped flower which grows to 60cm and looks ideal in the middle of a border, and the zingy 'Caribbean Parrot' (Thompson & Morgan, www.thompson-morgan.com), which lasted much longer than any other parrot-type tulip in the trial and looked wonderful in a pot. Its most impressive feature, though, was its colour-changing flowers - which started mainly yellow, but deepened as they aged, until eventually they were almost completely red.

Among the top-performing hyacinths was 'Pink Angel' (Bloms Bulbs, www.blomsbulbs.com), whose brightly coloured flower spikes were much larger and better formed than any of the other varieties, with a fantastically potent scent. Unlike the other hyacinths grown in the test, they managed to stay bolt upright throughout the trial - essential if you're going to use them in the garden, although they looked good in pots too.

:: The full report is in the latest edition of Which? Gardening. Sign up to Which? for a one-month trial for £1 and get access to all its product reviews, test scores and Best Buy or Don't Buy ratings. Visit www.which.co.uk/signup for more information.

Best of the Bunch - Dahlia

For a while they went out of fashion, but today there's a different variety of dahlia for every taste, whether you want huge, soft blousy flowers, or slightly spiky cactus ones, with foliage ranging from rich green to burgundy/black. The beauty of dahlias is not only their colour, but also the fact that they are among the most impressive of the late-summer blooms and many are ideal for cutting. Take D. 'Weston Pirate', a deep-red variety which blooms into October and looks fabulous in a mixed flower border, producing masses of cactus-type flowers. Or there's D. 'Pam Howden', an easy-to-grow type which doesn't need staking and produces stunning water lily-style flowers in subtle apricot hues, while the black leaves of D. 'Magenta Star' contrast brilliantly with its bright pink flowers. Dahlias like to be grown in a sunny spot in rich soil, which has been enhanced with compost before planting. They are tender perennials so need lifting and storing before winter sets in.

Good Enough To Eat - Peppers

With the sunshine and warm weather, many growers are enjoying delicious peppers from their vegetable gardens and containers earlier than they would normally. Almost perfect growing conditions during July and into August have ensured plants on seed and plant company Mr Fothergill's Suffolk trial ground have made more rapid growth than they have seen for years. Peppers should be sown in a heated propagator on a windowsill indoors in spring and then pricked out and grown on at 16-19C, then put outside in a sunny, sheltered spot in early to midsummer and hardened off, as they are frost-tender. They should be fed weekly with liquid tomato feed after the first flower opens to encourage plenty of fruit. Plants should be supported by tying the main stem to a cane. If you want red peppers, leave the green ones to ripen.

What To Do This Week

:: Bring in house plants that have been standing outdoors in the summer, before they succumb to cooler weather.

:: Plant daffodil bulbs, which begin their root growth earlier than most bulbs.

:: Plant out spring-flowering biennials including wallflowers and forget-me-nots in their flowering positions.

:: Store apples and pears for use over the winter.

:: Continue to pick sweet peas to encourage further flowers.

:: Plant dwarf bulbs such as crocus in lawns and grassy banks and scillas and chionodoxas in pots.

:: Protect the ripening fruit of plums and cherries from birds and squirrels. Pick the fruit as it becomes ripe but watch out for wasps when picking.

:: Visit dahlia shows to identify new varieties you'd like to grow.

:: Lift and divide five-year-old clumps of perennial herbs such as bergamot and lemon balm, discarding the old woody centres and replanting in new positions.

:: Reduce watering orchids indoors as growth slows down and apply the last feed. From the end of September until next April no feeding is necessary.