You might think that gardeners, being the wonderful, nurturing folk we are, would be less inclined to fall slave to fashion, but no. Each year, gardeners by the million kneel (naturally enough) and worship the latest trends. Thank goodness we do: new plants are garden bling, the spice of the game, and if no one bought them, then no one would breed them and gardens would be all the poorer for it. So what will the well-dressed garden be wearing in 2008?

There are plants that spend years doing the provincial circuit of private plantsmen’s gardens before they burst on the scene and make it big time. They play the Edinburgh Fringe in Penelope Hobhouse’s garden, they have their own pre-West End tour – the National Garden Scheme stage – and then, all of a sudden, there they are, desired by all on the red carpet at Chelsea.

This year, the star will be Mathiasella. The name sounds oddly like a glam gospel singer, I know, but it’s actually a plant in the carrot family, and like many a trendy plant, it’s jade green – one of life’s great mixers. To be precise, it’s called Mathiasella bupleuroides ‘Green Dream’, a Mexican with drooping clusters of bells on a loose, waist-high stem, and showing seductively more flower than leaf. Sun and sharp drainage, please. Try it and see.

There’s been a string of black plants in recent years such as Phormium cookianum ‘Platt’s Black’. But now, making it big at last, is the black taro, Colocasia esculenta ‘Black Magic’, a luscious foliage plant to put in hot, moist corners of the garden in the company of other exotics; show it a banana and it weeps. Another one to try, but keep it dry indoors for the winter.

51 glorious garden websites

Times Online's gardening guru opens her address book to share her top pick of gardening websites

Related Internet Links

• A ten step guide for novice gardeners

• The gardening year planner - what to do, when

• Guides for vegetable growers

BACKGROUND

• A gardener's guide to healing herbs and flowers

• Fruit bushes: what to grow and how to get a good crop

• Plant it now: a beginner's guide to snowdrops

• Neil Wormald’s week: a potted guide to growing chillies

• A guide to making a great patio garden

BACKGROUND

• A year in the garden: tasks for every season

• How to start a vegetable garden

• Twenty vegetable catalogues

• Eight great vegetable gardening books

BACKGROUND

• Growing kinds of chilli. . .

• Go ahead, pack it in

• Seeds of change

• Dolce vita on a plate

• Salad days that last forever

BACKGROUND

• Let’s not lose the plots

• A plot on the land

• Seeds of change

• There's life in the allotment

• One potato, two potato...

Related Links

• Garden cuttings

• The rural consultant

Good things are happening on the bulb front. The indoor amaryllis (Hippeastrum) is fast becoming a common cut flower, so there’s less need to grow it as a pot plant – no more lamppost stems, leafless bulbs and no leaves at all through the autumn. But newcomer Hippeastrum papilio is a different kettle of fish. The flowers are a complicated streaky green and claret on more slender stems, and the dark green leaves last all year. It’s insidiously beautiful and it’s in garden centres at last. And if you like it, look out for the new H. cybister with flowers somewhere between H. papilio and Charge-of-the-Light-Brigade reds.

A bulb arriving with a bang and in lots of new varieties is the South African pineapple lily, Eucomis. The maroon-leaved variety, Eucomis comosa ‘Sparkling Burgundy’, has been around for a year or two, but try the others, too. They are dubbed “tender”, but don’t mess about growing them in pots; just plant their noses 6in below the soil and they’ll be fine. They are cheap now as well: I got a clump of six monster bulbs of E. pole-evansii from the RHS Cardiff show this year for a fiver. Half shade and moist soil.

This year’s ingénue must be Dianella, a leathery, strap-leaved Tasmanian, rather like a narrow-leaved iris, but grown for its blue flowers and amazing blue berries. Gardeners are for some reason obsessed with blue berries – think of Clerodendrum and Callicarpa bushes – and here they are on a perennial. Give her humus-rich woodland soil and shelter. Also due to arrive in style this year is new dogwood Cornus kousa ‘Venus’. If you think you have seen one with big flowers, wait until you see this – they are almost 6in across and really plentiful. An amazing big shrub or small tree for acidic soil.

But if you want to be fashionable rather than gaze at designer plants, then forget about new ornamentals and grow vegetables. The sale of vegetable seeds for growing your own continues to rise at an astonishing rate, while general plant sales actually fall, proving that everybody is out there having a go.

Fashionable colours for 2008? The past few years have taken us from the peach of Verbascum to the mauves of alliums and verbena and to the reds and purples of cannas and dahlias. We have had the blue, orange and yellow of the cornfield. So what’s next? I see pastels finally returning from the wilderness to which they were banished. Cool will begin to be cool once more.

New building materials? Walk down any suburban street on a still night and, if you are very quiet, you will hear the sound of decking quietly rotting (sales are collapsing); Indian sandstone’s now the thing. It’s relatively cheap and we want to afford stone now. Marshalls, which sponsors the Chelsea Flower Show, imports Indian sandstone as well as making concrete slabs here, and last year the company made a great to-do about how, unlike other importers, it doesn’t use poorly paid child labour to produce it. Does that make it the more palatable product of the two for eco-gardeners, then? Well, the company says that, despite the manufacturing process, concrete still has the smaller carbon footprint. So which will you choose, O Sustainable Gardener, concrete or sandstone?

New gardens arrive on the scene just as do new plants. Everybody I know seems to have been to the Old Zoo garden near Blackburn this year and its reputation is ready to soar. Cherkley Court in Surrey is a garden to watch. Home of newspaper proprietor Lord Beaverbrook, it opened this year for the first time. There is a fine shell grotto. Good things are going on at Sheffield Botanical Gardens, too; with £5 million of lottery funding, it is turning from a sad relic into a great delight, and the range of glasshouses is fabulous. Make a note in your diary and get out to see them.

Sheffield Botanical Gardens (0114-268 6001; www.sbg.org.uk). The Old Zoo, Brockhall, Lancashire (01254 244811; www.theavenuehotel.co.uk or www.ngs.org.uk). Cherkley Court, Leatherhead, Surrey (01372 380980; www.cherkleycourt.com).

You can get Mathiasella bupleuroides ‘Green Dream’ from Cotswold Garden Flowers, Worcestershire (01386 422829; www.cgf.net ), and it should be more widely available in the spring

Explore Gardens

• Hampton Court Palace Flower Show

• Chelsea Flower Show

Times recommends

• Second homes: credit crunch casualty or money-spinner?
• How I built my own sliding house
• Top 10 incentives for house buyers