TRELLISES BRING architectural interest to a garden or house, while the plants that climb up them add beauty, color and fragrance. Climbing plants can scale walls, ramble over pergolas, wind around tree trunks and scramble up trellises. They are both impressive and versatile - and there's room for them in every garden. Here are some ideas for incorporating them into yours.Trellises and climbing plants

No garden is perfect, and climbing plants can solve problems: Use them to camouflage unsightly walls or fences or to turn an old tree stump into something quite lovely.

A freestanding trellis can section off one area of the garden from another, creating "rooms" in the garden (or hiding the compost pile).

Climbing plants are a creative solution for a too-small garden. They offer a new sense of dimension - verticality - to the setting. They can create a shady, private hideaway when grown over a structure such as a pergola. And fast-growing annuals can make a garden seem established, even if it's new.

At my home in East Hampton, N.Y., two trellises stand at opposite ends of the garden: One is a series of curved arches, the other a rectilinear arch. They make the garden seem much more expansive. Roses and wisteria wind around them in the summer, but I appreciate them even in winter when they lend a sense of shape and focus to the landscape.

Less-permanent "tepee trellises" can be fashioned from bamboo poles, available at garden-supply shops. Tie three or four 5-foot poles together a few inches from one end using twine. Separate the poles at the other end, forming a tepee shape. Push the poles directly into the soil, or start holes first if necessary. Morning glories and other annual vines will be happy to clamber up them.

What makes plants climb?

Some plants, like ivy, are self-clinging, which means that they attach to a wall with the holdfasts they have on aerial rootlets or modified leaves. Others, like clematis, are twining plants; these have long stems or tendrils that wrap around the support as they grow.

Climbing and rambling roses aren't technically climbers at all: They have neither holdfasts nor tendrils and must be woven through a trellis or tied to a support. With this encouragement, however, they act like climbers, and do so beautifully.

A few favorite climbers

The classic climbers are roses, clematis and wisteria. Other wonderful perennials include honeysuckle and trumpet vine, Campsis radicans, with large blooms that are usually orange. Both of these attract hummingbirds.

Two vines worth planting for their leaves alone include the hardy kiwi vine, Actinidia kolomikta, with green leaves splashed with pink and white, and the vibrant golden hops, Humulus lupulus "Aureus."

Perennials will serve you well for years - but they may take a few to come into their own. In the meantime, consider planting annual vines (or perennials that are treated like annuals), which let you change your color scheme from year to year.

Morning glories, Ipomoea purpurea, are easy - and quick - to grow, as are their fragrant, night-blooming relatives, moonflowers (I. alba).

Cup-and-saucer vine, Cobaea scandens, has purple or white cup-shaped blooms. The climbing snapdragon, Asarina antirrhinifolia, has delicate red or purple tubular flowers. Canarybird vine, Tropaeolum peregrinum, a climbing nasturtium, has blue-green leaves and bright yellow flowers.

The whimsical balloon vine, Cardiospermum halicacabum, is a real charmer; also called love-in-a-puff, it has black seeds marked with a white heart inside bright-green balloons, and pretty chartreuse leaves and tendrils.

A few helpful tips

- It's important to match the plant to its support and space. Wisteria really needs a sturdy metal structure, and roses require either metal or a reinforced heavyweight wooden base; they'll pull down anything else. Make sure there's enough room for the plant to grow as it matures.

- If the plants need a little help, tie stems to their support with cotton string, strips of cloth or twist ties. But don't bind tightly, or you'll damage them.

- A trellis looks great against the wall of a house but shouldn't be flush up against it. A few inches between the wall and trellis lets air circulate, which is beneficial for the plants and, even more important, the house: Plant life can rot and damage woodwork.

If you install a trellis with hinges at the bottom or hardware that can easily be removed, you'll be thankful when it's time to paint the house - just lower the trellis, plants and all.