THERE'S NOTHING LIKE a climber to give your garden a vertical accent. I like flowering ones, whether annual or perennial. The first annual I sow in spring is the sweet pea. The seeds can be sown outdoors in May while nights are still frosty. I plant morning glory seeds a few weeks later. I soak both types of seed overnight in cool water. For earlier flowers, sow them indoors three weeks before planting. Easy-to-grow alternatives include scarlet runner beans, climbing nasturtiums, balloon vine (Cardiospermum) and canary vine, a yellow flowering nasturtium relative. My favourite tender perennial is Mandevilla (formerly known as Dipladenia), with spectacular and fragrant pink, red, yellow or white flowers on fast-growing woody vines. This tropical is expensive in garden stores in the spring, but worth it. Grow it as a hanging plant, or let it twine up any slender support in full to part sun. Water and feed it regularly in summer. Bring Mandevilla indoors before the temperature dips to 5 degrees Celsius. It will go dormant if kept dryish in a cool place with natural light. In late spring, move it to a sunny window, prune it almost to the ground, and water and feed it well before gradually reintroducing it to the outdoors. The clematis is a flowering vine that makes me wish I had more walls. Among the hardiest, to Zone 3 and sometimes 2, are small-flowered species that may self-sow and thus can even be grown from seed. My C. ligusticifolia 'Prairie Traveller's Joy,' blooms in late summer. Its small white flowers produce fluffy seedheads. I've had occasional seedlings to give away. Clematis needs help finding the trellis, where it will hang on with its leaf stems. Once attached, it needs only a little encouragement. For bright pink flowers, consider C. macropetala 'Rosy O'Grady,' for blue, the aptly-named C. macropetala 'Blue Bird,' and for bright yellow, C. tangutica. All are on the seed list of the Devonian Botanic Garden, www.devonian.ualberta.ca. Purple C. jackmanii and deep pink Clematis 'Ernest Markham' yield larger flowers and thrive without winter protection in my Zone 4 garden. I prune clematis only when it becomes too big or leggy. C. macropetala blooms on last year's wood, so prune it when the seedheads form. The others I've mentioned bloom on new wood, so can be cut back in late fall or early spring. Last spring, I worked at a garden nursery, where the most sought-after hardy climber was the rose. Fortunately, breeding programs in northerly places have yielded climbing roses hardy to Zone 3. The best are also disease resistant, including two of Agriculture Canada's Explorer series, the dark pink 'William Baffin' and the slightly paler 'John Cabot.' Both can grow three metres (10 feet) tall. Initially, climbing roses require extra protection. In the first fall, after frost, lay them flat and cover with soil and mulch. Thereafter, they should survive winters without protection in full or partial sun and good, well-drained soil. In spring, prune damaged or dead stems and apply rose fertilizer to speed recovery. To discourage fungi and pests, drench plants with a spray made from a spoonful each of baking soda and dish soap per litre of water. Mandevilla and the annual vines will climb on temporary supports, but perennials require sturdier wooden trellises or fences. Position trellises an arm's length away from exterior walls, since the rain shadow under the eaves leaves plants thirsty. Consider the vines' eventual size, too: better a large trellis allowing additional climbers than a small one that topples. Some climbers will clamber over large stones or even climb the trunks of shrubs and trees - clematis does this beautifully. - JENNIFER BENNETT Jennifer Bennett welcomes feedback at jben@ca.inter.net or via acreagelife.editors@producer.com.