By Joel M. Lerner, APLD
Special to The Washington Post
WASHINGTON - Vines can be trained onto almost any structure - deck, porch, shed, pergola, wall, fence, pole or arbor. The type of climber being trained determines how it should be attached. Plants climb in different ways:
• Aerial roots. Ivy and trumpet vine have adventitious, also called aerial, roots that will attach to any solid wall without training. If you plant ivy or trumpet vine on a trellis with an open framework, tie it to the supports until it self-attaches with rootlets from its stem onto the vertical support it is against. English ivy is actually a woody shrub that strives to grow vertically by means of aerial roots. As it grows up a tree, it changes from juvenile (lobed leaves, no fruit) to adult (no lobes on leaves, flowers and fruit that birds love to eat and spread through the woods).
• Twining. Some plants twine around other objects they come into contact with. Clematis, morning glory, honeysuckle, kiwi (Actinidia kolomikta) and wisteria will train themselves onto anything. The challenge is keeping them under control. These vines can kill a tree or shrub by entwining too tightly around it.
• Tendrils. Plants such as the grape have spiral, springlike stems called tendrils that curl around wires and other narrow supports. Tendrils of beans and peas grow from leaf stems and curl around wires and poles in the same way grapevines do. They will train themselves onto an arbor or over lattice.
• Tendrils with modified connectors. Some vines, including Boston ivy (Parthenocissus tricuspidata) and Virginia creeper (P. quinquefolia), have modified connectors at the end of each tendril called discs that attach to a structure with a type of natural glue. They prefer solid structures such as walls and trees.
Shrubs that aren't natural climbers can be trained on trellises. The best ones are vigorous growers that will take hard pruning and dependably renew. Roses and pyracanthas can be trained as climbers. Pruning keeps them tightly against trellises and full of flowers, fruits or berries. Shrubs you train should have interesting leaf color, berries, flowers, branching habits or other outstanding characteristics.
Trellising plants and keeping them narrow are excellent approaches for tight spaces. The practice of training shrubs and trees on trellises is called espaliering. It was developed by the French as an intensive gardening practice to stimulate fruit production in small areas.
To train a shrub or tree, prune the front and rear growing branches and leave only desired side branches. Leave three- to six-inch stems coming off main branches so there are buds to produce flowers and fruit. The time to prune depends on the plant. Most should flower or fruit before being pruned.
Here are some suggestions for planting tough vines:
• Boston ivy. New growth emerges maroon in spring. A fast grower in sun or shade, it will cover walls in a season or two. Green summer foliage is excellent background for water features, sculptures or other plantings. Fall color is an outstanding red.
• Clematis. I can't recommend just one. Red, purple, pink and white five- to six-inch flowers grow profusely in late spring on the jackman clematis. The anemone clematis (C. montana) grows vigorously to cascade over fences, walls or trellises and is covered with white to pink flowers in May. Sweet autumn clematis runs rampant over any plant or structure and can become almost weedlike, but doesn't need a heavy support. Lacy white, fragrant flowers open in fall.
• Climbing rose. There are many hybrids of climbing roses, in miniature and full size forms. There are two we have grown for years. Aloha is planted between two structures, receives about six hours of light and is self-sufficient. Another one that needs little care is zepherine drouhin, which is free of thorns. At least two flushes of pink flowers are produced per season on both.
• Everlasting or perennial sweet pea. This hardy vine produces flowers of deep pink to purple, summer and fall. It will cover a six-foot trellis in a season. It features wide-winged stems. Freezes back in winter.
• Lerner is president of Environmental Design in Capitol View Park, Md., and author of "Anyone Can Landscape" (Ball 2001). Contact him through his website, www.gardenlerner.com.