Vines are among the most versatile plants in the garden. They have a decidedly vertical habit as they reach for the sky, yet are easier to shape and manipulate than most trees and shrubs. Plus, they don't take up a lot of planting space. Gardeners use vines a number of ways: to hide a wall, downspout, or post; cover an arbor; crawl along an unsightly fence; or scramble up a trellis. Whatever your choice, be sure to pick the right vine for the job-each vine grows differently and is naturally suited for different purposes.
Twiners twist their entire stems up a support as they grow. Some twining vines prefer to grow in a counterclockwise fashion (for example, Chinese wisteria); others circle their props clockwise (honeysuckle vine). Don't try to train a vine to grow opposite to its natural habit. Because of their twining habit, these vines grow best on poles or fences; they won't grow on a wall by themselves.
Examples of twining vines include wisterias (Wisteria spp.), hops (Humulus lupus), many jasmines (Jasminum spp.), black-eyed Susan vine (Thunbergia alata), and morning glories and moonflowers (Ipomoea spp.).
Tendrils are specialized leaves that look like little stems. When a tendril encounters a support, it wraps itself around the structure and pulls the vine closer to it. Some tendrils grow individually; others branch almost like little hands. Vines with tendrils grow just about anywhere they can grab onto something, though they're not suited for flagpoles or similar structures because tendrils have difficulty grabbing large objects.
Examples of tendril climbers include passionflowers (Passiflora spp.), gloriosa lilies (Gloriosa spp.), sweet peas (Lathyrus spp.), and garden peas (Pisum sativum).
Holdfasts are a specialized form of tendrils. Instead of simply reaching and wrapping around, these tendrils have small discs at the tips. When the disc meets a structure, it adheres, allowing these vines to climb flat walls. These vines grow just about anywhere; for example, they're good choices for covering a chainlink fence.
Boston ivy (Parthenocissus tricuspidatus) and Virginia creeper (Parthenocissus virginiana) both bear holdfasts.
Leafstalks (technically called petioles) act like tendrils, except they still attach a leaf to the main stem of the plant. Some plants actually use their leafstalks to grab onto a structure. These vines tend to climb best over other shrubs or vines-for example, a clematis growing on a rose bush-or on trellises and arbors. They tend not to climb walls without additional support.
Examples of this sort of climber include clematis (Clematis spp.), canary creeper (Tropaeolum peregrinum), and temple bells (Rhodochiton spp.).
Roots that grow out of the sides of the stems of some vines (called "aerial roots") grow sideways into a structure, much like a regular root would grow down into the ground to provide the plant support. These vines also climb walls, though their roots can cause damage as the roots insert themselves into small cracks.
Ivy (Hedera helix), climbing hydrangea (Hydrangea anomala petiolaris), philodendrons (Philodendron scandens), and creeping figs (Ficus pumila) all bear aerial roots.
Supports for vines should be carefully selected to save future maintenance. First, the support must be strong enough to hold the vine you choose-wisteria, for instance, can grow more than 30 feet. A vine this size could easily crush an arbor that's too small for it-especially when it's windy or the leaves are wet and extra-heavy.
Second, the support needs to match the vine in terms of the way the vine climbs. Tendril climbers and twiners, for instance, can't scale a sheer wall-they need to grab hold of something. Likewise, a vine with aerial roots might have trouble growing up a metal pole because the roots won't have anything to grow into.