A trellis is a supportive framework designed to encourage vertical plant growth, allowing gardeners to utilize space efficiently and add a dynamic, three-dimensional element to landscapes. Elevating foliage off the ground promotes better air circulation, which reduces the incidence of fungal diseases. Trellises also provide an aesthetic backdrop, transforming a flat wall or fence into a lush curtain of greenery. Selecting the right plant requires understanding its specific climbing method, as this mechanism must be compatible with the trellis design.
How Climbing Plants Attach to Structures
Climbing plants have evolved distinct biological strategies to ascend vertical structures, and these mechanisms dictate the type of support they need to thrive. Twining vines use their main stem or shoot tip to grow in a circular motion (circumnutation) until they contact a support. The stem then coils tightly around the structure in a helical pattern. This method, common in species like pole beans, is highly effective on poles or ropes but struggles on wide, flat surfaces.
Tendril climbers utilize specialized, slender appendages, often modified leaves or stems, to find purchase on a support. When a tendril touches an object, it wraps around it and coils into a spring-like helix, absorbing tension from wind. Plants such as grapes and cucumbers rely on this mechanism, requiring a trellis with many small, horizontal grab points, such as netting or thin wire. Clematis uses a specialized form, twining its leaf petioles (leaf stems) around supports, requiring structures no thicker than about three-quarters of an inch to grasp securely.
A third group consists of clinging or adhesive climbers, which employ aerial rootlets or disc-shaped adhesive pads to attach directly to flat surfaces. English ivy uses stiff rootlets that penetrate crevices, while Virginia creeper uses tendrils tipped with strong adhesive pads. These mechanisms allow tight adherence to walls or wood, but they can cause damage to paint or mortar upon removal. Finally, scramblers or hookers lack self-climbing structures and rely on stiff canes, thorns, or hooked prickles to lean against a support. Plants like climbing roses are not true climbers and require gardeners to manually tie their long canes to the trellis for vertical positioning.
Recommended Climbing Plants for Trellises
Selecting plants based on their mechanism ensures a successful match between the vine and its support structure, allowing for ornamental beauty or edible yields. For flowering displays, Clematis is a popular choice, providing a dense cover of blooms ranging from deep purple to white. Since Clematis vines climb by twining their leaf petioles, they perform best on trellises made of thin wire, twine, or narrow lattice slats they can easily wrap around.
Climbing Roses offer fragrant, large-scale drama, but as scramblers, their woody canes must be physically secured to the trellis using soft ties. To maximize flowers, the main canes should be trained horizontally or at a 45-degree angle along the supports, encouraging lateral flowering shoots. For rapid, temporary cover, annual vines like Morning Glory are vigorous stem twiners that quickly spiral up poles or thin supports, producing trumpet-shaped flowers. Honeysuckle is another vigorous twining perennial, prized for its sweet, tubular flowers that attract pollinators.
For edible gardening, many vegetables and fruits are adapted to trellising, offering increased productivity in a smaller footprint. Pole Beans are classic stem twiners that rapidly coil upward, producing an extended harvest and requiring only a simple vertical pole or string. Cucumbers and certain varieties of Squash use sensitive tendrils to grip and ascend supports. Growing these vertically improves air circulation, prevents powdery mildew, and keeps the developing fruit clean and easier to harvest. Grapes are reliable climbers that use woody tendrils to anchor their heavy vines, necessitating a sturdy arbor or robust trellis to support the mature plant and fruit load.
Matching Plants to Growing Conditions and Maintenance
Successful vertical gardening depends on matching the plant’s environmental requirements and the necessary maintenance. The trellis location must be assessed for sun exposure, as most flowering and fruiting climbers require at least six hours of direct sunlight daily. However, plants like Clematis prefer their foliage in full sun while their root zone remains cool and shaded, often achieved by planting low-growing perennials or applying thick mulch. Choosing a plant hardy for the local climate—either an annual that must be replanted or a perennial that returns yearly—is a fundamental decision.
Perennial vines, such as Clematis or Climbing Roses, establish a permanent structure and require regular pruning to control size and encourage flowering. Climbing Roses benefit from major canes being trained horizontally and tied securely to the trellis, ensuring maximum bloom production. Annual vines, like cucumbers and morning glories, offer a temporary, fast-growing solution but must be completely cleared from the trellis at the end of the season.
The climbing mechanism dictates the level of training required; stem twiners and tendril climbers are largely self-sufficient once they find support, whereas scramblers must be actively tied and guided. The longevity and material of the trellis should also be considered in relation to the plant’s vigor. Aggressive root-climbers, such as English ivy, should be avoided on delicate wooden structures or house siding. Their permanent attachment methods can cause structural damage, necessitating a robust or metal support system.