A trellis is a supportive framework that allows climbing plants to grow vertically. This structure is typically a lattice, mesh, or set of wires that lifts the plant off the ground, maximizing the use of limited space. Utilizing the vertical plane is particularly beneficial for urban gardeners and those with small plots. This approach improves plant health by increasing air circulation around the foliage, which helps reduce fungal diseases. Furthermore, growing plants upward ensures better exposure to sunlight, leading to vigorous growth and higher quality fruit or flower production.
Edible Plants for Vertical Growing
Training edible plants onto a trellis significantly increases a garden’s food production capacity while keeping the harvest clean and accessible. Annual vegetables that naturally climb are ideal candidates for this method, as their upward growth frees up valuable ground space for other crops. Pole beans and peas, for example, are prolific annual climbers that wrap their stems or tendrils around supports, yielding a continuous harvest throughout the growing season.
Cucumbers and indeterminate tomato varieties thrive when trellised, as keeping their leaves and developing fruit off the soil minimizes contact with pests and soil-borne pathogens. Even some smaller squash and melon varieties, such as ‘Tromboncino’ or mini-pumpkins, can be trained vertically. However, larger fruits may require individual support slings to prevent the weight from damaging the vines.
Perennial fruits offer a long-term solution for vertical food production. Grapes are a classic example, requiring a sturdy arbor or trellis to support their heavy, woody vines and substantial fruit load. Hardy kiwi vines are another vigorous, high-yielding option, often requiring a strong support system to manage their rapid growth and dense foliage. Cane fruits like raspberries and blackberries, while not true climbers, benefit from being tied to a wire trellis system, which organizes the canes, facilitates pruning, and simplifies the annual harvest.
Ornamental Climbers
Ornamental climbers are selected primarily for their aesthetic qualities, such as vibrant blooms, attractive foliage, or fragrance, adding a vertical element to the landscape. Flowering vines like Clematis are valued for their profusion of colorful, star-shaped flowers that can bloom in various seasons, depending on the cultivar. These plants use their leaf stems, or petioles, to grasp thin supports, weaving a dense curtain of blossoms.
Climbing roses and honeysuckle varieties are popular for their strong, sweet fragrance, which can perfume a garden or patio. Climbing roses need to be physically tied to a trellis, providing a classic, romantic look with their large, multi-petaled flowers. Honeysuckle is a twining vine that wraps its stems around a structure, providing rapid coverage and attracting pollinators like hummingbirds.
Other ornamental options focus on foliage and texture to create visual interest or provide screening. Star Jasmine is an evergreen twining vine prized for its glossy, dark green leaves and small, fragrant white flowers. Boston Ivy and Climbing Hydrangea are used for covering solid walls, using specialized root-like structures to cling directly to rough surfaces like masonry or wood. These foliage vines offer dense, long-lasting coverage, with some providing seasonal color changes in the autumn.
How Plants Attach to Supports
Climbing plants have evolved distinct biological mechanisms to secure themselves to vertical supports, and understanding these is necessary for choosing the correct trellis. One common method is twining, where the main stem or a specialized shoot spirals around a support structure. Plants like pole beans and morning glories use this method, which requires a support thin enough for the stem to fully encircle, typically less than one and a half inches in diameter.
A second mechanism involves tendrils, which are slender, whip-like appendages that coil tightly when they make contact with a surface. Peas, grapes, and passionflowers use these modified stems or leaves, and their tendrils are only able to grasp fine supports, such as wire, string, or thin lattice sections under a quarter-inch thick. If the support is too wide, the tendril cannot wrap around it, making a separate mesh or netting necessary.
The third attachment strategy is adhesive or clinging, relying on structures that grip rough or solid surfaces. Ivy and climbing hydrangea use aerial rootlets, which are root-like growths that extend from the stem and anchor into crevices on textured materials like bark or stone. Virginia Creeper and Boston Ivy employ adhesive pads, which are disk-like structures at the tips of their tendrils that secrete a sticky substance, allowing them to stick to any solid surface, including smooth walls.