Clematis is a highly popular genus of flowering vine, prized for its vigorous growth and colorful blooms. Achieving the vertical display these plants are known for requires understanding their unique growth habit and providing the correct structural environment. This guide outlines the steps necessary to ensure your vine successfully establishes and maintains its vertical climb, transforming a sprawling ground cover into a magnificent flowering wall or screen.
Understanding the Clematis Climbing Mechanism
Clematis vines do not use suction cups, clinging roots, or long tendrils. The vine relies entirely on its leaf stalks, known as petioles, which twine and coil when they make contact with a suitable, slender object. This mechanism is highly efficient but has a distinct limitation regarding the diameter of the surface it can grip.
Petioles are relatively short and lack the tensile strength to wrap around thick objects. Generally, Clematis can only successfully coil around supports that are less than 1/2 inch to 3/4 inch in diameter. Supports much thicker than this, such as large wooden posts or mature tree trunks, are too broad for the petioles to encircle. When planted next to a thick, solid surface, the petioles cannot attach, causing the vine to flop over or sprawl across the ground. Understanding this constraint is fundamental, as the support must provide numerous thin gripping points for the petioles to utilize.
Selecting and Installing Suitable Support Structures
Selecting the appropriate support structure is paramount for success. Trellises constructed with a fine mesh or narrow lattice work are highly effective because they offer a dense network of thin attachment points. The individual slats or wires should fall within the required diameter range to facilitate easy coiling.
Wire systems, often called espaliers, provide an excellent solution for covering large, flat surfaces. These systems use horizontal rows of thin gauge wire, typically 16 to 20 gauge, stretched tautly between anchors on a wall or fence. The wires should be spaced approximately six to eight inches apart to ensure the vine has constant opportunities to attach as it grows upward.
To retrofit existing wide structures, such as a shed or pillar, attach a secondary, thin-material support. A flexible plastic or metal mesh netting with fine openings can be secured directly to the broad surface. This creates a fine-scale latticework that the petioles can easily grip.
Stability is non-negotiable, particularly for mature clematis varieties which can become heavy. Freestanding trellises must be anchored securely into the ground, often requiring concrete footings to withstand wind and the vine’s weight. Wall-mounted systems must use durable hardware that holds the support material slightly away from the wall, allowing air circulation and space for the petioles to wrap completely around the wire or mesh.
Essential Steps for Initial Training and Guidance
Initial Orientation and Tying
Once the support structure is in place, the process shifts to active management and guidance of the young vine. Immediately after planting, gently orient the flexible shoots so they point directly toward the base of the support. This initial placement is important because the petioles cannot successfully search for support if the main stem flops away from the structure.
Juvenile vines often lack the vigor to initiate twining, so manual assistance is required to establish the upward trajectory. Use soft, flexible materials, such as strips of pantyhose or fine garden twine, to temporarily secure the main stems to the support. Loop the ties loosely around the stem and attach them to the structure, leaving slack to prevent girdling as the stem thickens.
The goal is to hold the main stem close enough for emerging petioles to make contact and begin coiling. Secure the vine at intervals of every 12 to 18 inches along the stem to maintain contact with the vertical framework.
Encouraging Lateral Growth
To encourage dense, full coverage rather than a single vertical rope of foliage, guide the main stems laterally. Gently weave or spiral the initial few stems horizontally across the lower portion of the support. This technique encourages the vine to produce side shoots. These side shoots will then grow vertically, resulting in a much fuller, bushier base and better distribution of flowers.
Consistent Monitoring
Directional guidance requires consistent monitoring throughout the active growing season. New growth emerges rapidly, and shoots that miss the support quickly become entangled or droop outward. Check the vine weekly to gently tuck any wayward new growth back into the thin support mesh before its petioles harden and become less pliable. Consistent hands-on guidance during the first year ensures the clematis develops into a self-sufficient, climbing specimen.