The Mandevilla, often sold as Dipladenia, is a tropical genus admired for its vibrant, trumpet-shaped flowers and rapid growth habit. As a popular ornamental plant, it naturally seeks to climb, adding vertical interest to gardens and patios. However, this vine does not possess the aerial roots or adhesive pads needed to cling to surfaces independently. The Mandevilla is a twining vine, meaning it requires training to successfully ascend a support structure.
Selecting the Ideal Climbing Structure
Choosing the correct support is the first step in successful Mandevilla training, and the structure must be ready before the vine begins its vigorous growth spurt. Mandevilla vines thrive on supports with a relatively small diameter, ideally less than one inch thick, as this allows the new tendrils to easily wrap around the material. Trellises constructed from thin wire, mesh, or narrow wooden lattice strips are typically more effective than thick wooden posts or overly robust structures that the vine cannot fully encircle.
Metal trellises offer durability, but they can absorb and retain significant heat when placed in direct sun, potentially scorching sensitive new growth where the stem makes contact. Wooden lattice provides a more rustic aesthetic and remains cooler, though it may degrade faster when exposed to constant moisture. Regardless of the material, the structure must be placed firmly in the container or ground immediately adjacent to the Mandevilla’s base, minimizing the distance the new shoots must travel to find support.
Mandevilla plants can reach heights between 10 and 20 feet under optimal conditions, so the chosen support should be tall enough to accommodate at least the first season’s growth, generally 5 to 6 feet. Structures shaped like a fan or a simple vertical rectangle are common, offering ample surface area for the vines to spread as they ascend. Obelisk-style supports are also highly suitable, as they encourage the vines to spiral upward, creating a dense, columnar display of foliage and flowers.
The structure’s placement should be stable, especially when the plant is potted, because the weight of the mature vine and its flowers can make the entire system top-heavy. Ensuring the support is secure from the outset prevents the need for disruptive repositioning later, which could damage the delicate twining stems or root system. A thoughtful selection maximizes the plant’s natural climbing propensity and simplifies the subsequent training process.
Step-by-Step Guide to Training the Vines
The process of training the Mandevilla vine involves identifying new growth and manually guiding it onto the prepared support. The most effective time to begin training is when the new shoots, or tendrils, are still flexible and only a few inches long. These actively growing tips are searching for a surface to wrap around.
To secure the vine, gather soft materials such as padded plant ties or garden twine, which will not cut into the stem as it expands. Identify the longest, most vigorous new tendrils that are straying from the support structure. Gently bend these tendrils back toward the trellis, taking care not to snap the delicate growing tip.
Mandevilla vines exhibit a strong circumnutation pattern, meaning they naturally grow in a spiraling motion, typically winding in a clockwise direction. Loosely wrapping the vine around the support in the same direction mimics this natural tendency. It is not necessary to tie every point of contact; instead, secure the vine at strategic points, such as where a long section meets the trellis or at the base of a leaf node.
When tying the vine, ensure the loop remains loose enough to accommodate several months of stem thickening without causing constriction. A tight tie will girdle the stem, restricting nutrient and water flow, potentially killing that section of the vine. The goal is to provide initial adhesion, allowing the vine’s natural twining action to take over as it elongates.
If a vine has been neglected and grown long and tangled on the ground, it must be carefully untangled before being directed upward. Start at the growing tip and slowly unwind the stem from any obstacles or other vines, then guide the entire length onto the trellis. This prevents the plant from expending energy on ground-level growth and redirects it toward the vertical support.
Ongoing Care and Encouraging Vertical Growth
Once the Mandevilla is established on its support, ongoing maintenance is necessary to keep it tidy and promote continuous upward growth. Routine inspection should involve checking all ties to ensure they are not becoming too tight and scanning for any new tendrils that are wandering away from the trellis. Promptly redirecting these stray growths ensures the overall shape remains dense and vertical.
Pruning plays a role in managing the plant’s energy and direction. Pinching or “tip pruning” the terminal bud on side shoots encourages the plant to branch out, creating a bushier appearance at the base and redirecting energy into fewer, stronger main stems. This method helps prevent a sparse bottom with all the growth focused at the top.
If a vine grows beyond the height of the support structure, it will begin to hang down or become tangled. Cutting the vine back to a strong node just below the top of the trellis will stimulate new lateral growth. This growth can then be trained horizontally along the top of the structure or redirected back down. This keeps the plant contained and maximizes the use of the support.
Vigorous vertical growth is supported by adequate energy production, meaning the Mandevilla requires plenty of sunlight and appropriate nutrition. Placement in a location receiving six or more hours of bright, indirect sun is optimal, alongside regular feeding with a balanced fertilizer. This combination of structural support and manual training ensures the Mandevilla maintains its vertical ascent and provides a continuous display of flowers.