Mandevilla is a genus of tropical and subtropical flowering vines, native primarily to Central and South America, cultivated for their vibrant, trumpet-shaped blooms. These plants are often grown in containers on patios and decks, bringing a tropical aesthetic to any space. They are frequently misidentified as the similar-looking Dipladenia, which has a bushier, more compact growth habit. Mandevilla vines are natural, vigorous climbers that require a structure to support their upward growth.
How Mandevilla Vines Climb
Mandevilla utilizes a specific botanical mechanism to climb, categorized as a twining vine. This means the plant does not use specialized structures like adhesive aerial roots or grasping tendrils to attach to surfaces. Instead, the young, flexible stem actively spirals around a suitable support.
The stem’s growing tip searches for a narrow object and wraps itself, or “twines,” around it in a steady, helical motion. This spiraling action provides the stability the plant needs to ascend toward sunlight. This method contrasts with vines like ivy, which use sticky rootlets, or grapevines, which use coiling tendrils. The dependence on a narrow support means Mandevilla’s climbing success relies heavily on the infrastructure chosen by the gardener.
Providing the Right Vertical Support
Because of the Mandevilla’s twining habit, the support structure must meet specific physical requirements. The vine’s stem needs a relatively narrow diameter to successfully wrap around and gain purchase. If the support is too thick, the vine cannot fully encircle it and will fail to climb effectively.
For vigorous climbing varieties, which can grow between 3 and 10 feet in a single season, the individual components of a trellis or arbor should have a diameter of less than one inch. Supports that are too wide, such as a thick wooden post or a large wall surface, will not allow the stem to spiral. Suitable structures include obelisks, wire mesh, thin metal rods, or wooden trellises with slender slats.
The chosen support must also be sturdy enough to bear the weight of the mature vine, which can become heavy over time. Appropriate materials include weather-resistant cedar, metal, or durable twine. Installing the vertical structure at the time of planting ensures the young vine has immediate access to a pathway for growth.
Managing Growth and Training
While Mandevilla is a natural climber, it benefits from initial guidance to ensure it uses the support structure efficiently. When first planted, the young, pliable stems may need to be manually secured to the trellis using soft fabric ties or biodegradable twine. These ties provide a temporary anchor until the vine begins its natural twining action.
As the vine grows, the gardener should regularly weave the leading tips of the stems through the support structure to encourage upward growth and prevent sprawling. Pruning manages both size and shape, particularly for container plants. Cutting back the stems, especially in late winter or early spring, helps control size and stimulates side shoots, resulting in a fuller, bushier plant with more flowering potential.
The growth rate of Mandevilla is moderate to fast, meaning continuous intervention is necessary throughout the growing season. If a stem begins growing in an undesirable direction, it can be gently unwound and redirected to a more suitable section of the support. This active management ensures the plant remains tidy and maximizes the display of blooms.