The Mandevilla is a popular tropical vine known for its glossy foliage and prolific, trumpet-shaped blooms that provide vibrant color throughout the warm season. Confusion often arises because the name Mandevilla is frequently used interchangeably with Dipladenia, a related plant that grows in a more compact, shrub-like form. Both plants are prized for their stunning flowers, but whether either will “come back” annually depends entirely on the winter conditions of the local climate.
When Mandevilla Returns Naturally
Mandevilla is botanically a perennial plant, meaning its natural life cycle is designed to last for more than two years. It thrives year-round in climates that mimic its native tropical environment. For the plant to return naturally without intervention, the garden must be located in an area where temperatures remain consistently warm and frost-free.
This perennial nature is only fully realized in the warmest regions, typically corresponding to USDA Hardiness Zones 9 through 11. In these locations, the vine can remain evergreen and continue to bloom for much of the year.
The plant will experience damage if temperatures drop below 50°F, and exposure to frost is generally fatal to the above-ground growth and often the root system. Because most gardeners live in zones where winter temperatures fall below this survivable threshold, the Mandevilla is typically treated as a colorful annual. The only method to ensure its return is by moving the plant indoors for the cold months.
Strategies for Bringing Mandevilla Indoors
For readers outside the perpetually warm zones, the only method to ensure the Mandevilla’s return is to overwinter the plant indoors. The timing for this transition is crucial and must occur before the first frost or when nighttime temperatures consistently fall below 50°F. The goal during this period is not to maintain active growth but to induce a state of cool-season rest, or dormancy.
Before bringing the container inside, the vine should be thoroughly inspected for any pests, such as spider mites or mealybugs, which can quickly infest indoor environments. A strong spray of water or an application of insecticidal soap can help eliminate any hitchhikers. This is also the best time to drastically prune the plant, cutting the long, vining stems back to a manageable size, often leaving only 10 to 12 inches of growth.
Once prepared, the Mandevilla should be moved to a cool, dark location, such as an unheated basement or garage, where temperatures remain steady between 50°F and 60°F. This specific temperature range is cool enough to signal to the plant that it should enter a dormant state. The plant will likely drop most of its leaves, which is a normal response to the change in temperature and light, indicating that it is conserving energy.
During this dormant period, the plant requires minimal care, which is the key to successful overwintering. Watering should be extremely sparing, providing just enough moisture about once a month to prevent the root ball from completely desiccating. Fertilizer should be withheld entirely, as the cool, dark environment slows the plant’s metabolic processes. Attempting to force growth indoors during winter will often result in weak, spindly stems and may exhaust the plant.
Waking Up the Mandevilla in Spring
Reawakening the Mandevilla begins in late winter or early spring, typically around February or March, when the days begin to lengthen. The plant must be gradually brought out of its cool, dormant state to prepare for the summer growing season. Start by moving the container to a brighter, slightly warmer location, such as a sunny window or sunroom.
The increase in light and temperature signals the plant to break dormancy and resume active growth. At this point, you can begin to increase the frequency of watering, ensuring the soil is moist but never waterlogged. Once new shoots begin to emerge, you can also start a regimen of light feeding with a balanced, water-soluble fertilizer to support the new growth.
A final, heavy pruning can be done as new growth appears to shape the vine and encourage a bushy, full plant. Since Mandevilla flowers primarily on new wood, cutting back leggy or dead stems is important for maximizing the number of blooms later in the season.
The rejuvenated plant should only be moved back outdoors after all danger of frost has passed and when nighttime temperatures are reliably above 60°F. This slow reintroduction to the outdoor environment, known as hardening off, helps prevent shock and leaf burn.