Mandevilla is a popular tropical vine known for its vibrant, trumpet-shaped flowers. Native to the warm, humid regions of Central and South America, these ornamental plants are vigorous climbers. They add a striking visual element to gardens, whether in containers or hanging baskets, and are cherished for their continuous blooming throughout warmer months.
Mandevilla Care Essentials
Mandevilla plants perform best with ample sunlight, ideally at least six hours daily. While they tolerate some partial shade, especially in very hot climates, abundant light is necessary for profuse flowering. An east-facing spot with morning sun or a south-facing location with protection from intense afternoon rays can be beneficial.
Consistent moisture is important for Mandevilla, but avoid waterlogging, which can lead to root rot. Allow the top one to two inches of soil to dry out slightly between waterings. During hot, dry periods, daily watering might be needed, while in cooler weather or dormancy, reduce frequency.
Well-draining potting mix is suitable for Mandevillas grown in containers. A good mix contains ingredients like peat moss, pine bark, and perlite or vermiculite to ensure proper drainage and aeration. For plants grown directly in the ground, amending heavy clay soils with organic matter improves drainage. Mandevillas prefer soil that is slightly acidic to neutral, with a pH range between 6.0 and 7.0.
During their active growing and blooming seasons, from spring through fall, Mandevilla plants benefit from regular feeding. Apply a balanced liquid fertilizer, such as a 10-10-10 formulation, or one higher in phosphorus, like a 10-20-10, every two to four weeks. A higher phosphorus content encourages more abundant flower production. Fertilization should be reduced or stopped completely during the dormant winter months.
Mandevilla thrives in warm temperatures, ideally maintaining daytime temperatures between 65°F and 80°F (18°C and 27°C) and nighttime temperatures no lower than 60°F (15°C). These plants are not tolerant of frost and will be damaged or die if exposed to temperatures below 50°F (10°C). High humidity levels are also advantageous for Mandevilla.
Pruning and Training Mandevilla
Pruning Mandevilla plants maintains shape, controls size, and encourages bushier growth with more abundant flowering. Light pruning, including deadheading spent flowers, can be performed throughout the growing season to manage unruly stems. More substantial pruning should be carried out in late winter or early spring, just before new growth emerges.
To promote a fuller, bushier plant, pinch back the tips of young stems. When pruning to manage size or shape, make cuts just above a leaf node or branching point. Remove any dead, damaged, or diseased stems completely to maintain plant health.
Mandevilla plants are natural climbers and benefit from support structures. Provide a trellis, arbor, or stakes for their vines to twine upwards. Gently guide new growth onto these supports, using loose ties if necessary, and the vines will naturally wrap around the structure.
Overwintering Mandevilla
Mandevilla plants are tropical perennials and cannot withstand freezing temperatures, making overwintering necessary in cold winter regions. Before the first frost, prepare the plant for indoor conditions. This involves inspecting for pests and pruning it back by one-third to one-half of its size for easier indoor placement.
During the indoor overwintering period, Mandevillas prefer a cooler environment, ideally with temperatures ranging between 50°F and 60°F (10°C and 15°C). They should be placed in a location that receives bright, indirect light. Watering frequency needs to be significantly reduced; water only when the top few inches of soil feel dry to the touch. Fertilization should be avoided entirely during this dormant phase.
Once outdoor temperatures consistently remain above 50°F (10°C) and the risk of frost has passed, typically in late spring, Mandevillas can be gradually moved back outdoors. It is important to acclimate them slowly to brighter light conditions over a period of one to two weeks. This gradual transition helps prevent leaf scorch from sudden exposure to intense sunlight.
Common Mandevilla Problems
Insufficient light exposure is a common reason for Mandevilla not blooming profusely. Incorrect fertilization, particularly too much nitrogen, can also inhibit blooming by promoting leafy growth over flower development. Both overwatering and underwatering can stress the plant, leading to reduced flowering.
Yellowing leaves on Mandevilla often indicate watering issues, such as overwatering causing root rot, or inadequate drainage. Nutrient deficiencies, particularly a lack of iron or magnesium, can also cause yellowing foliage. Pests like spider mites or mealybugs, which feed on plant sap, may also contribute to discolored leaves.
Mandevilla can be affected by common garden pests, including spider mites, mealybugs, aphids, and whiteflies. Regular inspection is recommended; use horticultural oil or insecticidal soap for control. Fungal diseases, such as powdery mildew or leaf spot, may develop with high humidity or poor air circulation. Ensure good air flow and avoid overhead watering to prevent these issues.