How to Care for Mandevilla? | Keep This Tropical Bloomer Thriving

Mandevilla care requires full sun, warm temperatures, well-drained soil, and careful watering, with protection from frost since the plant is not cold-hardy.

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Mandevilla is a fast-growing tropical vine that delivers trumpet-shaped blooms all summer. It is a showstopper on a trellis, a porch railing, or a patio pot. The catch is that it has no tolerance for cold, wet feet, or neglect of support. Follow the five care pillars below, and you will get months of flowers with surprisingly little fuss.

Light, Water, and Soil Basics

Get these three dialed in, and the rest of mandevilla care is maintenance. Give the plant at least six hours of sun each day for the heaviest bloom, though four to six hours can still produce flowers. Clemson University recommends full sun or partial shade outdoors and bright indirect light indoors, ideally behind a curtain-filtered window. More sun equals more flowers.

Water thoroughly and then let the top inch of soil dry before watering again. Never let the pot sit in standing water. Root rot is the fastest way to kill a mandevilla, and it usually comes from watering on a calendar schedule instead of checking the soil. In winter dormancy, reduce watering substantially. Clemson recommends a soil blend of equal parts peat moss, potting mix, and builder’s sand for containers. A standard fast-draining potting mix with added perlite or bark also works well.

Temperature, Humidity, and Feeding

Mandevilla is tropical and needs warmth. The Royal Horticultural Society (RHS) advises day temperatures around 70°F and night temperatures around 65°F from spring through autumn. HGTV notes that plants are happiest where nighttime temperatures stay above 40°F, and potted plants should come indoors well before frost. Indoors over winter, a spot around 55 to 60°F is fine while the plant rests.

Feed every two weeks during spring and summer with a phosphorus-forward fertilizer such as a 10-20-10 blend, per Clemson’s guidance. Stop fertilizing in winter when the plant goes semi-dormant and needs only minimal water and no food.

Pruning, Training, and Overwintering

Mandevilla climbs, so it needs a trellis, stake, or frame from day one. Without support, the vines turn into a tangled, leggy mess. Pinch young plants to encourage branching. Prune hard in late winter or early spring before new growth starts, and never remove more than one-third of the plant at once, according to HGTV.

In colder climates, bring the plant indoors before nighttime temperatures fall below about 50°F. Place it in a bright, cool spot and cut back watering. Many growers keep mandevilla in a cool, dim room around 55 to 60°F through winter, letting it go nearly dry between waterings.

Three Common Mistakes (and How to Avoid Them)

Overwatering. This is the number one killer. Mandevilla likes consistent moisture, but it cannot sit in wet soil. Always check the top inch of soil before watering, and make sure the pot drains freely.

Too little light. A mandevilla in shade grows leaves but few flowers. Move it to a sunnier spot or supplement with a grow light indoors.

Skipping support. Without a trellis or stake, the vines tangle and fail to bloom well. Install support at planting time, not after the plant is overgrown.