Mandevilla: Plant Care & Growing Guide

Mandevilla, also known as rocktrumpet, is a genus of flowering vines that grow in tropical and subtropical climates. The five-petal trumpet-shaped flowers are often showy and fragrant, typically coming in shades of pink, red, and white, occasionally with yellow throats. They generally bloom in summer and can stretch into fall, though in warm climates they can bloom year-round. Some species within the genus have smaller, more plentiful blooms while others have fewer, larger blooms. Their ovate leaves are usually a glossy green. These fast-growing vines should be planted in mid-to-late spring once the temperature is reliably warm and the risk of frost has passed.

Growing Mandevillas as Annuals vs. Perennials

Within their USDA growing zones, mandevilla plants can be grown as perennials; gardeners outside of their zones often like to grow these colorful vines as annuals, especially in containers.

To keep your mandevillas as tender perennials outside their hardiness zones, bring them indoors when the outdoor temperatures go down under 50 degrees Fahrenheit. When bringing your plant indoors, cut it down a bit to let it rest. Place the container in bright, indirect light and water it when the soil is dry to the touch. Mist it regularly or place it on a tray of pebbles filled with water. Return it outdoors in the spring when temperatures rise above 50 degrees Fahrenheit.

Mandevilla Care

Mandevilla plants are fairly easy to care for as long as you get their growing conditions right. The vines thrive in lots of light, warmth, and moisture, so plan to water yours whenever the soil begins to dry out and feed your plant during the growing season. 

If you wish to promote a bushier growth habit on these vines, pinch back the stems in early spring. If you let them naturally grow as vines, it’s a good idea to provide them with a trellis or other structure they can climb around. The vines also look great in hanging baskets. 

Light

Mandevilla likes the sun more than shade, but it can tolerate partial shade. These vines grow and flower best in full sun, meaning at least six hours of direct light on most days. However, they might even appreciate shelter from the hot afternoon sun at the peak of summer. A perk to growing mandevilla vines in containers is the ability to move the plant out of the harsh sun as needed so the foliage doesn’t get scorched. 

Soil

Mandevilla vines need sandy, well-draining soil with plenty of organic material mixed in. A good potting mix is a combination of peat moss, sand, and leaf mold. A slightly acidic to neutral soil pH is best, though the plant can also tolerate slightly alkaline soil.

Water

Unlike many flowering plants, the mandevilla species can withstand some dryness while continuing to flower. That said, they prefer a consistent level of moisture, so aim to keep the soil damp but not soggy. Water the plant slowly to give the soil time to soak up the moisture, and spray the leaves as well to knock off any pests and raise the humidity around the plant.

Temperature and Humidity

These plants require warm temperatures and high humidity. Temperatures should be at least 60 degrees Fahrenheit during the day and no lower than 50 degrees Fahrenheit at night for mandevilla to be planted outside. If you live in a dry climate, regularly misting your plants will help to keep humidity levels up.

Fertilizer

Fertilize your vine in spring with a slow-release, balanced fertilizer. Alternatively, you could use a liquid fertilizer at half-strength every two weeks from spring to fall. It also can be helpful to mix some compost into the soil to improve nutrition levels.

Types of Mandevilla

There are more than 100 species within the Mandevilla genus. Some of the most popular for outdoor cultivation include:

• Mandevilla sanderi: Commonly known as Brazilian jasmine, this species of mandevilla is fast-growing, reaching up to 15 feet tall. It boasts twining, woody stems and large pink-red blooms.
• Mandevilla boliviensis: Also known as white mandevilla, this species is notable for its delicate white blooms. It can grow between 3 and 10 feet tall with a 3- to 6-foot spread.
• Mandevilla laxa: Known commonly as Chilean jasmine, this mandevilla species produces masses of heavily scented white flowers, reaching up to 20 feet tall.

Pruning Mandevilla

Pruning mandevilla vines at least once a year is recommended to maintain a tidy and profusely flowering plant. Winter or early spring is the ideal time to cut back the plant before it starts to produce new growth—mandevilla flowers on new growth, so pruning too late could result in removing potential buds.

As a general rule of thumb, try not to trim more than one-third of the plant's mass at a time. You can cut back any diseased or damaged branches, as well as any branches that are creating a shape that you don't desire for the plant. To do so, first water the plant well so it's hydrated and not further stressed by your trimming. Cut any vines back to just above a set of leaves using a sharp, clean pair of pruners.

Propagating Mandevilla

The easiest way to add mandevilla to your landscape is to either buy a plant from a nursery or start one via propagation with a cutting. Here's how:

1. In the spring, take a 4- to 6-inch cutting below a leaf node (where a leaf meets the stem) from a healthy, established "mother" plant that has bloomed for at least a season.
2. Remove the leaves and buds from the lower half of the cutting.
3. Dip the cuttings in rooting hormone.
4. Plant the cutting in a pot filled with moist potting soil. Make sure to stick the cut end into the soil, and press the soil up firmly around the stem to stabilize it.
5. Place the pot in a location that gets ample filtered sunlight and boasts temperatures between 70 and 75 degrees.
6. Keep the soil moist and mist the cutting occasionally. Cuttings should take root within a month, at which point you can feed the plant and begin to care for it as normal.

Potting and Repotting Mandevilla

Caring for a potted mandevilla is easy. When first potting your mandevilla plant, choose a container that’s only slightly larger than the root ball. A container that’s too big can cause the plant to expend more energy on producing roots than growing flowers, so you might see fewer flowers until it has expanded its root system. Make sure the pot has ample drainage holes to help prevent root rot.

However, once you see roots creeping out of the container, it’s time to repot. Mandevillas are fast-growing plants, you’ll likely need to repot annually in spring. When doing so, select just one pot size up. Gently remove the root ball from the old container, set it in the new container, fill around it with fresh potting mix, and water well. 

Common Pests

Mandevilla plants generally don’t have any serious problems with diseases. However, they can attract pests, including red spider mites, scales, whiteflies, and aphids. You might notice tiny insects moving on your plants or see leaf damage and discoloration. If you have an infestation, apply insecticidal soap or horticultural oil (like neem oil) continually until all signs of infection have passed.

How to Get Mandevilla to Bloom

When it comes to getting your mandevilla plant to produce bountiful blooms each summer, there are a few must-have conditions the plant relies on. First and foremost, your mandevilla plant requires ample light in order to produce the most buds. If you don't have a single spot in your landscape that boasts six to eight hours of sunlight a day, it's a good idea to plant your mandevilla in a pot so you can move it around and "chase" the light.

Proper fertilizing is also an important factor in getting your mandevilla to bloom. Feed the plant every two to three weeks during the growing season with a fertilizer that is high in phosphorus. If you live in an especially dry climate and are watering frequently, you may want to fertilize every two weeks, as it will be washed through the soil more quickly due to water.

Common Problems With Mandevilla

This pretty and easy-care plant has a few problems, just like any other plant. Here's what to do when you spot the following issues.

Yellowing Leaves

Your mandevilla plant will let you know if it's feeling dry or otherwise ill by letting its leaves turn yellow and drop off. Too little water will make leaves yellow and curl. To repair, water the plant from the bottom, not the top, by immersing the pot in water for a few minutes so water reaches the roots.

Browning Leaves

A mandevilla with browning leaves is having the opposite problem of yellowing leaves. Brown leaves may mean the soil is too wet, the plant is in standing water, or the soil is not draining enough. Try fertilizing the plant and scheduling consistent waterings.

Brown Spots on Leaves

Brown spots and browning leaves mean two different things with mandevilla. Brown spots may indicate a case of a fungal disease called anthracnose. Overly wet leaves can lead to this disease and lead to dropping leaves, as well. Prune the affected leaves and treat the plant with a fungicide.