Shrub · Apocynaceae
Mandevilla
Mandevilla × amabilis
Give it full sun and summer warmth, and mandevilla climbs and blooms in trumpets right through fall.
Full sun
Every 3–7 days
45–90°F · 7–32°C
USDA 10–11
Overview
Mandevilla is a fast-growing tropical vine from the dogbane family, prized for the big trumpet flowers it throws from summer into fall. It comes from the warm corners of the Americas and only shrugs off winter outdoors in zones 10 and 11. Everywhere colder, gardeners treat it as a summer container plant and bring it in before the cold.
What you buy at the garden center comes in two habits. The tall twining Mandevilla climbs a trellis or post and can reach well over head height, while the bushier, mounding forms sold as Dipladenia stay tidy in pots and baskets. Both want the same thing: heat, sun, and steady summer water.
It earns its keep with bloom, but it asks for full sun and a bit of care. The cut stems bleed a milky sap that stings skin and eyes, so gloves are worth keeping nearby. Give it warmth and light and it rewards you with months of color.
Care
The short version: full sun for the best bloom, steady water through the heat of summer with a drier winter rest, rich well-drained soil, and a biweekly bloom feed once it's growing.
Light
Mandevilla blooms best in full sun, ideally 6 or more hours of direct light a day. It will hold on in part shade or bright indirect light, but you trade flowers for leaves the dimmer it gets.
Water
Keep the soil evenly moist but never soggy through summer, watering every 3 to 7 days and more often in heat or in a pot. Ease off over winter and let the soil dry further between drinks while the plant rests.
Soil
Plant it in rich, well-drained ground with humus worked in, or a peat-based mix in containers. It isn't fussy about acidity and takes anything from a pH of 6.0 to 8.0, but it will rot in soil that holds water.
Temperature
It runs warm, happy between 45°F and 90°F (7°C to 32°C), and growth slows as the air cools. Anything near frost will kill it, so bring it in before nights drop below 50°F (10°C).
Humidity
Mandevilla likes high humidity and the moist warmth of its tropical home. Indoors over winter, group it with other plants or set the pot over a pebble tray to keep the air around it from drying out.
Feeding
Feed every two weeks through spring and summer while it's actively growing. Reach for a high-phosphorus bloom fertilizer such as 10-20-10, since too much nitrogen builds leaf at the expense of flower.
Pruning
Prune in late winter or early spring before new growth, cutting out old crowded stems and shortening the rest, and pinch young plants to bush them out. Wear gloves, because the cut stems weep an irritating milky sap.
Repotting
Move it up a pot size every 1 to 2 years, or when roots circle the pot, water runs straight through, or growth and bloom stall. A pot that drains freely matters more than a big one.
Size & spacing
Mandevilla ranges from a tidy 3 feet to a towering 3 to 10 feet (0.9 to 3 m) depending on the type, and spreads 3 to 4 feet (91 to 122 cm) wide. Give a climbing form a trellis or post to run up.
When to plant
Mandevilla runs on warmth and won't take frost. Start seed or settle overwintered plants indoors in late winter, move them outside once nights hold above 50°F (10°C), and the flowers come on from summer through fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: late winter to early spring
- Plant: after last frost when nights stay above 50 degrees F
- Harvest: summer through fall
Hardiness
USDA hardiness zones: 10–11
Temperature: down to -1°C
Troubleshooting
Most mandevilla trouble shows up either as pests on overwintering plants or as a vine that grows leaves instead of flowers. Catch the early signs and you can turn it around before it spreads. Match what you see below, then act while it still helps.
Wilting leaves and soft, blackened roots in soggy soil
When the soil never dries and the leaves wilt anyway, suspect root rot from overwatering. Slide the plant out and check the roots, since healthy ones are firm and pale while rotted ones turn dark, soft, and foul. Stop watering, repot into fresh fast-draining mix, trim the dead roots, and make sure the pot drains freely from now on.
Fix:
- Stop watering and let the soil dry out
- Repot into fresh, fast-draining mix and trim away rotted roots
- Ensure the container has drainage holes and discard standing water
Fine webbing and stippled, yellowing leaves
Those tiny moving dots and the silvery stippling point to spider mites, which thrive in the warm, dry air around overwintering indoor plants. Tap a leaf over white paper to confirm the specks, then rinse the foliage hard, especially the undersides. Treat with insecticidal soap or horticultural oil, raise the humidity, and keep the plant apart from others until it clears.
Fix:
- Rinse foliage with a strong spray of water, especially leaf undersides
- Treat with insecticidal soap or horticultural oil, repeating per label
- Raise humidity and isolate the plant to limit spread
Cottony masses and sticky residue on stems and leaf joints
Sticky honeydew and white fluff are the calling cards of mealybugs, scale, aphids, or whitefly, all of which love an overwintering vine. Check the stem junctions and leaf undersides to see which one you have. Dab mealybugs and scale with an alcohol-soaked swab, spray the rest with insecticidal soap or horticultural oil, and cut away any growth that's badly overrun.
Fix:
- Wipe off mealybugs and scale with a cotton swab dipped in rubbing alcohol
- Spray with insecticidal soap or horticultural oil, repeating as needed
- Remove heavily infested growth and isolate the plant
A lush green vine with few or no flowers
A mandevilla that grows plenty of leaf but skips the flowers is almost always short on sun, since it needs full sun to bloom well. Cool nights and a heavy hand with nitrogen both push leaves over flowers too. Move it into at least 6 hours of direct sun, keep it warm, and switch to a high-phosphorus bloom feed like 10-20-10.
Fix:
- Move the plant to a full-sun location
- Switch to a high-phosphorus bloom fertilizer such as 10-20-10
- Keep it warm, as bloom slows in cool conditions
Toxicity
Mandevilla belongs to the dogbane family and bleeds a milky sap that no one and nothing should eat. Chewing the foliage gives pets a mild upset stomach, and the sap stings skin, eyes, and mouths. None of the plant is edible, so keep it away from grazing animals, pets, and small children, and wear gloves when you cut it.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
A cat that nibbles the leaves usually gets a mild upset stomach with drooling and maybe some vomiting. The milky sap can also leave the mouth sore and irritated.
Dogs Mild
Chewing the foliage tends to bring on drooling and a bit of vomiting in dogs. Contact with the cut sap may redden the muzzle or irritate the mouth.
Horses Mild
The same irritant sap can upset a grazing horse, with drooling and mild stomach trouble the likely result. Most leave the bitter foliage alone once they taste it.
Rabbits Mild
A rabbit that samples the leaves may drool and go off its feed for a while. Keep clippings out of the hutch and offer safer greens instead.
Livestock Caution
Grazing animals rarely choose this bitter, sappy plant, but a hungry one could get an irritated mouth and a queasy gut. Fence it off where stock roam.
Birds Caution
There's little record of harm to birds, yet the irritant latex makes it worth keeping out of reach. Treat curious pet birds with caution around the foliage.
People Caution
No part of the plant is meant to be eaten, and swallowing the foliage can irritate the mouth and stomach. The milky sap is the bigger nuisance, since it stings skin and eyes, so wear gloves and wash up after pruning.
Wear gloves when pruning or handling cut stems because the milky latex sap can irritate skin and eyes; wash hands after contact and keep cuttings away from pets and children.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Mandevilla comes in a stack of named hybrids and series, but a few turn up again and again. These are the ones worth knowing by name.
Alice du Pont
A classic large vining type whose deep pink trumpet flowers carry it to around 20 feet outdoors.
Sun Parasol series
A popular run of free-flowering hybrids in many colors, from compact mounds to vigorous climbers.
Red Riding Hood
A vigorous vine that blooms in deep rose-red.
Dipladenia (Mandevilla sanderi forms)
The bushier, mounding trade forms with smaller glossy leaves, still sold as Dipladenia but now grouped under Mandevilla.
How to propagate
Mandevilla is easiest to multiply from cuttings, though patient growers can also raise it from seed.
Stem cuttingsModerate
Spring through summer · 4-8 weeks
Cuttings are the reliable way to copy a mandevilla. In the warm season, take softwood tips of new growth, strip the lower leaves, and root them in a well-drained mix, where a dip of rooting hormone lifts your odds and roots take hold in 4 to 8 weeks. Wear gloves, since the cut stems ooze the same irritating milky sap.
SeedModerate
Late winter to early spring · Several weeks to germinate
You can raise mandevilla from seed sown in late winter to early spring, though it takes several weeks just to germinate. Most gardeners skip it, because cuttings root faster and keep the named cultivar true to type.
Myths
Dipladenia is a completely different plant from Mandevilla.
Dipladenia is just the old genus name, and these plants all sit in Mandevilla now. The trade keeps the two words apart to flag a difference in habit, not in genus: the tall twining types are sold as Mandevilla and the bushy, mounding Mandevilla sanderi forms as Dipladenia.