Mandevilla is a showy vine with big, shiny leaves and eye-catching blooms available in shades of crimson, pink, yellow, purple, cream, and white.
This graceful, twining vine can grow up to 10 feet (3 m.) in a single season.
Mandevilla plants in winter survive the season in fine shape if you live in a tropical climate that falls within the temperature ranges of USDA plant hardiness zones 9 and above.
However, if you live in a more northern climate, planting the vine in a container is the best way to go.
This tropical plant won’t tolerate temperatures below 45 to 50 degrees F. (7-10 C.) and must be wintered indoors.
You love the display of flowers your ‘rock trumpet’ aka Mandevilla plant produces in the spring and summer. But, what is the deal on caring for Mandevilla in winter? How do you winterize these tropical plants to enjoy the flowers again next spring?
How To Get Your Mandevilla Vine Ready For Winter
As the weather becomes cooler, your Mandevilla’s flower production will slow down.
This is the right time to provide that last meal of fertilizer.
Following this, allow your plant to stay outdoors as long as possible.
- Weather permitting, toward the end of September, prune your plant back for the winter.
- You’ll want to cut it back to make it easy to bring in and easy to live with over the winter months.
- This can be a dramatic pruning, but don’t feel alarmed. Mandevilla is very tolerant of aggressive pruning.
- You can prune to within a few inches of the soil and still have incredible growth when spring arrives.
- As you prepare your plant to come winter indoors, examine it carefully for pests or signs of disease and take appropriate steps to address any problems.
- Your plant will not grow much during the winter months, if you want to enjoy it as a houseplant, don’t overdo the pruning.
- Trim it back to the size you want, and it will probably stay that way throughout the winter months.
- You may get a little flurry of leaves or stems when initially bringing the plant indoors.
- Pinch back the tips as needed.
Be advised that when pruning or pinching your plant back, you will encounter milky sap (like a Poinsettia).
This sap can irritate your skin, and it is toxic to ingest.
It’s a good idea to wear gloves while pruning and wash your hands afterward.
Overwinter Care Of The Mandevilla Vine
When keeping your plant indoors as a houseplant, provide it with bright, indirect sunlight near an east or west-facing sunny window.
Position your plant away from the door, so cold drafts will not harm it.
Kept as a houseplant, your Mandevilla vine or Dipladenia will be comfortable at normal home temperatures in the 60s and 70s. If you keep your home warmer, the plant could dry out.
In this case, maintain the plant in a cooler area of the house and/or use a humidifier to prevent excessively dry air.
Humidifier use is beneficial to people, pets, and houseplants during dry, cold winter months.
During the wintertime, the plant will grow very slowly. Remember you are just trying to maintain it.
Don’t encourage the Mandevilla to grow by feeding it. Just keep it protected and water it lightly when the soil feels dry.
Can A Mandevilla Plant Live Indoors?
The Mandevilla vine can live and grow indoors, and it could do well in a sunroom with lots of light or a very bright windowsill. However, the plant may vine as a house plant but I would not expect lots of flowers.
Dormant Overwintering
If you don’t want to bring your Mandevilla indoors during the winter, simply protect it enough to allow it to go dormant.
To do this, allow the plant to stay outdoors until it is quite cool outside, prune it back to about a foot high and move it into your basement or garage.
Take care that it stays above freezing (50° degrees Fahrenheit is best) throughout the winter, or you will lose your plant.
Some gardeners like to put the plants inside a plastic bag for the winter. Others leave them uncovered.
Either way, your plant should not be receiving sunlight. You want it to maintain a complete, resting state.
Just check occasionally to see if the soil is dry. If so, provide a small amount of water.
When it’s almost spring, bring your plants indoors and help them rejuvenate for the growing season.
Getting Mandevilla Ready For Spring
Whether you overwinter plants indoors or in an outbuilding or basement, in February, examine them for signs of illness or distress.
Provide another good pruning to remove any crowded, dead or diseased limbs.
Repot as needed and begin watering and fertilizing for growth. The plants should perk right up and begin growing again.
In late April or early May (earlier in the south), allow the plants a little time outdoors on warm, still, sunny days.
Be sure to bring them in at night and when the temperature dips.
As the weather becomes more and more reliably warm, allow the plants more time to harden and acclimate to the outdoor life.
If your Mandevilla vine has put on some new growth during the winter, this will probably die back.
Don’t be alarmed! This is normal. The plant will soon be putting out lots of healthy new growth.
When all danger of frost passes and the weather is generally comfortable, place your acclimated plants in their spring and summertime positions in the landscape.