Mandevilla is a summer favorite for its showy flowers and tropical flair. But unless you live in a warm climate, this stunning vine won’t last until next year. By overwintering mandevilla you can keep this gorgeous garden plant for years of enjoyment.
Perennial mandevilla plants will only survive winter if you live in a tropical climate in USDA hardiness zones 9 or above. It can’t tolerate temperatures below 45 to 50°F (7-10°C). So if you live in a cold climate, overwintering is a must.
There are a couple different ways you can care for a mandevilla over winter so you can grow it again next summer. I’ll walk you through when and how to overwinter a mandevilla so you can enjoy its beautiful blooms and dramatic vining foliage for years to come.
Benefits of Overwintering Mandevilla
Though many gardeners grow mandevilla as an annual, buying new plants each spring can be costly. These tropical plants are unable to tolerate cold, so if you live in a cold winter climate you will have to buy a new plant every year.
That’s where overwintering comes in. Bringing mandevillas indoors can help you cut costs because you can keep growing the same plant year after year.
How to Overwinter a Mandevilla
Wintering mandevilla plants indoors isn't difficult, provided you meet a few of their basic needs. First and foremost, timing is key. Bring mandevillas indoors for winterization before the first frost. Even brief exposure to cold is likely to lead to the loss of your plants. The best time to bring plants indoors is as soon as temperatures are consistently below 60°F (15°C).
Once your mandevilla plants are inside, you can begin the overwintering process. There are two ways you can overwinter mandevilla plants: as houseplants or in a dormant state. I’ll walk you through how to do both methods.
As a Houseplant
The first method of overwintering is growing a mandevilla indoors as a houseplant. To start, prune your mandevilla to a manageable size so it fits inside your home. These graceful, twining vines can grow up to 10 feet (3 m) in a single season, which is too large for most homes.
After pruning, put your mandevilla in a spot where it will get plenty of bright sunlight. Position the container near a sunny window, where it will receive bright, indirect light throughout the day. If your home is lacking in natural sunlight, an LED grow light, like this one from Amazon, can provide the correct amount of light a mandevilla needs.
Normal indoor room temperatures are fine for overwintering. Mandevillas do best with temperatures between 60-70°F (15-21°C). Keep plants away from drafts by positioning them away from heating and cooling vents.
Water your mandevilla every week and trim as needed to maintain the desired size and shape. Don't expect flowers, though, because mandevillas don't bloom during winter.
As a Dormant Plant
Many gardeners overwintering a mandevilla plant for the first time choose to do so by putting plants into a state of dormancy. This technique requires little care and allows you to overwinter more plants in a smaller space and with greater ease.
Put your plant in the sink and drench the soil and tubers thoroughly to wash out any common mandevilla pests that may be lurking in the potting mix. Then cut the entire plant back to about 10 inches (25 cm) with a pair of sharp, clean pruners. Garden pros, including Editor-in-Chief Melanie Griffiths, swear by these pruning shears from Felco on Amazon.
Next, place the plant in a dark room with temperatures between 55 and 60°F (12-15°C). Temperatures should not be allowed to dip below freezing, as that may harm plants. A heated garage is an ideal location. Water sparingly throughout the winter, providing only enough moisture to keep the potting mix from becoming bone dry.
In late winter and early spring, look for signs of new growth. This means plants are breaking dormancy. When that happens, move them to a warm, sunny room and resume watering and fertilizing mandevillas as normal.
What to Do in Spring
Mandevillas kept as houseplants are likely to resume active growth as the days lengthen in spring. You can begin to harden off plants at that time. That means gradually introducing plants to outdoor conditions over the course of several weeks.
If you put your mandevilla plants into dormancy, you can begin reawakening in late winter. Position plants in a sunny location. Active growth should resume over the course of several weeks. After plants begin greening up and showing signs of new growth and all chance of frost has passed, harden off mandevillas outdoors.
Either way you decide to winter your mandevilla, don't move it back outdoors until temperatures are consistently above 60°F (15°C). This is also a good time to repot mandevilla plants with fresh potting mix, like my favorite Miracle-Gro blend for potted plants, which you can find on Amazon.
Frequently Asked Questions
Can mandevilla be kept as a houseplant?
Mandevilla plants make good houseplants through winter. Provided they receive consistent warmth and light, most species can be kept with ease until spring. At that point, move their pots outdoors and resume growing as usual.
Does a vining mandevilla come back every year?
Mandevilla plants are perennials that are hardy to USDA growing zones 9-11. While most vines are evergreen in nature, those grown in cooler climates may remain dormant through winter. But those growing plants outside its hardiness range will find mandevilla behave as annuals and will require intervention in order for plants to return.
