Mandevillas originate from South America, usually growing as vines with trumpet-shaped, colorful flowers. They enter dormancy when exposed to temperatures below 60°F (15°C) in the winter. If you’d like to see them grow and bloom again, there are several steps you can take to help the plants wake up.
You can get a Mandevilla out of dormancy by pruning the plant, changing its soil, and placing it in a warm spot outdoors in the spring. You can also keep it indoors during the winter to make it easier to get the plant out of dormancy after the last frost.
Keep reading for a more thorough guide that expands on the basic steps above and some advanced techniques to get a Mandevilla out of dormancy.
1. Prune Your Mandevilla’s Dead Tissue
The first step to getting your Mandevilla out of dormancy is to prune off dead stems and branches. These dead parts are caused by prolonged exposure to cold temperatures and need to be removed to leave room for new growth.
The tools you will need to prune Mandevilla include:
- Sharp Shears
When To Prune Your Mandevilla Plant
The right time to prune your Mandevilla is after the risk of frost has passed. Even though you may realize that parts of the plant need to be removed, do not rush to do so in the winter.
During dormancy, Mandevillas may look dead, dropping all their leaves and not growing anymore. However, this is just a temporary state. They will soon bloom in spring if given the right care.
How To Tell Which Parts Must Be Pruned
You can recognize dead tissue in your Mandevilla by looking at the color of the stem or branch. If the tissue above the surface has gone brown, there may still be hope that the root system is functioning.
Carefully scrape the outer layer of the branch and see if it continues to look dark brown. If so, then the tissue is dead and needs to be removed. It can prevent new plant parts from growing and does not help with photosynthesis.
When pruning your Mandevilla, start with the branches that look dead and brown.
Continue trimming until the stems are about 5 to 6 inches (13 to 15 cm) above the ground.
You can trim longer branches to maintain a symmetric appearance (source). The pruning and trimming will make your Mandevilla flourish throughout spring and summer.
2. Change Your Mandevilla’s Soil and Water Abundantly
Once the frost has passed, you’ll need to repot your Mandevilla to get it out of dormancy. Early spring is the best time to do so. Repotting does not only mean changing the container but also changing the soil with a new one that’s rich in nutrients.
The best potting mixture to grow Mandevillas consists of peat moss, sand, and leaf mold in a neutral to slightly acidic PH. So make sure to repot them in appropriate soil to see them blooming in only some weeks.
After repotting it, remember to water abundantly for the first time. Then continue watering it as usual.
How Much Water Do Mandevillas Need in the Winter?
In the winter, you must periodically water Mandevilla plants every three to four weeks. During dormancy, they need much less water in winter than in the warmer seasons.
The exact amount of water your plant will need depends on the temperature, humidity, and lighting. To ensure you are not overwatering your plants, remember that the soil (at least on the surface) should remain dry.
Additionally, use containers with drainage holes. This will help remove the excess water from the soil, avoiding mold and insect infestation.
Read our guide to knowing The Signs Of Overwatering Plants.
When Should You Add Fertilizer to the Plant?
You can use fertilizer only in the spring when the temperature is unlikely to go under 60°F (15°C) again. It is the ideal time for your Mandevilla to wake up and show vital signs.
Note: Avoid adding fertilizers to your Mandevilla during fall or winter. This may force it out of dormancy and stress it out during winter. Instead, take gentle care of Mandevillas. Let it enter its natural cycle without forcing it to bloom in winter.
3. Place It in Your Garden’s Warmest Spot in Spring
Originating in South American tropical and subtropical climates (source), Mandevillas are very sensitive to Continental winter. They can leave the greenhouse or your indoor spaces only after spring has come.
Make sure you place your Mandevilla in a spot protected from the wind. However, ensure it is not sunlit all day, as the slowly waking-up Mandevillas are still fragile, and too much sunlight can cause damage to the new leaves and branches.
You can put a plastic bag around your Mandevilla to protect it from early spring’s wing or sudden temperature drops.
Should You Grow Your Mandevilla in a Container?
Instead of planting Mandevilllas in your garden, you can also grow them in containers. It’s true that growing as a vine, Mandevilla would be easier to manage in a garden bed. However, you can move your Mandevilla much more easily in a container without needing to repot it several times a year.
By doing so, you can take your Mandevilla to a greenhouse or indoors during the cold winter and then bring it back outdoors when spring comes. This may not prevent your Mandevilla from entering the dormancy stage in winter. However, it will be easier to wake it up in the spring.
Where Should You Keep Mandevillas in the Winter?
Mandevillas must be kept indoors before the first frost until after the last one. Being tropical plants, they cannot handle winter’s cold.
When bringing Mandevillas inside for winter protection, ensure their environment is kept warm like their native home in South America. A room with plenty of light is ideal so they can still get enough sunlight even indoors.
Getting a Mandevilla out of dormancy requires pruning, repotting, and providing adequate water and sunlight. Removing any dead or damaged stems and leaves will help stimulate new growth.
Make sure to water regularly but don’t overdo it to avoid root rot.