Knowledgebase
Mandevilla (overwintered) #899142
Asked April 28, 2025, 11:36 PM EDT
I have three pots of Mandevilla‘s, the two outside ones in the photo are three years old. The middle one is on its second year. Last year, only the middle one tried vining. Now they all have very spindly vines after keeping them in a sunny south window. Question one, ido I cut the vines back any, or will that just make them bush out. question two, since they are on top of my water barrel is OK to leave them hang down, or put a short little tepee of rods for them to climb. Thinking about putting the middle one on the ground in front of a trellis, where I need to hide some electrical stuff on the outside of the house. The picture of them blooming with the sweet alyssum is from last year. I was very happy with it.
thanks,
Becky Prigge
Henry County Ohio
Expert Response
Mandevilla is commonly grown as a houseplant, patio plant or bedding
annual in temperate regions. They grow best at 65 to 70 degrees
F. If grown outdoors, plant in a container as they are cold
sensitive; bring indoors in areas with frost and allow soil to dry
out during the winter.
The spindly vines are likely the result of keeping the plant in a sunny south window and a lack of pruning. They need bright, but indirect light when
indoors. They also need an average room temperature and high humidity.
Soil should remain moist but not soggy. Prune before placing back
outdoors in the spring. If you cut the vines back, yes, they will
bush out a bit, but if you selectively prune those vines that are the
longest and look the worst, they will still vine. Mandevilla prefers moist, well-drained soil outdoors and appreciates afternoon shade in hot, humid climates. Provide it with plenty of water in the summer. Pinch long stems back for a bushier habit. It may need a trellis or stake to remain upright.
You can let the vines hang from the top of your water barrel. If you prefer a
more upright plant, then a small trellis can keep them upright.
The plant you plan to put in the ground will be happy to climb a trellis as long as the plant gets some afternoon shade and the electrical box doesn’t
throw too much heat on the plant.
Clemson University has a wonderful handout about Mandevilla that you can access here:
https://hgic.clemson.edu/factsheet/mandevilla/
It will also advise about soil and water needs and any insect problems, though Mandevilla is hardy.
By the way, the picture with the sweet alyssum is lovely. As is your cat.
I hope this helps.
