Mandevilla

(Question)

We brought our mandevilla in for the winter.
It had few flowers over the winter indoors, and it has lots of green leaves now ,but very few flowers. We are now ready to take it on our terrace and was wondering how we can make it flower profusely like it did last summer? I did fertilize it every 2 weeks during the winter( 15-30-15) Sould we cut it right back ? It is the pink variety.
Thank you very much.

(Answer)

Thank you for contacting Toronto Master Gardeners.  Mandevilla vines are native to Brazil. They grow to about eight to ten feet tall and have trumpet shaped flowers. There are two options when overwintering mandevillas:

Mandevillas can be overwintered in a dormant state, i.e., cut back to approximately half its height and keep it in a cool, dark space such as a basement or garage, or they can be treated as a houseplant if your conditions are appropriate. Mandevillas need to have bright, indirect sunlight to thrive.

Starting in February, it is recommended the plant be pruned back well and fertilized once a month. During spring and summer, while it is actively growing (i.e., beginning when you see a flush of new growth),  fertilize with a liquid high-phosphorus product, e.g., 10-20-10 every 2 weeks. Repot the vine and put it outside once all danger of frost has passed. Last frost date for Toronto is May 11. Be sure to harden off the plant to get it use to the high uv of the sun, so introduce it gradually to the outdoors. Wear gloves when pruning as many members of this plant family have a milky sap that can be irritating.

We have several Q&A concerning mandevilla care posted on our website.    It’s easy to find previous Q&A on the website – just go to the Toronto Master Gardeners home page and enter the search term (e.g., “mandevilla”) in the search box under “Find it here”, on the right of the page.

Clemson Cooperative Extension’s Mandevilla  provides further detailed information about how to grow the plant.

May 2, 2022