Overwintering Mandevillas

(Question)

I live in Etobicoke with a south-east garden exposure and have bought a Mandevilla in a pot. Will putting it in the garage (as a previous person asked) be well enough to be brought back up in the spring/summer. If so, when would one protect it in the garage and when would one bring it out in the Spring/Summer?
I have also purchased a small Dipladenia and wonder what the course of action will be with it as it is from the Mandevilla family. Many, many, many thanks!

(Answer)

It might be possible to winter the Mandevilla in your garage.  However this will depend on how cold the garage gets in winter, as the Mandevilla genus are tropical or semi-tropical plants that are unlikely to survive temperatures below 10 degrees C.  Below are are a couple links to previous questions (and answers) on the TMG site relating to overwintering Mandevilla.  In the second you will see that the enquiry related to a Mandevilla which may not have survived the winter in a garage.  You are more assured of success if you can overwinter the Mandevilla either as a houseplant or in a dormant state.  Which you chose may depend on the size of the plant in autumn.  A very long vine is probably best overwintered in the dormant state, while a low sprawling form could be a kept as a houseplant and might bloom throughout the winter.

Wintering a potted Mandevilla

Overwintering a potted mandevilla

With respect to the dipladenia, this name is given to plants that are part of the same genus as  Mandevilla, as well being the former names of a number of other tropical and semi-tropical plants.  The dipladenia requires the same kind of treatment in the winter as the Mandevilla.