Over-wintering mandevilla vines indoors

(Question)

After the leaf drop occurs should the vines be cut back , if yes how much? Thank You

(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. They are not hardy to Toronto winters.  There are two options for overwintering the vine inside when the weather starts to cool.  Before you bring it in you can prune the plant to approximately half its size.  Place it on a bright window and water it when it starts to get dry. Alternatively you can allow the vine to go dormant.  This involves pruning it back to twelve inches and keeping it in a cool dark place where the temperature will be consistently kept at ten degrees Celsius.  A garage or cool basement might be appropriate.  With this option the plant needs to be watered infrequently to keep it from completely drying out.