We just purchased two mandevilla vines. In researching how to tend to them, I read that they need a trellis to grow on (of course), but that to keep them alive in the winter they should be taken indoors. Obviously, the whole trellis could not go indoors. Should they be cut off the trellis at some point? If so, when and how much?
How to Grow Mandevilla Vines
Certified GKH Gardening Expert
They are usually grown indoors unless you live in a warm climate. If you are leaving it outside for summer and bringing the plant idoors for over wintering, you can cut the plant back by a third. This article should help you with its care: https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm