I have a Mandevilla in a pot which got quite tall and is still blooming on a trellis. I have heard you say that they need to be cut to release them from trellis before moving them indoors. Does that mean I should do the same or cut back more because it is in a pot? I will be storing it in the garage for the winter. Does it need light and water throughout the winter?
Typically mandevilla vines are quite prolific during the growing season. Many plants, even those grown in containers, are usually entwined in a fence or trellis of some sort, so cutting is necessary to release them to make the move indoors. Cut as little as possible when you move them, since there will be some natural decline in the garage. Unless your garage is warm, they need very little care for the winter months. The goal is to keep them from freezing, not keep them actively growing. They won’t look perky when you move them back outdoors next spring, but prune them hard then, repot, water and fertilizer and they should rebound.