I brought the plant indoors,it sits in a south facing window, gets plenty of sunlight. I'm getting new growth along with leaves dropping. Should I trim it back or trim the branches with dead leaves. i live southern Delaware are winters can be very cold.
Wintering Mandevilla Hybrid
Mandevilla goes dormant over the winter which is probably why it is dropping leaves. Ideally, it should be in 60-65 F room and watered sparingly. Come spring and brighter light (winter light does not simulate summer light), new growth will appear. It is then time to restart regular fertilization and regular watering.