I have a new black grapevine (name not known) growing in a large pot inside an unheated greenhouse. I made sure that the variety did not require greenhouse heating, but it appears to be loosing some of its leaves and some are turning yellow. I've checked for diseases and it appears clear. Is it normal for grapevines to drop their leaves in winter?
Certified GKH Gardening Expert
Yes, it is normal for grapes to lose their leaves in the winter. It is entering dormancy and will come back in the spring.