While it seems odd with so much of the US experiencing severe cold and winter weather, we have been unusually warm and sunny so far this fall/winter. Not complaining, but it seems to have confused the grape vine in the GH. The grape has shed all of its leaves from the summer, but I see new leaves coming out; not growing much yet but they are definitely opening up.
The grape vine runs up close to the glazing on the GH, and so gets plenty cold enough (usually) even in this heated GH. In past years has had no problems going dormant.
I am wondering if I should do my pruning now (which would take off most of the newly formed leaves), or wait and hope for more cold weather. Suggestions from other grape growers?
The grape doesn’t need chilling or to go into a real dormancy. If you can keep it from freezing then there is no issue with it starting to grow this early. You should prune before it starts growing too much. If you wait too long you may knock off too many new shoots that you want to keep.
It’s cool to cold that keeps a grape dormant. Yours is too warm during the day if dormancy is what you want. In my greenhouse the buds usually started to push about late Febr to early March. But I was keeping it as cool as possible during the day to get chilling on stone fruit.
Thanks @fruitnut. This GH is being used at cross purposes to some extent. I keep my potted citrus in there during the winter, and heat it to keep them above freezing. But just the sun will heat it to 90F on many winter days. Most of the plants which loose their leaves in winter can be managed (grafted apples/pears go to the barn for their cold) but the grapevine is planted in the GH soil so has to stay. Good to know that it does not need some amount of chill.
I will get on the pruning.