In a pot? In a green house? In the ground outside a greenhouse, but growing inside? In its own ground. in reasonably good soil, facing south or south west? All I can suggest is when you get to mid November....take off all the side shoots and leave it completely shorn. As it stirs into growth in the spring try Growmore and watering if it has been dry. Our vine is about 24 years old....Pinot Noire. Planted in the garden. It has never been fussed over. Its gets to over 40 feet long. Curtailed this year. Maybe needs a bit more time to get down a really good root system than 3 years. Ours has a trunk about 6-8 inches now