We have a grape vine growing in our conservatory (in North Wales, UK), given to us as a cutting by a friend. (Unknown variety, sweet purple table grape.) The root is planted outside in natural soil. It has been growing happily for 10 years, and fruiting increasingly well. This year it has started putting aerial roots out of part of the stem/trunk inside where it comes into the conservatory from outside, across a slate bench. The trunk here is about 35-50mm diameter (1 1/2 - 2 inches), the aerial roots are red-pink with white tips, about 5mm across and currently about 50 - 65mm long. Are these normal, or a sign of distress? What might it lack? Should I cut them off, leave them, or even try to rig up some way of giving it water or feed via these roots?