Hi. I wasn't sure which was the best forum for this question. I have what I understand to be a European Walnut Tree that is seven years old. It has had a bit of trauma in its second or third year in that a lot of its new growth was broken off. Last year it had a good crop of healthy leaves; but what was unusual was that the tree did not produce leaves until the end of August and it kept them until mid November. Most other trees had lost their leaves by then. I live in Ireland. So, last year it produced leaves much later that all the other trees and held onto those leaves for between 2 and 3 months. This year however, it has not produced any leaves, even though the tree appears be alive. When I scratch the bark, it appears to be vibrant and healthy. Directly under the bark it is bright green and sappy. I am hoping to do something to trick this tree back into action. I am prepared to dig it up an relocate it to a glasshouse or to build a temporary polytunnel around it. Is there anything I can do? What are the stimuli that trigger the tree to produce leaves? Any mad scientists out there who can help? Thanks a lot.