I planted a virginia creeper earlier this year in a wooden trough at the side of my house. After a shaky start it went from strength to strength and grew to about 8-10 ft high under and over trellising fixed to the wall. Suddenly, over the past couple of weeks all the leaves have fallen off. They were such a beautiful red russet colour and so many of them. Now there are only three or four at high level left. Can anyone advise me of what could be wrong and if it can be saved. It is so sad to see it like this.