Hi - wonder if anyone has attempted to create a living willow 'tunnel' / shelter for horses? I have planted 2 rows of willow (only last year so early days) - planted the row approx. 12 - 15 feet apart. The idea is to have a tunnel / shelter for the horses to use - size approx. 15 feet high x 12-15 feet wide. Is such a thing possible? The willow is currently about 6-7 feet high and a bit spindly. Any help / advice would be appreciated. Thanks