Do you know what kind of willow they are? My experience is that weeping willow doesn't spread, or not much. Black willow on the other hand will grow on concrete if you so much as wave a stalk over the top of it. I despise black willow...it's the bane of my existence pond-wise.


Dale

[Linked Image from i90.photobucket.com]

"When tempted to fight fire with fire, remember that the Fire Department usually uses water." - anonymous