We recently bought a house and acreage that is heavily landscaped. The property had been vacant for 3 years and the weeping willow trees suffered. We maintain the entire property with the knowledge we have, but when it come to weeping willows we are clueless. Is this type of tree delicate? I do know they require alot of water. We need to trim the branches, but when is the best time to do so? If you could help me save these 20 yr old trees I would appreciate it greatly.