Question
Hello Jim, can you tell what the min. Distance a weeping willow should be
planted, in relation to a pool. Mine is 42 ft. from the edge of the pool. Will
there be a problem with the roots? Thank you for your advice!  

Answer
A weeping willow at maturity has a spread of about 35 feet which means the roots could reach 15-20 feet from the trunk. The roots on the outside will be fibrous and small.  The roots spread about 1 1/2 time the width of the branches. So a willow 42 feet from the poll should not be a problem. The roots tend to seek water and IF there is a leak then they will tend to grow that way. I do not think you will have a problem with the willow and the pool.