is it good for putting green and fringe? HOW MANY LBS PER SQUARE FOOT IF MY GREEN IS 15X18 TOTAL WITH FRINGE IS 17X2O?

Yes, Silica Sand can be used for putting green and fringe, however, the product Putting Green Infill is specifically made for putting greens turfs and is a good choice as well. You may use the calculator on the product page to calculate the number of bags of infill you would need. Each bag of Silica Sand covers approx. 33 sq ft.