The willow collection (Salix sp.) has 7 species, 10 cultivars and a total of 47 specimens. Willows are shallow rooted trees and shrubs and the best known landscape plants are weeping willow trees (generally Salix alba ‘Tristis') and the pussy willow shrub (generally Salix discolor). Willows are most useful in the landscape near water bodies and streams where they have plenty of freedom to grow and their graceful forms displayed. Their roots can clog drain pipes in a matter of months if planted around the house!