Last year the trees that grow on city streets were festooned with these green bags. This summer i have noticed homeowners are cloaking their young trees with the same finery. This is the Treegator Original 20-Gallon Slow Release Watering Bag for Trees and its purpose is to keep vulnerable saplings watered in the dry days of High Summer. I'm glad someone came up with this efficient system, but it does make the tree look rather silly.