Dewitt's Thermal Blanket is 2.5 oz. white, non-woven, needle-punched polypropylene material. The Thermal Blanket is designed to let rain and irrigation through to your nursery stock, while holding in precious heat. Due to the frost cloth's permeability, there is no need to worry about foliage burn, so the frost cover can remain in use even on sunny days. This is an excellent product for late fall and early spring applications to extend your selling seasons. It also makes an effective row cover or alternative for over-wintering perennials and other ornamentals.