DeWitt's Ultimate Thermal Blanket is a 2.5 oz. white, non-woven, needle-punched polypropylene fabric primarily used as a plant protection fabric. Thermal Blanket is designed to let rain and irrigation through to your nursery stock, while holding in precious heat. Due to the fabric's permeability, there is no need to worry about foliage burn, so Thermal Blanket 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. Thermal Blanket also makes an effective alternative for over-wintering perennials and other ornamentals. When it's cold out, choose DeWitt's Thermal Blanket.