Northwest product since 1969 for the control of structural moss. Moss-B-Ware® controls moss on roofs, patios, decks, driveways, and walkways. Moss-B-Ware® is recommended for use on wood, composition, concrete or metal surfaces. Very economical, 3 lbs. treats 600 to 3000 square feet and can be used in either dry powdered form right from the canister or mix with water for liquid treatment. Easy application: Just sprinkle product as either dry or liquid on surfaces to be treated and rain does the work. Moss-B-Ware® not available for sale in California.