Best source of phosphorus and a premium biological stimulant. Especially good on roses, bulbs, fruit trees and flower beds. We use it in potting soil and when transplanting tomatoes and peppers. also used to coat the surfaces of seed potatoes. contains 30% lime in a compound called bone phosphate of lime. Use up to 2-5 lbs per 100 sq ft; lasts 6-12 months in soil.