Nutri-Pak Fertilizer is a revolutionary product that's designed to take care of all worries on how and when to fertilize your plants. The packet has micropores that release just the right amount. This is a balanced blend that is correct for all our great trees and shrubs. 16-16-16 plus sulfur (Fruit, Nut, Flowering & Shade Trees, and Shrubs). Guaranteed for 3 year feeding, but can last up to five years of slow release feeding in some areas. For new or established plantings. One packet for each one inch of trunk diameter for trees. Bury 6-8" deep at drip line. For smaller shrubs (12-18")use 1 packet, two packets for shrubs 2' and up. For older established shrubs over 4', use 3 packets.