The development of osmocote 40 years ago marked the beginning of slow-release fertilizers. The resin-coated tablets contain nitrogen, phosphorus and potassium, and provide all of a plant's nutritional needs for up to two years. When the Sierra Chemical Company developed and marketed osmocote in the 1960s, it was used by nurseries and commercial growers but became available to home gardeners in the 1980s. Osmocote was purchased by Scotts Miracle-Gro in 1994. As of 2010, osmocote products include slow-release fertilizers for houseplants, perennials and vegetables. Osmocote agriform tablets provide slow-release nutrients for trees and shrubs.
Dig a hole twice as wide and as deep as the tree or shrub's root ball. Place the dirt on a tarp.
Remove the plant from its nursery pot by turning it on its side. Tap the pot lightly. Cover the base of the plant with your hand and turn the pot slightly upside down. Pull gently to slide the plant out. Enlist a partner for large trees.
Place the tree or shrub in the hole. Fill the hole with soil to cover the root system. Drop agriform tablets into the hole. Use 1 tablet for a 1-gallon container size plant, use 2 tablets for 2- to 3-gallon containers and 3 tablets for 4- to 5-gallon containers.
Mix the soil on the tarp with 3 shovelfuls of compost. Backfill the hole with soil half full.
Water the hole for 10 minutes to moisten the roots and remove any air pockets. Allow the water to drain.
Fill the hole completely with soil, tamping down gently with your heel to remove any air pockets and prevent settling. Mound the soil 2 inches above the surrounding soil. Water again for 10 minutes.