Jobe's GL61100046769 Package 160 Bulk Tree Spikes, Time Release Fertilizer for All Tr Pre-measured fertilizer spikes nourishes at the roots; Time release fertilizer for all trees and shrubs Easy to use fertilizer spikes; No wasteful runoff, no mess, hazards or smells; Apply early spring and late fall Continuous supply of nutrients below the surface, where the active roots are growing Jobes tree spikes are easy to insert around each trees dripline, and the slow-release formula feeds all season No wasteful runoff, no mess, hazards or smells.