The Old Farmer's Almanac Tree & Shrub Plant Food Fertilizer Spikes are naturally formulated with the essential nutrients your trees and shrubs need to grow and thrive. They feature patented TruSpike technology so they're easy to hammer into the soil without a cap. They will not break, chip or leave dusty residue. Each 5-inch spike is packed with 13-3-3 NPK nutrition ideal as an all purpose fertilizer for all types of garden trees, bushes and shrubs including fruit, deciduous, evergreen, decorative, nut, flowering and more.