Power Spike Essential Nutrient Spike for fruit trees is specifically formulated to effectively feed and fertilize all types of fruit trees and their common deficiencies. Helps enhance fruit development. The spikes are designed to feed and replenish nutrients to the root zone. Power Spike for fruit trees goes far beyond other spikes by including key elements like Manganese (Mn), Iron (Fe), Magnesium (Mg), Zinc (Zn) and Copper (Cu) for healthy growth. Special binders in the Power Spike safely release the key elements and essential nutrients. Power Spike works underground at the feeder roots to release elements where the trees and shrubs get nourishment. They can not wash away like surface applications. Use 1 spike per inch of trunk diameter (width).