Jobe's Palm Tree Fertilizer Spikes, 10-5-10, 5-Pk. are specially formulated to provide palm trees with the primary nutrients needed to enhance their beauty and promote growth. Unlike surface applied fertilizers that can wash away with rainor watering, Jobe's spikes work underground at the plants feeder roots to provide nourishment where it's needed. With no mixing or spreading necessary, the premeasured spikes make for a fast, easy and mess-free fertilizing experience. For best results, apply twice per year between March and October.