Best applied in the spring or the fall, Winchester Gardens Palm Tree Fertilizer Spikes are great at helping your palm trees grow into healthy specimens. Application is simple, just hammer the spikes fully into the soil and let the product work its magic. Encouraging the palm trees to grow beautiful and vibrant foliage, Winchester Gardens Palm Fertilizer Spikes are the epitome of palm tree fertilizer, designed especially to provide for the nourishment of the tree over long periods of time. The spikes are easy and convenient to use as well, being pre-measured doses and directly feed into the roots of your palm trees.