We recommend when planting your Full Speed A Hedge American Pillar Arborvitae Trees to use Bio-tone Starter Fertilizer by Espoma. We have tried many so-called “starter fertilizers” over the years and have come to rely on Bio-tone exclusively for our use. Simply mix the recommended amount of Bio-tone into the back-fill soil and water in generously when back-filled. The “good” fungus in Bio-Tone colonizes on the growing roots of your newly planted tree and does not allow the disease-causing fungus to attack the new roots. It has also shown promise in stimulating the growth of the new roots which means a quicker establishment for your plant.