Osmocote Plus plant food would be a great choice for growing your young potted trees. Just add the fertilizer to the top of the soil in the spring and work the granules into the top one inch of soil. The amount to use depends on the size of the pot but a one gallon pot can use one tablespoon of Osmocote or just read and follow the instructions on the label. Osmocote will be released slowly as the plant needs it. Once you transplant the young trees from the pots into the ground just add a table spoon of Osmocote around the base of each tree at the time of the transplant and water the soil. After that your little trees should have a root system that can find food and water on their own. During times of severe drought young trees will still need some supplemental watering. Sounds like you will have a little forest soon. Keep growing, Marianne Binetti