I do not recommend fertilizing a young Japanese maple if it is growing in the ground and doing well. If you do need to feed a Japanese maple growing in a container remember that Osmocote was not designed to go into bore holes. Osmocote should be used by sprinkling it around the base of the plant and then working the product lightly into the top layer of soil. The instructions on the package explain how much fertilizer to use when applied around the base of the plant. If you want to pamper your young Japanese maple add a layer of compost mulch around the roots and keep the plant well watered this summer. Be patient with trees. The first year they sleep, they second year they creep then it is the third year they leap out of the ground. Fast growth from too much fertilizer encourages soft and tender foliage more susceptible to problems.   Keep growing, Marianne Binetti