Question
What kind of fertilizer should I use for new trees?

Answer
Use 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. Fertilize just before a rain storm and you will not have to water it in. Fertile in the spring and Mid summer.

For the first year I would not fertilize.

Make sure you do not use a lawn fertilizer that contains a herbicide --like "Feed and Weed" type fertilizers. These can kill trees.