Question
I live on a modestly tree'd lot in central NJ and we have several doug firs, blue spruce and arborvitae.  The doug's are mature trees 40-50' tall.  They are healthy but have lost some limbs to heavy snow last winter.  The other trees are third and fourth year nursery stock.

What I need is advise on fertilizing these trees and shrubs.

Any advise you can provide would be appreciated.

Answer
Generally mature tree do not need fertilizing but if you want to yiou can use a general fertilizer-- I would recommend 13-13-13 and sprinle about a pound per inch of trunk diameter around the tree keeping it away from the main trunk about 6 inches. Water the fertilizer into the ground after spreading.