Joan Edwards works with a Brooklyn group called the Magnolia Tree Earth Center which has organized local school children into neighborhood ""tree corps,"" and most of the activities proposed here--mulching, making or buying tree guards for protection against dogs and other hazards, notifying the ""tree experts"" when big jobs like pruning are in order, choosing and planting a tree on your own street--are best suited to supervised groups. In its practical way, this handbook has the potential for interesting children in the welfare of city trees; what's needed now is advice for adults on how to make their concern productive.