River Birch tree bedEverything changes. Our whole life is changing, but there are smaller changes in the world, like changes  in cultivation rules, come to all gardeners with some regularity. We have been planting trees and shrubs in Greenfield and have followed new rules, and rubbed up against others unhappily. One old practice, if not a rule, about planting trees was that you could leave on the wire cage if it came with one, and that you could…