Q: I would like a good reference book on shrub and tree trimming. I am never sure how much to trim off my plants in the winter.

A: Most pruning knowledge is gained simply by doing it frequently and observing the results but a reference can get you off to the right start.

“Pruning Made Easy” by Lewis Hill is a favorite of mine. “The Pruning Book” by Lee Reich and American Horticultural Society Pruning & Training by Christopher Brickell and David Joyce are good too.

“The Pruning Answer Book” is easy to read and follow and it answers a multitude of questions in simple form.

In addition, the University of Georgia has a good reference called Basic Principles of Pruning Woody Plants.