Everyone likes to prune in April, but follow these guidelines: Prune spring blooming trees and shrubs only after the flowers are finished. Don’t be in a hurry to prune off brown areas on evergreens. They often will regrow the needles that have suffered winter kill. A light scratch with your fingernail on the branch will show green if the wood there is still alive. If you have fall-flowering shrubs, this is your last call to prune them.