Now that spring flowers have stopped blooming and the new growth has come out, it’s time to trim back the shrubs. This is mostly for aesthetics, but it also helps the plant to rejuvenate and grow stronger. Tree trimming is also okay to do now, but oak trees should not be pruned between April and October. This is when the beetle that carries the oak wilt disease is active; pruning oaks exposes them to the beetles and leaves them vulnerable to infection.
This is also a good time to dead head perennials and flowering plants. Dead heading is taking off the dried, old flower stems. Some perennials will rebloom if you do this right after they are done flowering. Otherwise it makes your perennials look more attractive to take the dead growth off.