Spring flowering shrubs like Forsythia, Lilacs, and early flowering Spireas set their flower buds during the summer for blooms in the next year. Prune these shrubs in June to generate new growth which in turn creates new flower buds. On old shrubs try to remove up to 1/3 of the oldest wood, this will cause new growth while your not losing the overall height of the plant. Shrubs that bloom in the summer like Roses, Potentilla, and summer flowering Spireas bloom on new wood. Prune these plants early in the spring, but deadhead them and most will repeat bloom.

• jamie's blog
• Read more