When to prune back shrubs like butterfly bush, roses, and bluemist spirea?

Blue mist spirea, Caryopteris x clandonensis

Q: Can I prune back shrubs like butterfly bush, roses, and bluemist spirea in the fall or should I wait until spring? What about clematis vines?

A:  Trees and shrubs store energy in their stems and buds during the winter, to be utilized in the spring as the plant breaks dormancy.   Heavy pruning in the fall removes that stored energy and can affect the plant’s ability to survive the winter or leaf out properly in the spring. 

Tall, whippy branches could be subject to breakage during the ravages of winter storms and would benefit from a light pruning in fall.  Any shrubs or trees that bloom in the spring before Memorial Day have already set their flower buds for next spring’s display, so any pruning in the fall will be removing spring flowers. Prune back clematis vines in late winter.