Pruning Smoke Bush*

(Question)

Hi,
I just bought a smoke bush and although it does not need pruning yet, I have been reading about it so I can care for it properly. I came across one of your guides for pruning it. It says they should be pruned in the late winter or very early spring, while dormant. I keep coming across references such as this to “late winter”, “early spring” and each one seems to refer to a different time. Late winter seems to mean different things to different people. So what I’d like to know is what months are late winter to early spring in the GTA, that is if you don’t live close to the lake areas. It would be a great help to have ALL the terms like late spring, spring, early summer, late summer, early fall, etc tagged to an actual month or period. It’s very confusing. When you say late winter, is that late February, March, early April??
Thanks
Maria

(Answer)

Your request for a definition of the various seasons in the GTA is problematic, particularly with the unusual weather patterns we have been experiencing in the last few years. In addition your own geographic location within the GTA will influence the onset of the seasons, whether in an elevated position, a low area into which cold air flows, next to a wooded area and therefore shade, or in full sun. Within your own property there will likely be areas in which the various seasons arrive earlier than in other shaded spots. These areas are often referred to as microclimates.

Observing your plants will give you the clue for pruning or other cultivation. In addition observing plants will alert you to their needs be it pest or disease remediation. For instance many small bulbs emerge early like the winter aconites (Eranthus hyemalis) and the common Forsythia shows signs of breaking dormancy both of which announce that winter is coming to an end.

My own Purple Smoke Bush (Cotinus coggygria atropurpureum) is slow to leaf out. When the buds start to swell is when I prune to remove one-third of the oldest stems down to the ground, remove damaged, diseased or crossing branches, and then prune to shape the shrub.

My own preference is for coppicing (cutting stems down to about 6 inches (5 cm or so) so the plant produces the larger attractive juvenile foliage. This, of course, precludes flowering which is produced on last year’s growth.

The suggested seasonal guide is just that–a guide. I believe that observing your plants will provide the cultivation guidance you need, and you will notice the wonders of new growth emerging, and will be on top of any remediation required.

With your conscientious approach to good garden practice, you are certain to have a wonderful garden. We wish you well.