I know it's a bit wild and windy out there this week, but it's time to think about annual pruning of Cotinus.
It's been so mild this winter that they will be budding before we know it, so to save them wasting energy, get out there now and cut them back hard.
Why so hard? If you cut them back to a framework, much as you do for climbing roses, or for spur-fruiting trees, you will be rewarded with much larger foliage, and it will be much closer to the ground, so everyone can benefit from seeing it. It also serves to keep the plant within reasonable bounds - if left uncut, they get bigger and leggier every year.
I've attached some photos: the first two are showing one of the Cotinus shrubs in my care: it's quite a large one, about six foot tall, and over the last 14 years I have been cutting it back every year, as though it were a fruit tree with fruiting spurs. You can see how all the very short cut stems make a “knobbly” end to each large, solid branch.
I also take this opportunity to remove any obviously dead twigs or small shoots, and to rake out all the dead leaves and other debris that get caught in amongst the stems.
The third photo could well be captioned “how to rejuvenate an overgrown, leggy Cotinus: year two” as it shows one horizontal branch that I cut back hard at this time last year, and have just cut again this year. You can see that in this case, there is the one “main” branch: this is the one that I chopped last year, making just one straight cut across and leaving a simple, bare stump. It produced six or seven good strong branches last summer, each of which was well over 6' long, and now I have cut them back to just 3” or so each. This time next year, I will cut back all new shoots on those 6-7 branches to just 1-2” and lo! and behold, there you have it, the start of “knobbles”.
(In case you are wondering, no, this is not the one and only branch of the Cotinus in question, it's the only one of which I have a photo!)
It is often said that if you cut back a Cotinus hard each year, in order to get better foliage, you won't get the flowers, and it's true that, generally speaking, the flowers only appear on older wood, but in my experience there are two answers to this, one is that you don't always get flowers on a cotinus anyway, it has to be a long hot summer: and secondly if you really want flowers, then only cut it back every second year.
And my fourth photo is a simply joyous one of a "Goth Bouquet", made of Cotinus coggygria 'Royal Purple' foliage and flowers: stunning, isn't it!