Hello Fellow Readers,
It felt therapeutic to tend to rejuvenation pruning of the Smokebush and other shrubs over the weekend. Rejuvenation pruning is drastically cutting back overgrown plants to restore them to their intended shape. Or, to manage its size, which was the case of my Smokebush (aka Smoke Tree) rising above the roof.
About Smokebush (Cotinus coggygria)
Cotinus coggygria is a fast-growing shrub that bursts into bloom in summer that resembles puffs of smoke, hence the name. It grows ten to fifteen feet tall and wide in Zones 5 to 8 and prefers full sun. They can tolerate a range of soil pH but prefer slightly acidic soil. They fail in soggy soil, so good drainage is essential. Once established, they can tolerate drought.
Mine is a ‘Royal Purple’ Smokebush – one of the dark purple varieties. It lives in part-sun, so it doesn’t purple-up as much as it could. The leaves are greenish-purple, but still, a lovely plant that turns reddish-purple in the fall. It’s a standard, meaning trained to have a single trunk.
How to Rejuvenate Prune Smokebush
To rejuvenate prune smokebush, randomly cut the branches to just above the next growth node (where new stems grow) to lessen the canopy by about one third. To remove a full limb, cleanly cut at a slight angle about a quarter inch from the branch collar. Make clean angular cuts to prevent insects or disease, being careful around the trunks of these beauties as their wood is tender.
You can also rejuvenate clump Smokebush each year to control the size. Cut them to six to eight inches above the ground, much like we do Butterfly Bush (Buddleia davidii). Of course, don’t prune a standard Smokebush close to the ground as it will revert to its clumping natural shape.
The best time to rejuvenate prune is before budding begins in late winter or early spring. Young Smokebush can shoot up odd branches – growing tall before filling out. I suggest pruning the unusual shoots as they come along to encourage thicker branching.
Other shrubs to rejuvenate prune in spring
Other plants I rejuvenate pruned, cutting it to half its size, are the Little Princess Japanese Spiraea (Spirea japonica) and Cinquefoil (Potentilla fruticosa). Like Butterfly Bush, they bloom on new wood and so we won’t miss out on the flower this season. Smokebush, on the other hand, flowers on old wood. Therefore, it will be a few seasons before the revitalized plant returns to its puffy glory of blooms.
Newly installed Smokebush may take a few years to bloom too. But there’s a miracle in the resurrection and new beginnings. It brings hope and trust. Stay well, dear friends. Happy Easter.
Garden Dilemmas? AskMaryStone@gmail.com (and now on your favorite Podcast App.)
Early spring is an ideal time to prune evergreen shrubs like juniper and yews as well as deciduous shrubs that are not known for flowering such as Red Twig Dogwood and Ninebark. Otherwise, the rule of thumb is to prune after shrubs flower. Boxwoods can be pruned anytime through summer (no meatball shapes, please).
Of utmost importance is to not prune plants late in summer or early fall as it may encourage new growth that will not have time to harden off, causing winter damage. Additionally, late pruning stresses plants as they should be putting energy into their roots rather than new growth that time of year.
A previous related column you’ll enjoy Spring Cleanup & Pruning Lavender
To learn about more varieties of Smokebush, click through to the National Gardening Association’s Cotinus Selections.