Red osier dogwood

(Question)

I have an odd situation with a red osier dogwood and am hoping to get the benefit of your expert opinion. The dogwood has lived in my tiny north-facing front yard in downtown Toronto for about 5 years. Over the years, I’ve pruned off dead branches and branches that extended over the sidewalk, without any attempt to maintain the red colour of the stems. The result now is that the shrub looks more like a little tree (approx 9 ft high x 8 ft wide) – photo attached. Although there’s no red colour in the trunk and main branches which is what most people seem to value in the red osier, the shrub tree is rather pretty and does provide a privacy screen along with the usual small white flower clusters and white berries. My two questions are: Does it make sense to grow the red osier dogwood as a tree (giving up on red colour) or does that go against the plant’s nature? Can I still return it to its normal shrub form by pruning? Thanks very much for considering my questions.

(Answer)

Thank you for contacting the Toronto Master Gardeners.

Your red osier dogwood certainly looks healthy and does provide nice privacy and interest with the flowers and berries in your front garden. Most woody shrubs as well as some vines such as wisteria or trumpet vine can be pruned and trained into a tree-like shape. In fact, I have a Hydrangea paniculate ‘Pink Diamond ‘shrub which I have pruned to resemble a tree.

Pruning woody shrubs so that they resemble trees or keep them as shrubs is a personal preference. In my case I trained my hydrangea into a tree since I did not have the space in my garden for a multi-stemmed shrub. Another advantage of training shrubs into trees with a single stem is that you can underplant with ground cover or low growing perennials as long as you limb up the lower branches. And who doesn’t like more space for more plants!

Red Osier Dogwood (Cornus sericea) grows best in rich, fertile consistently moist soil in full sun to part shade however, the bark will be brightest if grown in full sun. The best colour is on young stems so consistent pruning every 1-2 years is required by selectively removing about one third of the oldest stems at ground level. This method of pruning will ensure a vigorous shrub with bright red winter colour.

If you do decide to rejuvenate  your dogwood you must remember that it will take at least two years for your shrub to fill in and produce new growth. According to the Chicago Botanic Garden’s article on Winter Pruning  “When you opt for this process of going medieval on the plant, it actually spurs the complete, new regeneration of the entire plant above ground. Yes, at first it will just sit there, apparently doing nothing, and looking like a goner. But give it time. What you don’t see is the plant figuring out that it needs to develop new shoots, which will bud right out of the stubs you left behind. Just leave them alone and water the shrub if rainfall drops below 2 inches per week. And it’s always best to give it a couple of good, deep waterings per week rather than spotty, shallow daily passes with the hose or sprinkler.”

Here’s to many years of enjoyment of your red osier dogwood.