Mountain Ash in Alberta
by Rob Sproule
One of most common trees around Edmonton, the mountain ash is also one of the easiest to grow and one of the few hardy trees that are beautiful for all 4 seasons. From producing flowers and berries to attracting birds and just plain looking great, they’re remarkable trees.
Growing Mountain Ash
Depending on the species, Mountain Ash are native to either Eurasia or North America. They are almost all in the Sorbus genus, unrelated to actual Ash trees, and are universally easy to grow in Alberta.
Mountain Ash won’t take over the yard, topping out at around 25 feet high with a pleasing, oval shaped spread of about 20 feet wide. They’re gorgeous, with a grey-green trunk and dark leaves along, of course, with their famous red berries.
They aren’t picky about where you plant them, as long as the spot isn’t shady or excessively wet. Give them good drainage and they will establish a broad root system very quickly (their root systems are so wide they are used on mountain slopes to slow erosion).
One of their best features, which us Northern gardeners appreciate more than others, is their hardiness. Mountain Ash are zone 2 trees, so once they’re established they’re tough as nails in Alberta winters. After the first couple years they shouldn’t need any supplemental watering, either, unless it’s exceedingly dry.
For All Seasons
When I tell people that Mountain Ash are a 4-season tree, I often get a quizzical look followed by, “but don’t they lose their leaves?” Not all trees need leaves to be beautiful.
In spring, Mountain Ash produce scores of flat, white clusters of flowers that bloom on the branch ends for a spectacular show. In summer the berries appear in familiar red clusters, contrasting with dark green leaves.
Fall brings a rich crimson flush to the serrated, almost fern-like leaves. It’s one of the most remarkably coloured trees in our zone. Even as winter sets in, the snow accumulates on the blood-red clusters of berries creating dramatic photo-ops on cold winter days.
Throughout the winter, Mountain Ash will attract foraging birds into your yard, eager to partake in the free food. With early spring, lucky yards will be swarmed with thousands of migrating Bohemian Waxwings, feasting on the berries and getting a little tipsy on the fermented sugars inside.
Uses & History
Many people have heard of the Rowan, or Goddess, tree from Celtic and Norse folklore, but they may not know that it’s none other than a Mountain Ash! The Rowan’s mythological and folkloric roots run back through millennia.
Greek mythology tells of the tree sprouting from drops of eagle’s blood, shed as it battled demons whilst recovering a sacred chalice. Each drop became a Rowan tree, its leaves taking the shape of eagles feathers and its berries stained blood red in remembrance.
The Rowan plays a greater role in Norse myth, being the tree from which the first woman was made. More dramatically, it saved Thor’s life when he was swept away by a fast flowing river in the Underworld. The Rowan bent its branch across the water for Thor to grab and pulled him back to shore.