The mountain ash tree is a very bright and noticeable tree at certain times of the year. In terms of carbon capture, it's not a particularly useful tree, but it has other values. It's colourful and attractive, but even more importantly, it's a great tree to provide food for a lot of birds and animals. The proper Latin name for the mountain ash tree that we plant is the Sorbus americana. Some people refer to the mountain ash as the rowan tree. In Newfoundland, you may hear it referred to as dogberry.
When planting trees for commercial reasons, most people plant conifers such as pine or spruce. When targeting carbon capture, species such as the eastern white pine, red spruce, and eastern hemlock are species that eventually grow to large volumes and which can live for a few centuries. These trees are great choices in eastern Canada, but also have equally beneficial counterparts in western Canada.
However, when targeting the creation of a community forest, other attributes can be beneficial. It's smart to include a number of hardwoods, such as birches, maples, oaks, elms, chestnuts, and other common Canadian species. However, none of these are berry producers. The mountain ash, on the other hand, produces very abundant berry crops.
Here's a photo of a mountain ash tree, heavy with berries:
You probably recognize this tree now. It is common to see these trees in parks and in urban environments throughout eastern Canada and the northeastern seaboard of the United States. Here's a range map from Wikipedia:
These trees, as noted, don't grow to be very large. A mountain ash typically only reaches about 10-12 meters in height (35-40 feet) and the trunk usually only grows to be about 25-30 centimeters wide at maturity (10-12 inches). However, what it lacks in size it more than makes up for in colour and value for wildlife.
Many birds and animals are attracted to this tree. Moose and deer are very attracted to this tree. They enjoy eating the leaves and twigs. Smaller mammals such as rabbits, fishers, martins, and squirrels are also attracted to the tree. Incidentally, completely unrelated to this, I saw a fisher a few weeks ago when I was out looking at a reforestation project. It's nice to see them in the wild.
Birds love the mountain ash for its berries. It's a great source of food for grouse, jays, and many types of songbirds. The berries also stay on the tree quite late through winter, which helps keep many birds alive during cold weather.
In terms of human consumption, mountain ash berries don't have a lot of value. This doesn't mean that you can't eat them. I probably ate them as a child, and probably got stomach aches from them. This is because fresh berries contain parasorbic acid, although this acid breaks down quickly if the berries are dried or cooked. However, people do use them for certain types of food. They're somewhat tart, but can be made into marmalades, jams, and even mixed with mead. If making them into a jam, it may help to mix them with sweeter fruits such as apples. And of course, it is quite easy to make liqueur or tea out of mountain ash berries, although I've never tried either.
Here's a close-up photo of the berries.
Due to the lack of value for carbon capture, we don't plant any mountain ash in our carbon capture plantations. However, we do plant small numbers (1-2% of total trees) in some of our parks and community forest projects.
Here are a few fun facts about the mountain ash:
1. The mountain ash is not a true ash tree. Real ash trees are in the family Fraxinus, whereas the Sorbus family are the rose family. Incidentally, many of the real ash trees across Canada are dying due to the emerald ash borer, but that's a story for another post.
2. A few hundred years ago, pioneer doctors used mountain ash berries as an anti-malarial medicine. There is no evidence that this had any success.
3. After a few frosts, the berries tend to ferment. This is enough to intoxicate birds. So if you see a bunch of rowdy drunken birds, you know what might be to blame!
Here's a link to a CBC article about birds eating fermented berries:
https://www.cbc.ca/news/canada/manitoba/birds-drunk-fermented-fruit-1.4892283
Finally, here is a photo of some of our mountain ash seedlings:
Thanks for reading!
Replant.ca Environmental is a Canadian company that plants trees for carbon capture and builds community forests. We also plant trees in national, provincial, and municipal public parks to mitigate damage from wildfires, storms, insects, and forest diseases. We operate thanks to numerous small contributions from the general public, in addition to larger project sponsorships from businesses and corporations around the world. If you'd like to learn how to show your support, visit our donations page. Even if you aren't able to make a contribution, we very much appreciate when people are able to share our posts or our website link on social media, to help spread the word about the work that we're doing!
Teachers are welcome to use content from this post for their classes. If you know a teacher who might like to use this information, please share it with them! The more that people learn about trees, the better our world will be.
To learn more about the various species that we plant, visit the conifers page or the deciduous (hardwoods) page on our website. Thanks so much for your interest!
Incidentally, our organization is often seeking additional land for our carbon capture projects. Please visit this link if you might know of a recently-harvested property that we could rebuild into a permanent legacy forest.
