Always to the frontier

Friday, March 21, 2014

Treasures Of The North And Winter: American Mountain Ash (Sorbus Americana)

Most conversations I have had with people about my northern (i.e. pine tree and really cold winter country) heritage usually include discussions on what exactly grows up in the land of frigid winters and gentle summers.  Many people assume that the farther north one travels, the more one runs into coniferous needle-leaved trees, and that the horizon is nothing but spruce after spruce.  Just as residents of the lower north (southern Great Lakes, Midwest, Northeast) assume that Florida is one giant palm plantation, or that the desert west is nothing but sand dunes devoid of life, residents from said lower north down to the the rest of the continent picture the Boreal north as a land of excellent Christmas trees and the odd moose or bear bursting through the needles.  In truth, spruce are the most northerly occurring trees, right on into the tundra in fact (albeit as a very small form that takes centuries to hit an inch tall).  They are very quickly joined by willows, birch, aspen, and best of all, by something that looks like it should not grow in this land of the anti-leaf, the American Mountain Ash (Sorbus Americana).

Clingmans Dome, Great Smoky Mountains National Park.  North Carolina, with some Tennessee in the background.
 On the upper slopes of Mt. Mitchell, North Carolina.

 As you can see, our friend the grand Mountain Ash looks, like the northern growing sumacs, to be a palm tree that got lost along the way.  Despite growing in an otherwise rugged setting, the tree (others insist it is a tree-like shrub) has delicate looking foliage and a branching structure that looks like it would get absolutely broken apart in heavy snow and ice.  Believe what you want, however, because this fine specimen of a plant really only grows where things get somewhat brutal:

Thanks, USDA!

Most of my pictures of them come from North Carolina, despite the fact that this is indeed a tree I have grown up with for a long time.  The good olf Sorbus is indeed a tree of eastern Boreal Canada, growing right on up to James Bay.  Not until I was specifically plant hunting and noticed it stood out among the Spruce-Fir forests of the higher Appalachians did I really think it was anything unique!  Yes, it has the same good characteristics in both Ontario and North Carolina, and it stands out from the forests in the Laurentians:

Somewhere in the forest north of Brent, Ontario and south of Deux-Rivieres, Ontario.

As well as it does in the Blue Ridge and Smokies:

Off of the summit of Mt. Mitchell in North Carolina.  They really do look weird with the conifers.

Along the main road in Great Smoky Mountains National Park, eastbound side, not exactly sure, but high enough to see the transition between coniferous and deciduous forests.  On the top right there is also a heath bald full of rhododendrons and kalmia!

Yet I always seemed to think of it as part of the scenery, taken for granted.  This is probably because it is not a "northern" looking thing; just as the kid who got excited over pine trees did, so do people who get excited over spruces and rhododendrons which happen to grow best where the Sorbuses do: 

They really do offer a nice foliage effect together.  I am sure by now that any gardeners reading the blog are getting some ideas!  This was taken on the road leading up to the summit of Mt. Mitchell.
Let's face it, you all looked at the flowering Catawba Rhododendron (Rhododendron Catawbiense), and why not?  The Sorbus looks like any old sumac (or worse, a Tree of Heaven [Ailanthus Altissima]) growing in an abandoned city lot might. This holds true until the winter comes, however, and the true glory of Sorbus Americana enters the landscape, it's berries:

Another fine tree from the Ontario Laurentians, probably about 6 or 7 miles from the other one pictured in this post.  Both were set in some fairly dark and lovely spruce-fir forests.
Somewhere in Pictured Rocks National Lakeshore, most likely on the path to Munising Falls near Munising, Michigan.
The berries, of course, are preceded by flowers, which truly makes this an all season interest tree:

Flower buds!  This was at Mt. Mitchell and taken mid June.

Clingmans Dome.  I arrived too early at the high elevations, and too late at the lower elevations, to get a full bloom.
I don't have any photos of the plant in full bloom or naked in the dead of winter with those bright red berries really standing out against the landscape, but it does not take too much imagination to realize that this is a tree which proves that noticeable seasonal changes are not a bad thing.  Indeed, this tree might have even given a bit of a boost to early colonists who had to deal with an actual winter or were heading into the dark and mysterious mountain or northern interior.  It was a welcome splash of color in the winter landscape, and would have reminded them of their own Sorbus back across the sea, the Rowan Tree (Sorbus Aucuparia), which people had considered to be good for everything from making jelly to fighting off witches.  That said, it seems that Aucuparia still gets more notice and stock in the nursery trade; in keeping with the current few posts and their theme on the blog, it is important to note that this is probably because the European version can be grown in warmer spots than the North American version.  Again, however, this is not say that our version is weak and tender, as it can grow out of some really difficult soil:

Somewhere along the Blue Ridge Parkway near north of Mt. Mitchell.

Somewhere on Mt. Mitchell.  As you can see, the soil is pretty shallow before bedrock is reached.  This particular Sorbus is joined by a nice blanket of blue alpine flowers, Mountain Bluets (Hedyotis Michauxii).
And of course, our version can also handle the colder end of the spectrum better than even some of the hardiest northern broadleaved trees.  This tree just happens to be hardy in the other direction, the one that no one claims to like!

By the way, if any Illinois people are reading this, I would love to hear/see anything on the wild population in your state, which is far more prairie than Boreal. 


  1. Enjoyed your post, Brent! Very informative and great photos!

  2. Thanks! Spread the native love; nature can provide inspiration for some pretty amazing garden layouts!

  3. About 2 1/2 years ago, my family and I were walking up the trail to Clingmans Dome, a fall trip September maybe, and I was fascinated by the bright berries. The squirrel in me insisted on pocketing a small cluster of course. Once back home, I planted them in some local dirt and a shallow pot, left out for the rest of the winter. Come springtime, I think a few had sprouted, but I was only able to keep one alive. I potted it up and took care of it, putting it in the ground later that fall I believe. It's grown remarkably well; I just came in from staking it up with some extra bamboo poles. It's maybe 9-10 foot tall already, but it was drooping severely due to the new soft growth and very lush foliage being too heavy. It didn't bloom this spring but perhaps next year I'll be rewarded with that. I'd like to keep it more tree form instead of a shrubby bush, but I'll have to see what it tends towards. I know other trees from the same region can get fairly large, not timber trees, but big enough to support a small bear (snacking away I assume), which we were fortunate enough to spot on the drive up to Clingmans, right along the road. We live just a little ways east of Cincinnati, Ohio (zone 6a). I've never seen this species growing naturally around here, though there's the occasional nursery variety planted (European Mt. Ash I think), but if it's first couple years are any indication, it should do quite well and the birds may even eventually spread it's range a bit. Thanks for the great blog post and photos!