Living in a City where there are about 3 kinds of native trees, growing something unusual can be a challenge, but not impossible! I have been growing several "out of zone", "that doesn't grow here!" species of trees for many years, and I am always on the lookout for something I've never seen growing here before. Here is a list of my favourites, mostly from my yard, and some I really like but no longer have space for. Staghorn Sumac Rhus typhina
I brought the two I have from the West Coast 15 years ago and they are about 12 feet tall now. They are a small tree growing to around 20 feet tall, in their native range, so I don't expect too much taller in our climate. I love them for their luxurious tropical looking foliage, large frond type leaves that turn a brilliant scarlet, deep- red, given a warm enough fall. After a few years they produce cones of fuzzy red berries that remain thru the winter and for several years after. This tree gets its name from the fuzzy coating on younger branches that resemble the furry coating on a Stag's antlers and maybe from it's open antler-like branching habit. In Calgary protect young trees from Jack Rabbits with a little chicken wire, give extra water during dryspells in the summer and fall, mulch roots and give the base any extra snow we have during the winter. As these trees mature they produce many suckers so if planted in a lawn one can simply mow over the young shoots or plant in an area where it can't sucker. I let the suckers grow for a year and separate the following spring into individual trees to give away. I have never had a pest problem with these trees, they can take a little hail and in early July when the greenish flowers form they are loved by masses of bees. All round my favourite underused ornamental for this region!
Pagoda Dogwood Cornus alternifolia
I must admit I had little faith in this plant for many years! In Calgary this is slow growing and prone to winter kill especially when young, however, given enough patience they are very rewarding. Like many dogwoods they are perfectly adapted to growing under larger trees and in fact in Calgary this situation seems best, mine grows under a large Mountain Ash. After more than a decade this small tree is almost 8 feet tall and now produces the creamy white flowers and blue-black berries one sees in pictures. The branches are green and the leaves, very similar to Red Dogwood, are bigger. Also, like it's native cousin, Red Dogwood, these guys turn red, purple, orange, and yellow in the fall. The berries unfortunately do not remain thru the winter, they seem to be a favourite food of migrating Warblers in the fall. I do not think these trees would enjoy a dry location in Calgary, they like to have plenty of water all summer especially when young.
Crimson King Maple Acer platanoides
On a trip to the Okanagan around 11 years years ago I dug up a small red maple seedling from beside the highway, today it has reached a height of around 9 feet in my Calgary garden! It has had little winter kill but seems to do just fine now that it's established. A few years ago, working at a local greenhouse, we carried a Crimson King Maple variety that descended from one grown in Lethbridge, so I believe they can grow in our area with some care. I don't have any special tips for this tree, other than as for all these Eastern and warmer zone plants to supply plenty of extra water in the summer and fall leading into freeze up. I sometimes press the leaves in the fall, they are just like the ones on the penny!
Amur Cork Phellodendron amurense
I've been growing this for 15 years in my front yard, yes, it is pretty slow growing but well worth it! There is an Amur Cork at the Calgary Zoo that is probably over 15 feet tall on the South side of the Botanical Gardens. I don't know why I don't see more of them in Calgary as they are good with a hot and dry location, never have pests, and look sub-tropical! They do sometimes flower in a tiny grape-like cluster but won't produce berries or fruit as a male and female are required for pollination. I have never seen a very old specimen of this tree but apparently as they age they get a very furrowed and chunky bark that resembles the actual tropical cork tree. They hate root disturbance so don't plant near a place you dig frequently. I had to give this tree plenty of water when it was younger but now that it has established it seems fine near my south facing sidewalk where it gets very hot in the summer.
Amur Maackii (Maackia) Maackia amurensis
So, I had one of these for several years and lets just say there was an unfortunate herbicide accident and it is no more, one of the worst things to have happened in my horticultural life. Be that as it may, what a pretty little tree that I never see! There are a few young ones at the Calgary Zoo if you want to see one though. These trees are related to caragana but don't let that sway you, it's nothing like that horrible prickly standard of the prairies. The delicate leaves fold upward slightly when the sun gets very hot, similar in appearance to a honey locust but would never grow that big. The creamy white hay-scented flowers did not appear until late August or even September in my garden so I don't think it would ever produce the pea-like pods with seeds or become invasive in our area. It is definitely worth a try in a hot and dry location with plenty of sun. It is another moderately slow grower so get the biggest one you can find!
Amur Maple Acer ginnala
What's with all the "Amur" in the Latin name??? Well, the Amur River is what separates China from Siberia so just imagine why plants from this cold area do well in Calgary! Amur maple is certainly another one of these well adapted to our cold winter and short summer climate. If you miss Japanese Maples from the nicer climates of Canada this one is pretty close, in fact this Maple is used in the Japanese Gardens in Lethbridge. I was inspired by the Japanese Gardens and, over the years, trimmed mine into a sort of Bonsai look. These trees grow tremendously fast, so buy a small one, I have to maintain the shape with trimmers at least 3 times a year. Given the massive growth I have only seen them at maturity in our area at around 20 feet or so, a relatively small tree with a natural Bonsai look if left to grow naturally. They are extremely hardy and one of the first to leaf out in the spring, followed by masses of tiny white flowers that become bright red samaras (Maple seeds), don't worry though I've never had any seedlings here although in other Prairie Cities they seem to grow from seed quite willingly, like that's a problem? In the fall the leaves turn many shades of yellow to deep red. These trees can be prone to iron deficiency so apply some chelated iron in growth although I have read if the soil is dry and not too heavy with clay they will be fine. Very well adapted to hot and dry sites once established and can be pruned into any shape you desire, would look good planted in front of the character below...
Bristlecone Pine Pinus balfourianae
In a City where it seems like 80% of the big trees we have are either Green, White or Blue Spruce I think Pines are a more interesting way to go. Bristlecone Pine strikes me as one of the most unique of Pines that can be grown here. These trees are really something, one of the longest lived in the world, the oldest recorded at over 5,000 years. I have not grown this tree in my yard but they seem to be gaining popularity all over the city. Although initially expensive to buy they seem to grow moderately fast and are well adapted to Calgary's climate, in fact they are native to the high mountains of the Southwestern U.S. Most of the Bristlecones we see around the City look no more than a decade or so old but I did find a few in an older neighbourhood that could be 50 or more (bottom photo) years old, these trees are probably at least 20 feet across and 30 feet high so plan accordingly! If you are familiar with the Monkey Puzzle Trees of the West Coast you might call them a lookalike, well, it's about as close as we are going to get to that sub tropical species!