During the summers, I'm often asked about what kind of trees should a homeowner plant. Here are some of my favourite: bur oak, linden, Delta hackberry, Prairie Silk honey locust and Discovery elm.
Bur oak is an under-utilized native tree that really does well when properly planted and maintained in residential yards. People always tell me its growth is too slow, but I tell them to fertilize the tree in the proper manner.
I've always planted a bur oak in every place I've lived on the Prairies. I can usually get one to 1.25 metres of annual height growth. These oaks like the clay loam soils we have in the Red River Valley, and grow quite well if treated properly. It's the best native tree for dry Prairie soils.
There are several varieties of lindens available from southern Manitoba nurseries. Most seem to do very well. The linden has an overall crown that resembles a bee hive, though some varieties more than others. It's one of the more visibly attractive trees, rarely growing more than 12 m high. Remarkably, it's free of serious diseases that affect most other trees.
When a small linden is planted, it's critical that the roots are spread out and not allowed to curl into a root ball. Root curling can cause lindens to self-girdle their trunks when the roots wrap tightly around the base. The tree can die from this effect, or be seriously weakened.
Delta hackberry is also an under-utilized native shade tree that grows naturally at the south end of Lake Manitoba. It's in the elm family but does not have any of the elm's problems, such as Dutch elm disease. Its crown forms a pleasing shade canopy without growing too tall. On our clay loam soils, it will grow up to about 12 m.
Like the oak, the hackberry is virtually free of serious diseases and has only a few minor feeding pests. Its roots are not as aggressive as elms, so it doesn't normally pose a problem for house foundations.
Prairie Silk honey locust is a small tree with outstanding features that clearly make it a candidate for this short-list of great trees. The tree produces horizontal twigs and branches that bear compound leaves having quite small leaflets. Cleanup of fall leaves is simply not a problem as these leaves shrivel up into tiny pieces that decompose quickly. Fall leaves are bright yellow in colour.
The branches tend to be quite symmetrical about the trunk, giving the tree an instant appeal. To date, pests and diseases have not been serious problems.
Discovery elm has Japanese origins but was developed on the Prairies. Its height growth is similar to lindens and hackberrys. With proper care, it's an outstanding tree, tending to produce a flat-topped canopy with a noticeable vase shape.
In a well-spaced cluster of these trees, this effect is visually very appealing, such as in a plaza near the Health Sciences Centre's Buhler Centre on McDermot Avenue. It's my favourite grove of inner-city trees.
Michael Allen is a consulting urban forester, certified I.S.A. arborist and owner of Viburnum Tree Experts. He provides advisory services on trees and shrubs. He can be contacted by calling 831-6503 or emailed at viburnumtrees@shaw.ca
