Siberian elms are long-lasting shade trees on the Prairies. In my 1950’s neighbourhood, the streets are lined with them, and most of them appear healthy.
Beyond their shade-producing capability, I am not a fan of this species. They are prolific seed producers and the seeds readily sprout all over the neighbourhood. Many of the planted trees have long since died in neighbouring yards, but the progeny of the local street trees remain, often lurking at the corners of yards, behind a garage, or sharing the space with the trash can in the alley. I respect Siberian elm like I respect dandelions and quack grass – for their survivability as a species. From a horticultural perspective, I find them a nuisance.
They are messy, their wood is weak and rots easily, and they can be dangerous for an arborist to climb. In Red Deer, they are prone to leafminer infestation each spring, which can render most of their foliage brown by late June.
On the flip side, they are resistant to Dutch elm disease and European elm scale, so we will likely see them outperform in places like Calgary or Lethbridge.
This is not a species I would consider planting in an average residential yard, but I would use them on acreages or as a shelter-belt tree.
Whenever the chainsaw is sharp! Actually, these trees should be pruned during the same as American elms, from Oct.1-Mar.31, to prevent the spread of Dutch elm disease.
Train as a central-leader standard, with well-spaced scaffold limbs. Subordinate co-dominant leaders. New trees are best pruned annually so they develop a strong structure. On mature specimens, remove dead, diseased, and storm-damaged branches. Remove badly rubbing or crossing branches, if appropriate, but pay attention the size of cut you have to make, and the growth rate of the tree. It isn’t worth it to take off a large branch, just for the sake of rubbing, if the large would will allow decay to form in the tree. Siberian elms readily decay from wounds. Reduce branches as necessary to clear structures, walkways, and driveways, as needed.
(c) 2017 Shane LePage, Wild Rose Garden & Tree Service Inc., Red Deer, AB.