Tree Care Articles

My articles page is the place where I have written about most aspects of arboriculture in Calgary. Everything in an arborists' trade, from tree care, trimming and pruning, arbor care, and even being a tree doctor. There are over 150 separate tree resource articles arranged alphabetically. Whether it's, "a mindset for healthy trees" all the way through to "yellow leaves", most of the important aspects of Calgary tree care are included. Have a look, prairie hardy fruit trees, selecting evergreens, tons on planting and pruning, please enjoy this free resource.

If you'd like to take a deeper dive into the internal workings of trees, check out my Botany Talks.

The Mountain Ash

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Written by Kevin R. Lee Kevin R. Lee
Published: 06 April 2018 06 April 2018

The genus Sorbus, the Mountain Ash, is one of our favorites. About the only minus score on these Trees would be a rather unpleasant flower aroma, but that's about it. Hortus Third speaks of 85 species in the northern hemisphere. I will mention six or seven varieties. Deep in European cultural roots are the Rowan Tree and the Whitebeam.

Calgary does not have a native Mountain Ash, the closest being the western Mountain Ash, S. scopulina. The next closest is the Sitka Mountain Ash, S. sitchensis, from the west coast and rarely in the Alberta mountains. The most common Mountain Ash in Calgary is the American, S. americana, the European S. acuparia, followed by its cultivars, the Rossica, and the Black Hawk. Next would be the Showy, another eastern Canadian Tree. The last one we will discuss is the Oak Leaf Mountain Ash, a hybrid, S. hybrida. This Tree has a single leaf rather than the classic Mountain Ash pattern.

The American Mountain Ash is native through the southern half of Ontario and Quebec and throughout the Maritimes. This is the Tree commonly planted in the west because of its overall hardiness. After decades they can attain a great size and there are fifty-footers out there. More commonly they are thirty-plus feet high and multi-stemmed. A classic form, easy to climb, it attracts children and arborists alike.

The European Mountain Ash is similar in size and form to the two native Americans, the main visual differences being the orange berries and a lighter colored bark. Whereas the bark of the American is a dark greenish brown, the European is more of a tan color. The European has been the choice of plant breeders and there are two good cultivars. The first is the Rossica, a good Tree with a much narrower growth form, close to being a Fastigiata. If you love Mountain Ash but do not have a lot of space, this might be your choice.

The Black Hawk is another good choice for space limitations, sold as a smaller Tree. This cultivar is the newest and therefore somewhat unproven.

The Showy is very similar in form to the American. It derives its name from having the most robust of Mountain Ash flowers. It is not easy to distinguish from the American.

Last to mention is the Oak Leaf Mountain Ash, again a relative newcomer. The leaf is very attractive. This Tree is designed to be more columnar.

Bugs and diseases
Good, naturally strong Trees, the Mountain Ash is mostly trouble free, especially if regularly watered. That said, they are all pome fruit bearing, and subsequently can and do get fire blight. Every species has slightly different looking symptoms. Look for a set of dry brown crinkled-up leaves. As the larger branch starts to die, leaves turning yellow will be present. Further symptoms are cankers and large dead branches, I sure hope you catch it before that. Treatment is a thorough pruning.

Mountain Ash are also susceptible to a fungal disease called Silver Leaf. The fruiting bodies are white and resemble small sea shells. They exude a toxin. When I find these I scrape them off down to the wood. This seems to help. The wood they are present on may be dead.

Europhytic mites prey on Mountain Ash. They do no significant damage. Sometimes called Blister mites, their inner leaf activity causes small pockets to form on the leaf surface. Undersides of leaves will present small tan felty spots. You can spray with dormant oil before bud break to help control them.

Mountain ash tree
Green ash tree

Ash Trees

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Written by Kevin R. Lee Kevin R. Lee
Published: 04 April 2018 04 April 2018

The ash is an important eastern hardwood that is steadily moving west.

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Septoria canker

Septoria Canker on Poplar

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Written by Kevin R. Lee Kevin R. Lee
Published: 04 April 2018 04 April 2018
- Found on a variety of poplars across North America
- Hybrids and non natives hit worse
- Also present in natives and aspens
- Leaf infections occur soon after attaining full size
- More conspicuous on lower branches
- Leaf spots approximately two months later, pencil size black spots
- Cankers on leaf affected trees
- Canker diseased bark is black, often brown toward center of canker
- Shoots may be girdled, lower branches mostly affected.

(Photo credit: “Septoria apiicola a1 (2)" by Jerzy Opiola (Selso), licensed under CC BY-SA 4.0.)

Forsythia blossom

Forsythia

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Written by Kevin R. Lee Kevin R. Lee
Published: 03 April 2018 03 April 2018

Forsythia is one of my favorite shrubs, the first woody to flower; when you see these warm golden blooms you know that spring is here, as sure a sign as your first gopher and crocus.

Quite large in maturity, approximately ten by ten feet and a little gangly, they are similar in appearance to an unpruned Villosa lilac. Because of its size, plant it closer to the back of your garden bed.

Northern Gold is our best variety.
Manchurian ash tree

Two Failures, Griffin Poplar, Manchurian Ash

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Written by Kevin R. Lee Kevin R. Lee
Published: 03 April 2018 03 April 2018
The Calgary environment is a serious place to be a Tree. To survive here, Trees will have to be zone hardy, pathogen resistant and, yeah, lucky. See my Calgary from a Tree's perspective entry for more.

Because of this, the prudent new Tree buyer waits, finds a appropriate choice from varieties that have proven them selves over decades of testing. Let those who like to buy lots of new Tree varieties do so. The metaphor I want is the hockey team; in this town you'll never win a game unless your first string players stay on the ice. Let the grinders sit on the bench, the game's too tough.

The Griffin poplar breed at Brooks did not exhibit the winning characteristics that are required here. First, its immune system had been seriously compromised by the crossing of its parents' genes. The Tree was the all time champ for fungal canker susceptibility, cytosporia and septoria, both of which can be pretty nasty with hybrid poplars damaged this Tree severely.

The tree's form was the other problem. One of a long line of Trees manipulated to look like the classic Italian Lombardy poplar, its major trunk sections were poorly attached to the trunk and most attachments had large included bark sections. Included bark can be dangerous when we are talking about a 60 foot multi-stem poplar. Sold as the latest and greatest next best thing in its day, now there are very few left. I can not think of where one is or the last time I saw one (assume that as I move around the city everyday that I am doing a constant Tree inspection and inventory). Its distant cousin, the Swedish columnar aspen may be headed in this direction.

The Manchurian ash was very popular in the 80s and 90s, new untested, it was a beauty.With some of the thickest, shaggiest looking foliage, all round a handsome Tree. Related to the Green Ash, but nowhere near as tough, it seemed that we had got a new Tree. I went to Eagle Lake myself and made my selection, a gift for my parents. All went well the first few years, good growth, no problems. Constantly nagged about Tree care by his son, my father took optimal care of his new charge.

Then came the winter of, I believe 1996, a winter full of Chinooks and extremes. Spring approached and, as all Tree lovers, we waited, hopeful, would our Tree make it ? Finally it leafed out full and beautiful, a wonder... on one half of its crown. The other half was stone dead. The freezing and thawing repeated through the winter had taken its toll. Any who did survive were a few years later devastated by the Cottony Ash Psylllid, as was the Manchurian's cousin, the black ash. I don't think anyone is planting either of these Trees today.

A third quick mention would be the Columnar Siberian crab apple. Bred from some of the toughest apple stock on earth, the cross to make the column cost this Tree its immune system. I have seen them die in droves. it has the highest fire blight susceptibility and the weakest defense of any apple I have ever seen.

(Photo credit: “Fraxinus mandshurica kz01" by Krzysztof Ziarnek, Kenraiz, licensed under CC BY-SA 4.0.)

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