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Arborist Insights

Jan 01
0

Winter failure of co-dominant stems on maples

By | Arborist Insights, Landscaping | No Comments

It was yet another snow day. Just before Christmas.  En route to a snow clearing session, we got a call to check out a damaged tree. So we turned around. Only the one damaged tree turned out to be eighteen. Mostly maples (Acer). It was shocking to see the trees fall apart after snowfall, overnight freezing and morning rain. The damage was recent and branches were snapping as we spoke to the garden liaison. She was clearly distressed and eager to speak to an arborist. I didn’t have good news for her.

Let’s examine the Acers on site. They clearly had lots of co-dominant stems with included bark. Why is that so bad?

  1. C0-dominant stems are not proper branches. Proper branches have several layers of overlapping wood a their junction points. Some of this wood is produced by the trunk and some of it by the branch. This means that the point of attachment is very strong!
  2. Included bark is a problem. Imagine two stems growing as if they were the leaders. They grow by producing bark, cambium, phloem and xylem. As the two stems grow bigger, some of their bark gets buried inside the junction. This only weakens the junction point and increases the chance of failure.
  3. Normal branches have bark protection zones. These are areas inside the wood, near the branch-trunk junction. They are rich in protective chemicals that help to prevent pathogens from reaching inside the trunk. So, when kids snap a branch on the way from school, the protection zone does its job of sealing the trunk from pathogens. Co-dominant stems lack these protection areas so diseases can travel down to the trunk. This also makes it difficult to remove one stem because the wound won’t get help with keeping disease out. Normally it would be good if you could prune one of the co-dominant stems right out.
  4. Trees with damaged co-dominant stems often die. The wounds are horrific and because they lack bark protection zones, pathogens, fungi and pests get in.

It turns out, maples are known for co-dominant stems. The site we were on looks very different after the costly removal of eighteen trees. What can you do? Port Moody hasn’t seen this much snow in a long time.

Day of failure pictures

 

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Two co-dominant stems. One is gone. The wound is large. The tree got removed.

 

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There is no comeback from this wound, even if you had a bark protection zone.

 

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Always consider safety! This Douglas fir (Pseudotsuga menziesii) branch came down five minutes after we arrived.

 

Post-removal picture

 

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Dec 16
0

Vancouver Tree Book

By | Arborist Insights, Books, Reviews | No Comments

Vancouver Tree Book by David Tracey is now available in bookstores. Normally I would wait for Amazon to ship the book but I didn’t want to wait. Not for a new tree book. I picked it up from Chapter’s for $21, tax included. Not bad.

It’s pocket-sized and features 100 trees. It will easily slip into your backpack. One nice touch is that we are given actual City of Vancouver spots where the trees can be seen. There is also a list of 10 treasured trees in the city.

The illustrations are very nice. Since this is a pocket guide, only basic information is presented. After scanning the guide, it’s clear I still have some work left to do on my tree identification skills. Not to worry. I will get there. I’m an arborist just like Tracey.

Having discovered Acer campestre in Langley and nowhere else, I was relieved to find out that there are plenty of specimens in Vancouver. My favorite tree, Albizia julibrissin is also in the guide, which means the guide automatically gets a passing grade.

The guide makes references to an earlier book on Vancouver Trees. Trees of Vancouver by Gerald B. Straley we learn is now out of print (I have a copy!) . Sadly, the author has passed away. That makes my copy that much more precious.

Unlike Tracey’s pocket guide, this is a bigger book that covers over 470 trees and includes leaf drawings. In the middle are 86 beautiful color photographs. Location information is also given which makes it easy for you to locate your favorite species. Tracey obviously copied this handy approach.

 

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New and pocket-sized, 100 trees

 

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Information on 470 trees, now out of print

Summary

This is a handy guide for all green professionals. It’s well worth $21. I will now go through it and scan it for the species I don’t yet know well. I hope you do the same.

 

Nov 18
0

Abiotic tree injuries: girdling

By | Arborist Insights, Landscaping, Strata Maintenance, Tips | No Comments

Tree girdling

As landscape supervisor and arborist I reported for duty one fine spring day in White Rock. The request was to check on a dead Acer palmatum tree. Great, let’s see. What I found was a classic example of abiotic tree injury: girdling. In this case it was caused by an overzealous bird lover. The bird feeder string was left in place too long. Once the tree grows and “swallows” the string, there is nothing we can do. Nothing.

Tree girdling leads to two huge problems:

a) It restricts the flow of water and nutrients up the tree. The branch above the constriction eventually starves and dies. See the pictures below.

b) Trees fail at the point of constriction.

 

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This tree owner is a bird feeder fanatic. Top area is clearly dead.

 

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The only life is below the girdling zone where water and nutrients can reach.

 

Forgotten pines

 

Sadly, it got worse. An adjacent property has a long wild zone fence line. Hidden in the vegetation are staked pines. Staked and forgotten. The result is the same as above or worse, where the whole pine expired. I presume the pines started leaning and someone staked them with ArborTie. This material replaces wire and hose, it’s cheaper, safe, soft and simple to use.

But in the case below the arbortie was incorrectly tied with knots and left. Since the pines were leaning, there was no “play” on the arbortie. It should be checked periodically. Remember this is a low-profile wild zone between homes and a city park.

 

 

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This pine was one of many; staked and forgotten.

 

Action steps

What can we do? Nothing against birds but tree owners should be discouraged from installing bird feeders on their trees. But if they must, then let’s at least use appropriate materials and check on the install periodically to prevent girdling. We can’t reverse girdling.

 

 

Oct 10
0

Yours to discover: Acer campestre

By | Arborist Insights, Landscaping, Species | No Comments

First encounter with Acer campestre

Working in Langley, BC on an early spring day, I noticed a low tree branch obstructing an entrance. This is called ‘landscape eye’ and the subject of an earlier blog post. So out came my snips and the branch was cleared out of the way. In seconds. Then the ‘bleeding’ started! In seconds. Oops. I noticed the samaras and only then realized this was a maple tree. The actual species name escaped me because this was our first encounter. I would later look it up and a blog was born.

 

Maple rule

Maples are ‘bleeders’. They lose large amounts of sap when pruned at the wrong time. This is the maple rule: prune before Christmas or in summer. This was early spring so the sap ‘bleeding’ was noticeable. One week later it had stopped. Thankfully.

If you prune in summer, make sure it’s not under drought conditions. Under drought conditions, trees close their leaf openings to avoid water loss. This means that carbon dioxide can’t enter and food can’t be produced. The tree lives on reserves stored in its branches. If you prune too many branches off, you can starve the tree.

 

Field maple details

Campestre means ‘from fields’. It is an attractive medium-sized deciduous street tree. It tolerates urban conditions like drought, clay soils, air pollution and soil compaction. It prefers full sun to part shade conditions. It has yellow fall color and can be pruned, sometimes even harshly. In Europe it’s shaped into hedges.

The leaves have five blunt lobes.

This is a low-maintenance street tree. The only work I have done on these trees is walkway clearance. I have yet to encounter this maple species on other sites.

Have you seen Acer campestre?

 

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5 lobes and samaras

 

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Not much work to be done on these trees, other than walkway and house obstruction

 

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City street location with plenty of sun

Sep 13
0

The Hidden Life of Trees

By | Arborist Insights, Education | No Comments

The Hidden Life of Trees .

German author Peter Wohlleben will appear at the Writer’s Fest in Vancouver this coming October. This sounds very interesting. The Writer’s Fest run from October 17-23. The book will be published in English this September! I can’t wait. Greystone Books.

 

The Hidden Life of Trees

 

 

Tuesday October 18, 2016 10-11:30 a.m. Waterfront Theatre.

Peter Wohlleben spent more than 20 years working for the forestry commission in Germany before leaving to put his ideas of ecology into practice. He now runs an environmentally-friendly woodland in Huemmel, Germany, and also teaches and writes about woodlands and nature conservancy. His latest book, and English-language debut, is the international bestseller The Hidden Life of Trees, a collection of fascinating stories, supported by the latest scientific research, that reveal the extraordinary world of forests and illustrate how trees communicate and care for each other.

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Peter Wohlleben’s appearance is made possible by the Goethe-Institut.
For tickets visit http://writersfest.bc.ca/2016/program-guide or call 604-681-6330
Aug 26
0

“Lab girl” book review

By | Arborist Insights, Books, Reviews, Species | No Comments

“LAB GIRL” by Dr. Hope Jahren is a fantastic book! That is, if you like plants, science or you are considering a career in academia. I purchased the audio version and listened to the book during my weekend work sessions. Dr. Jahren’s Ph.D. dissertation was about a tree. Her work focuses on plants and their longevity. Paleobiology.

The chapters nicely alternate between personal life and science. I openly confess to enjoying the science chapters more. It seemed like there were too many lab set-up references. But this connects to Dr. Jahren’s constant side-kick, lab researcher Bill. The two are inseparable. After finishing the book you might feel the urge to visit with Bill. He is a pretty interesting character.

Key idea 1: If you want to make it in academia as a female Ph.D., get ready for a bumpy ride. Male professors have doubts, funding and grants are a constant headache. This book should be required reading for any female considering a career in US academia.

Key idea 2: Plants, especially trees, are incredibly fascinating. I already knew that. You will, too, after reading “Lab girl”. Consider the case of resurrection plants. They are so brown and dry, we would consider them dead, and toss them. But wait. A bit of moisture brings them back to life. This can repeat many, many times, until eventually they do die. These are the only plants that have figured out how to grow without being green!

Seeds are also amazing. Alive, they can wait for hundreds of years before taking a chance and emerging. Their one chance. What exactly triggers it?

Key idea 3: The book closes with a personal request from the author to plant a tree at your home. If you can. The planet is losing green cover every year. This small act of planting a tree or two will help.

Key idea 4: To learn more about trees, Dr. Jahren recommends Peter A. Thomas’ “Trees: Their Natural History“, about $50 from Amazon.ca. By the time this blog post is published, I expect to have it finished. In paperback form.

The book has a happy ending. Hope marries, has a child and the family settles in Hawaii. So does Bill. Of course. I love plants so I give it 5 stars out of 5.

 

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Jun 17
0

Love note for tulip trees (Liriodendron tulipifera)

By | Arborist Insights, Landscaping, Plant Species Information | No Comments

It’s early May and tulip trees are hard to miss on one of my Maple Ridge strata sites. Liriodendron tulipifera (family Magnoliaceae) are eastern USA natives. In landscapes they are used as shade or lawn trees. They are large trees and therefore need ample space. Always consider your tree’s mature size. They are fast-growing trees but weak-wooded. This may be part of the reason why tulip trees are not recommended for street tree use. Then there is the size issue.

A little twist

Tulip trees bloom from May to June but there is an interesting twist. Trees usually flower and then leaf out. Cherries, for example, put on a great show, fade and then green foliage appears. Show is over. Tulip trees flower as they leaf out and since the cup-shaped tulip-like flowers are borne high in the trees, they are easy to miss. Not for me. Armed with this knowledge I was able to shoot my own flower pictures for this blog.

 

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Tulip tree leaves also have an interesting tulip-like appearance. Together with the tulip-like flowers, it makes it easy to remember the common name. But remember it’s best to learn botanical names. You will be glad you did. Sometimes I find it amusing how both leaves and flowers are tulip-like. The actual leaf-out mechanism is  interesting but difficult to describe.

 

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Tulip trees like full sun and tolerate moderate drought conditions. In dry weather interior leaves turn yellow and fall off. This is a response to weather, not a disease.

One problem

One annoyance with tulip trees is aphids. When aphid infestations are large lots of honeydew secretions appear on the leaves. These provide the growing medium for sooty mold fungus. Usually there is little permanent damage to the tree but it is annoying. Mrs. Tushman goes out to get her latte and the family Porsche is covered in sticky secretions. Then the world is close to ending.

 

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Aphids

 

Tulip trees are gorgeous trees. Spot them in your neighborhoods. Plant them if you are lucky enough to have the required big spaces for it.

May 06
0

Redneck tree removal

By | Arborist Insights, Landscaping, Strata Maintenance | No Comments

It’s always sad to see trees die on site. Any site. In this case we had three birches (Betula papyrifera) killed off by the bronze birch borer. Birches are shallow rooted and can suffer in heavy heat of late spring and summer. At this site the birches had little room and suffered from reflected heat as well. Drought can lead to dieback at the top of the tree and the bronze birch borer is an expert at detecting  weakened trees. Weakened trees are very attractive to this urban pest. Once the tree is attacked, there is very little hope of saving it.

I was on site to install cedars (Thuja occidentalis ‘Smaragd’), Cotoneaster dammeri and Hemerocallis ‘Stella d’Oro’. The heavier tree work was left for last.

Since birches are shallow rooted and the ones on our site were not extremely mature, we decided not to bother with stump grinding. So here I introduce redneck tree removal. Don’t try this at home. Hire certified landscapers or arborists. Please.

 

Step 1

Remove most of the crown with chainsaws or handsaws. Safety is important here! This strata complex corner was used by cars, residents were washing their cars and kids were playing outside. Wear proper protection if you choose to use chainsaws. Always.

 

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Step 2

Cut notches into the tree so the chains have some place to bite, otherwise they will just slip off under pressure

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Step 3

Attach chains to the tree and to the back of your truck, then drive very slowly until the stump is completely out. Use good chain link fasteners. Common locks could blow out.

 

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Step 4

Remove all stumps and fix the lawn area. We used lawn and garden mix soil from a landscape center. Good quality seed also helps.

 

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Mission accomplished. The site will miss the many ecosystem services the birches used to provide, especially summer shade for the adjacent unit.

Apr 22
0

Final cut: remembering arborist Jody Taylor

By | Arborist Insights, Events | No Comments

Cherry blossoms are bittersweet. They are beautiful but they don’t last very long. Like life. Out on a walk with my kids one day, I snapped a photo of  spent cherry blossoms on top of moss and the bittersweet idea popped up again.

 

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Then the news broke. The City of Vancouver lost one of their most experienced arborists in a work place accident. I never actually met Jody Taylor (1974-2016) but I know people who had worked with him for years; and they are sad. Devastated. He was a total tree professional. The City of Vancouver arboriculture department will never be the same. As a certified arborist I feel their pain. It’s a tragic loss for all green professionals.

Sometimes a cut can go wrong. I don’t fall trees personally but let us say there are two cuts to make. The front notch and the back-cut which drops the tree. When everything goes well, the trees falls over and crashes to the ground. Done. Next.

But as I recently found out, when the cut goes badly the tree can “barber-chair“. When the back-cut is nearing completion, the tree cracks and splits, sending the back end violently up. The tree then snaps at the end of the initial crack and who knows where it falls.

Speculation was that Jody’s back-cut didn’t go well. Pruning Catalpa trees in an elevated bucket, it would appear, from what I heard, that Jody’s branch was most likely too big. It didn’t fall down, it barber-chaired, the back end shot up, the branch snapped and rolled down the bucket arm all the way to the bucket. It crushed Jody in the bucket. He was rushed to hospital but succumbed to his injuries. He leaves a ten year old daughter. I believe there was a fund established to help her pay for future schooling. Contribute if you can.

When you go outside to work remember Jody and stay safe. Municipalities have regular safety meetings; private sector companies are encouraged to conduct regular tail-gate meetings to discuss safety. Sadly, sometimes things go wrong.

 

 

 

Mar 14
0

Tree lessons from a mall parking lot

By | Arborist Insights, Landscaping | No Comments

Visiting your local shopping mall can be a fun green experience. This past weekend I dropped off my son at a gym for a friend’s birthday party and headed to a nearby mall Starbucks. While my wife enjoyed her first latte macchiato, I was more interested in the parking lot trees.

First, the good news.

The newly planted Sorbus aucuparia ‘Rossica’ (Russian mountain ash) is a beautiful specimen tree suited for cooler climates. It has ash-like leaves but actually belongs to the rose family. It’s a pyramidal tree with lobed leaves that turn orangey-red in the fall. In mid-spring white flower clusters emerge; and in winter we get clusters of red berries. The berries attract birds and they always remind me of mountain ashes.

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Sorbus berries

 

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Sorbus aucuparia ‘Rossica’

 

Sorbus aucuparia has year-round appeal and likes full sun which it will get in the middle of a mall parking lot, plus plenty of reflective heat as the pavement heats up.

Now, for the bad news.

Take a closer look at the tree install. The fresh mulch is great for the tree because it keeps moisture in (soil water retention) but why the classic mulch volcano? Dr. Linda Chalker-Scott writes  that piling mulch too high creates a dark, wet, low oxygen environment to which above-ground tissues are not adapted. Fungi love these conditions and are likely to infect the tree; pests can also use the moist conditions to enter the tree bark.

 

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horrific mulch volcano

 

Do not create mulch volcanoes. Instead taper the mulch to almost nothing as you get close to the trunk. This creates a donut  shape which protects the soil environment and above-ground tissues. Remember: donut shape!

Still thinking about mulch volcanoes, I picked up my son at the gym where young cheerleaders ran around in VAS t-shirts. My kind of gym! Vancouver All Stars.

 

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