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Arborist Insights

When you have to top natives for size control

By | Arborist Insights, landscape maintenance, Trees | No Comments

I hate topping trees and so does the International Society of Arboriculture (ISA); they even publish pamphlets detailing why the practice of tree topping is bad. This blog post, however, shows two cases where topping was somewhat justified and forced.

It was forced because a) the strata client insisted that it be done and they pay the maintenance fees so all you can do is attempt to educate them and, b) the natives in question threatened to overwhelm the spaces they occupy.

 

Salix discolor

 

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Before height reduction, Salix discolor. Note its landscape use close to woodland in the background.

 

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This is our native willow and it’s technically a shrub. In this setting it’s used as woodland margin shrub. But there is one problem. It reaches 7m heights quickly and the owners don’t want to see it from their upstairs patio, preferring instead to look at the tall native Douglas firs (Pseudotsuga menziesii).

So I went in with an extendable chain saw, pole pruners, a ladder and my best friend, a Japanese hand saw. Remember, most tree work can be done with a good hand saw.

The idea was to bring the willow height down and it went fairly well although I was a bit frustrated with some of my cuts. The willow is very soft and if you fail to finish your cuts briskly then you risk bark peeling below your cut. But considering that this is a native shrub, I expect it to shoot out again after my assault.

 

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After picture.

 

 

Acer macrophyllum

 

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BC native Acer macrophyllum with 5 lobed leaves (3 lobes dominate). The leaves are, well, big!

 

I wasn’t very happy about being sent in to top a maple tree but what do you do when the backyard belongs to the in-coming strata president? One look at his backyard made me wonder if the big leaf maple (Acer macrophyllum) was planted or simply drifted in. If you could look to the right you would see giants of the same species in the woods. There the maples are left alone and they reach the regular 30m tall, 25m spread dimensions.

 

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There is not enough space for this native species which will reach 30m without topping.

 

Here it is clearly not the right tree species so topping it is somewhat justified except, of course, the tree will grow again and I have a feeling I will get to know it intimately as the seasons pile on.

Most of the work was done with a pole pruner with the exception of the biggest leader. That required a saw and some care because there is a planted garden under the tree.

The owner was happy with my work (of course!) but all I was thinking about was how the tree did not belong there.

 

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After topping picture.

 

 

Conclusion

Tree topping is a horrible idea but in some cases it has to get done. Please try to avoid it as much as possible. The big-leaf maple above will grow again which means I will get called in periodically to bring it down. The same is true for the willow which will eventually reach the upper patio sight lines.

 

Installing a 4′ cedar hedge is a breeze

By | Arborist Insights, Landscaping | No Comments

Putting up a quick cedar hedge barrier can be a breeze. I did it last week in between two yards where one side needs to keep a dog in check. The dog is fine, it’s the owner that fails to pick up after it. But this blog post is about planting a quick cedar hedge, not about suspicious dog owners.

Size

Small size is key because a four foot cedar can be easily purchased at your local Home Depot for $18. Anything larger will require a longer trip to a nursery and higher costs. So let’s assume four foot cedars (Thuja occidentalis) are fine.

Now, when you go to your local Home Depot bring your patience with you. It took me forever to order and pay for 13 4′ cedars. The cashier didn’t have the code so she sent a young dude outside to get one. I could have memorized the entire sales flyer in the time it took him to get back.

Outside, another young dude had trouble counting to 13. He loaded up more than I had paid for and then hopped around the back of my truck recounting and off-loading. So of course, I had to recount everything myself.

Planting

The cedars looked a bit dry. It’s always nice if you can soak the pot before planting. For my project I had a T-formation with 6 and 7 cedars. Normally, people dig a hole and then place their tree inside and so on. But when you plant a full line, it’s best to dig up the entire trench. You can then place the trees in and assess. Is your spacing OK and line straight? If not, it’s easy to adjust the plants without any extra digging.

 

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Before.

 

 

When you remove the tree from its pot, don’t be afraid to rough up the root ball. Gently massage the roots with your fingers. If fingers don’t help, use your snips and cut top to bottom to loosen up the roots. It looks a bit rough but trust me, do it.

Once your cedars are set as a new hedge, backfill the trench with the same soil. If you must bring in new fresh soil, only use it to top-dress at the end.

Watering after install is always a good idea and so is removing any tags from the cedars. New baby cedars are thirsty so keep checking on them. They have to get established and high summer temperatures are coming soon. Don’t neglect this step.

Clean-up

Clean-up is also critical. Now that you have a nice new cedar hedge let’s not spoil the show. Collect all plant tags and plastic pots. Recycle everything if possible. Then blow or rake up any excess soil from surrounding lawn or whatever is nearby.

I also used a small rake to even out the soil and to obliterate my boot prints.

 

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After.

 

Conclusion

Planting a new 4 foot cedar hedge can be a breeze. Just follow the steps above and don’t forget to keep watering the plants as temperatures shoot up in spring and summer. Young cedars are very thirsty.

 

 

When installing artificial turf makes sense

By | Arborist Insights, landscape maintenance, Lawn Care | No Comments

Regular readers of this blog will know that I am not a fan of artificial grass. It’s plastic, man-made with petro-chemicals, it heats up and it doesn’t produce oxygen. But there are legitimate cases where desperate people can find salvation in artificial turf.

 

Dog damage

 

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These people have a tiny back lawn frequented by their dog. The daily urine assault left the grass burned and struggling. The owner tried to fix it, over and over and finally got fed up. Since parting with the family pet wasn’t a popular option, they decided to install artificial turf. And it works in this case. Even our lawn maintenance was awkward before the changeover.

 

Clay soils

 

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Some owners are still clinging to their natural grass lawns. The soils are full of clay. You don’t have to dig far to see it.

 

Our West Coast soils have lots of clay in them which means that lawns installed over them drain poorly. The clay forms a nasty layer that doesn’t allow water to percolate down easily. If you want to fight these conditions one recommended procedure involves top dressing these lawns with organic soil. This can over time break up the clay layer. But this would take time and resources.

So what do you do? You stop fighting the conditions and install artificial turf.

You will notice in the picture that some owners are still clinging to their natural grass lawns.

 

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Note the sticky, dense clay chunks.

 

Shade

 

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In summer these backyards are dark as the Fraxinus trees flush out.

 

Shade also affects grass lawns negatively. Grass needs light to thrive and in this case we have four joined sections of backyards that turn dark in summer as the mature ash trees flush out with new growth.

Two years ago I personally pruned whatever branches I could reach on these mature ash trees (Fraxinus). Alas, it had very little effect on the lawns. They were still shady and weak. So the strata council called a tree company to remove the trees. However, the tree company advised them that the municipality was unlikely to issue tree removal permits because the trees were mature and close to houses.

Ok, so now what? One last idea: artificial turf. It looks great in shade and it eliminates the annual fight with expensive grass seed and soil top-dressing. In addition, landscape maintenance workers don’t mind skipping these units because they are difficult to access with push mowers.

This is one case where artificial turf was the last resort.

Conclusion

If you must have lawn, natural grass is better. I personally dislike man-made plastic turf. But there are cases where installing artificial turf makes perfect sense, such as dog damaged lawns, shady lawns and poorly draining lawns sitting on top of clay soils.

 

 

Oak tree versus artificial turf

By | Arborist Insights, Landscaping | No Comments

It pays to join green Facebook groups because once in a while you run into interesting landscaping cases. Like the case of an oak tree versus artificial turf.

While I am not a fan of plastic grass I will show in a future blog that there are some legitimate cases where artificial turf makes sense. More on that later. For now all we need to know is that the artificial turf install was done well. It was done in Europe in an English-speaking country obsessed with royals. See the picture below.

Poor oak

I understand the landscape installer tried to get a tree removal permit but the local authorities wouldn’t have it. So the oak stayed (yes!) but the artificial turf still went all around it.

I’m convinced that trees and artificial turf don’t mix well. Here’s why.

a) Trees rely on surficial roots to obtain water and nutrients and this root network often extends far beyond the drip line. The oak in this example was left with a small square at its base, the rest of the area got artificial turf. This will make it extremely difficult for the tree to obtain all of its required resources.

b) Artificial turf usually involves the use of compactor machines and soil compaction around tree bases is deadly. Once the soil gets compacted it’s difficult for the tree roots to obtain resources. Water will just run off instead of penetrating into the soil. Soil compaction is a silent tree killer.

This install didn’t use any stone crush base and it’s not completely clear if the soil was compacted with a machine. Any landscape work around the tree base is detrimental. The bare soil must have been graded before turf install.

c) Artificial turf heats up! I know this because my son plays soccer. If the turf can heat up my son’s modern plastic cleats, imagine what it does to the soil below. Soils under artificial turf die. My poor son suffered during his match because the host soccer club failed to water the turf. Who will help the poor oak?

 

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Conclusion

It takes time for trees to decline and die. I don’t like this oak tree’s chances. I’m convinced that landscape trees and artificial turf don’t mix well. You can have one or the other but not both.

 

Basic tree maintenance techniques for landscapers: 3-point cut

By | Arborist Insights, landscape maintenance, Trees | No Comments

There are many key landscape maintenance techniques all landscapers should know well. I try to teach these techniques to our new company recruits; and home owners can benefit as well from knowing them. Trees are an important component of our landscapes and must be maintained properly.

 

Three point cuts

This is a basic technique all landscapers must know. ISA certification is not required, although I always recommend it to workers with 2-3 years of field experience. This 3-point cut technique does appear in the Certified Landscape Technician practical testing module on pruning. However, you just have to tell the judge how you would make the 3-point cut because they use one tree to test all candidates.

For now, let’s stick to basics.

Yesterday I was at a site doing normal winter maintenance. I finessed beds, blew leafy piles and then I ran into Magnolia trees that were clearly encroaching on a staircase. So I took action because I had time for it and I also enjoy the work.

To remove an unwanted branch, you must use a 3-point cut, unless you’re removing a smaller branch that could almost be taken off with hand snips. Why 3 point? Because first you have to take off the weight of the branch. If you don’t you risk bark damage.

 

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(1) Undercut (White arrow)

Make a decent undercut without getting your sharp hand saw pinched by the wood.

(2) Second cut (Green arrow) to take the weight off. See how cleanly the branch shears off. If you attempt to make just one cut at the branch collar (Orange arrow) you risk ripping off the bark.

 

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The first two cuts are completed.

 

(3) The final cut happens at the branch collar (Orange arrow). We give the tree a chance to cover up the wound. Just make sure you don’t cut into the branch collar.

 

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The branch collar is clearly visible.

 

 

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All done!

 

The problem with stubs

Leaving a stub means the tree can’t properly heal the wound by closing it over. The stub dies anyway but it could allow diseases to enter the tree. So make proper cuts without leaving stubs.

 

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Acer griseum with a stub.

 

This cut was poorly done. The stub is clearly dead and you can see how the tree tried to cover up the wound. You wouldn’t believe how many of these cuts I see in the field. Sometimes the dead stub just breaks off.

Once you learn the 3-point cut, it will become automatic with practice.

 

Why pollarding trees gives me a rash

By | Arborist Insights, Pruning | No Comments

I’m kidding, of course, I don’t suffer from rashes after tree pruning. But I do find pollarding too forced and ugly immediately after. In summer, when the tree crowns are full of foliage the trees look fine.

Incredibly, I’ve been an ISA certified arborist since 2006 but last week was my first-ever pollarding session. Since our site was all snowy, it was a great time to prune trees.

Why pollarding?

So why do we resort to pollarding? In the very old days, people understood that cutting down all of their trees for firewood was short-sighted. So instead they pollarded their trees and then used the wood. But times have changed.

Now we pollard trees to keep them at a smaller size then they would otherwise reach. It makes sense at our site where three London plane trees (Platanus x acerifolia) are located close to the pool. See the picture below taken from my Kindle e-book: Common Strata Plants: A Guide for West Coast Landscapers, available for download from Amazon.

 

Platanus x acerifolia

Platanus x acerifolia

 

Pollarding involves the removal of the upper branches of a tree which then promotes a dense head of foliage and branches. It just looks like hell right after you do it. In a perfect world, the London plane trees could be let go to grow as big as they wished. I wish!

The trick, then, is to pick a height and pollard the trees annually. The actual work is very simple because you’re simply beheading skinny branches that shot up from the previous pruning cuts. Staying safe while you prune is more demanding.

My arborist technician apprentice climbed the tree while I stayed on the ground and used a ladder with pole pruners. Once in a while I would steal a big-brother glance at my eager apprentice to make sure his ropes were still supporting him.

 

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My work in progress. The gnarly ends of the branches don’t exactly inspire me.

 

Timing

Late winter or early spring are best for pollarding. One exception are maple (Acer species) which bleed sap when cut at these times. The pruning rule for maples is before Christmas.

If you have trees that are outgrowing their space and you don’t want to lose them or can’t afford to replace them, then by all means pollard your trees annually. The trees look horrific immediately after pruning but in summer they’re fine. Personally, I would prefer not to pollard anything.

 

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The case of struggling paperbark maples

By | Arborist Insights, Trees | No Comments

I got to see a number of our sites before Christmas because the regular foremen were on vacation. It’s always nice to get a fresh pair of eyes on site, especially before the holidays. Everything must look perfect for the holidays.

One site in White Rock stood out because of its many paperbark maple trees (Acer griseum). They look awesome thanks to their peeling cinnamon coloured bark. So I was stunned when one of my helpers started rubbing off the peeling bark as if the tree was diseased. He clearly preferred a smooth bark look but I doubt the tree appreciated the assault. I told him to stop.

Every paperbark maple on site looked great until I turned the corner into a dead end surrounded by cement walls on three sides. Here we had two specimens of the same maple species and they were clearly struggling. Why?

 

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A) Lack of light. Trees require sunlight for food production and the setting here is horrific. Since there are cement walls on three sides, this is a shady corner. It’s not a great place for these maples to thrive. And the same goes for the grass. It, too, could benefit from more light.

 

B) Competition. We already know that young trees planted into turf struggle with competition for resources. And they often lose. If you must plant trees into turf areas then establishing tree wells around them to help them. The tree wells channel water and nutrients into the root zone and they keep machines away.

 

C) Conflicts with machines. If you zoom in, you will notice bark damage at ground level. I say it’s line edger damage. The kind of damage that could be prevented with plastic tree guards or by establishing a tree well around the tree.

Repeated hits can kill the tree. Here it looks like the trees are using precious resources for repair and stress mitigation instead of growth. Thus the struggling look exhibited by these two specimens.

One other possibility is digging up the trees and moving them to a sunnier location away from lawns. The cement walls could be covered by climbing hydrangeas which are already planted on this site.

 

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January 2018: sporting a new tree well.

How to pimp out your boulevard tree wells

By | Arborist Insights, landscape maintenance, Strata Maintenance, Trees | No Comments

Sometimes you look out on the boulevard at your strata site and the tree wells look a bit tired. But it doesn’t have to be that way. With some tools and a bit of soil amender you can quickly pimp out your tree wells and make them look great before the holiday season hits.

 

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This looks a bit tired.

 

Step 1

First we grab a nice sharp spade and we deep edge the tree wells. The spade must hit the edge at a ninety degree angle. Nothing else will do.

As for the depth, it should be deep enough to anchor the new soil that’s coming in but not too deep. We’re not building ditches although I have created some ankle-busters in my past. Soil conditions will sometime dictate the appropriate depth.

 

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Acer griseum tree well. You might as well remove the tree guard.

 

Step 2

I know, most people dread this step but we have to weed the tree wells nicely. Use a good cultivator and when you remove the weeds also grab the chunks from step 1.

 

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Nice and clean. The ground was a bit frozen so weeding was a challenge.

 

Step 3

Next, install good quality soil amender and pile it on nicely. Remember, it will settle so don’t worry if the tree wells look a bit puffy. This step gives you an instant upgrade because the fresh black soil looks great!

Warning: do you remember what a doughnut looks like? That is exactly what the soil around your tree should look like. Find the root flare and make the new soil level with it. Then build it up and taper it off as you hit your new deep edge.

Why? Because piling soil above the root flare leads to problems. For some reason, people love building soil pyramids at the base of trees. But it’s a common mistake. The bark above the root flare isn’t supposed to be in a dark, damp environment and it can over time rot. This in turn invites disease in.

Another potential problem is adventitious roots developing above the root flare inside your soil pyramid. There the roots start to circle and they can over time girdle the tree.

So remember, don’t create soil pyramids. Think doughnuts!

 

Step 4

The last step involves clean-up. Especially the grass edges of your new tree wells. Blow them off gently.

That’s it. Now your clients can enjoy beautiful boulevard tree wells on their Christmas holiday walks.

 

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All done! Weeded, edged and top-dressed. This is my kind of tree well.

Bronze birch borer related pruning

By | Arborist Insights, Trees | No Comments

Because I am ISA certified, tree-related tasks are automatically given to me by default. And that’s fine. This blog post is about a birch tree which exhibited top dieback. So I was sent in with pole pruners and an extendable Stihl chainsaw to take care of the request.

 

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It’s not super clear but the top leader is dead.

 

Once I took out all of the dead branches, I pruned the live parts of the tree to give it some sort of shape. Then I hauled out the debris up to the road for later truck pick up. Only later did I realize that my boss expected me to take the whole tree down! Not my style anyway.

Since we suspected the cause of the dieback to be the bronze birch borer (Agrilus anxius) my approach was correct. Pruning out affected limbs is the way to do it. I just couldn’t burn the diseased branches on a strata site surrounded by woods. My only hope is that no adults emerged before the debris was processed with other green waste.

Bronze birch borer

Adult bronze birch borers are half an inch long and have slender dark green bodies with metallic bronze sheen. In summer, females lay their eggs in bark crevices of weak and stressed birches. They prefer sunny, south facing branches.

Larvae hatch 14 days later, enter the bark and feed on sapwood. After one or two years adults emerge by chewing D-shaped holes in the bark.

Signs

So let’s review. Bronze birch borers cause treetop dieback, leaf wilting on branches and D-shaped exit holes in the bark

What can we do?

Since the bronze birch borer only picks on weak and stressed birches we should keep our birches in good shape with regular watering, feeding and pruning. Also, put your birches in shadier corners.

One other idea is to plant birch borer resistant river birch (Betula nigra) cultivars.

If you are lucky, you will get some help from natural allies like parasitic non-stinging wasps and woodpeckers.

The birch featured in this blog post is still alive and standing.

 

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After removing all dead branches and pruning others to give the tree some sort of natural shape.

 

Source: GardenMaking magazine no.30, pp.56 and 58.

When trees and artificial turf are incompatible

By | Arborist Insights, landscape maintenance, Landscaping, Lawn Care | No Comments

My friend who specializes in artificial turf installs told me recently that he was killing it. Great. I was happy for him. He went through his apprenticeship by installing NFL turf and deserves his success.

However, there are some cases where installing artificial turf is a bad idea. Take for example the case below from the United States.

 

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Picture used with permission.

 

Unhappy owner

The owner was unhappy with his lawn and approached his landscape company about replacing it with artificial turf. His landscaper was worried-correctly!-about removing four inches of turf and not adversely affecting the tree. Then she posted this picture in a Facebook group and asked people for their opinions.

Incidentally, I recommend joining a few Facebook lawn care groups. Many of the groups have thousands of members and interesting things pop us almost daily.

Let’s see

This is an interesting case so let’s see.

A) I presume that the tree shades out the grass when it pushes leaves out. You could prune the tree to allow for more light penetration. Another possibility is top-dressing with a light layer of soil and over-seeding with shade grass mix. Baby the lawn a little bit. Aerate it and fertilize it.

B) To install artificial turf you have to remove the top four inches of soil and install rock. You can read my blog about my friend’s project which shows the steps involved in installing artificial turf.

Since trees rely on surficial roots for water and nutrient collection this step would no doubt affect the tree. I also notice large roots that would make it impossible to install the turf perfectly flat.

And to prepare the rock for turf install, it gets compacted with a machine. We know soil compaction kills trees by limiting air and water uptake by surficial roots. Installing four inches of rock and compacting it all around the tree would have serious consequences for the tree.

C) I understand that most artificial turf models allow water to penetrate but I still think it wouldn’t be the same deal for the tree. Then there is the issue of heat. Natural grass produces oxygen and cools down our properties and cities. It’s the opposite with artificial turf. Once it’s installed it heats up and the soil underneath dies. I think the turf would simply “cook” the tree roots.

D) I believe the tree has to go before artificial turf can be installed. Imagine the full effect from grass cooling and tree shade to open artificial turf which absorbs heat and zero shade. Remember, artificial soccer fields should be watered down to protect the players on hot summer days.

E) Then there is the issue of cost. Artificial turf isn’t cheap but it’s easier to maintain than natural grass. I personally dislike anything artificial in my landscapes. Anything that kills soil is bad in my books.

Conclusion

The owners of this property have to find another solution to their grass problems. Artificial turf install is totally incompatible with the tree in their front yard. They can prune the tree and baby the grass. Or they can remove the tree to make way for artificial turf. Of course, this step loses the many ecosystem services provided free of charge by the tree and leads to soil death. I would personally avoid this second idea at all costs.