Posts tagged “Thuja

Bending a Heavy Jin and Initial Styling of a Cascade Thuja

I collected this cedar in 2013 and only this year decided to style it as a full cascade. The big character jin jutting towards the lower left is amazing, but presents a practical challenge for getting the tree into a classic cascade pot. Instead of removing it, I thought it would be interesting to try to bend it flush to the trunk. In addition to solving the pot problem, it would also add some thickness to the base of the trunk, which has some distracting reverse taper.

The cascade style is often a solution for a tree that emerges from the soil with a sharp bend.

The cascade style is often a solution for a tree that emerges from the soil with a sharp bend.

Before bending the jin. This image also better shows the reverse taper of the trunk.

Before bending the jin. This image also better shows the reverse taper of the trunk.

Some of the jin had to be shortened so it could clear the soil surface when bent in.

Some of the jin had to be shortened so it could clear the soil surface when bent in. I hate removing ancient deadwood from collected trees, but sometimes it is necessary to realize the design. 

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The elbow of the jin was notched and some wood removed from the back. It was also wrapped in a wet rag several days before the operation.

Strategic parts of the jin were protected with aluminum foil then steamed with a torch to facilitate the bending. Two clamps were used to crank the jin in.

Strategic parts of the jin were protected with aluminum foil then steamed with a torch to facilitate the bending. Two clamps were used to crank the jin in.

We were amazed that the jin did no even show signs of cracking or tearing. When flush with the trunk, it was secured with two stainless steel screws.

We were amazed that the jin did not show signs of cracking or tearing. When flush with the trunk, it was secured with two stainless steel screws.

A better look at the bend jin.

A better look at the bent jin.

The bent jin from the back.

The bent jin from the back.

After setting the basic structure. The two unnecessary branches will be kept for a year or two until the main foliage mass gains more vigour. Hopefully this will help minimize dieback of the two live veins, both of which are visible from the front.

After setting the basic structure. The two unnecessary branches will be kept for a year or two until the main foliage mass gains more vigour. Hopefully this will help minimize dieback of the two live veins, both of which are visible from the front.

Photoshop without sacrifice branches. The crown will probably be 30% larger in the future.

Photoshop without sacrifice branches. The crown needs to be about 30% larger to better balance out the massive trunk. 

Image from May 2015 repotting. This tree has a surprisingly compact root ball and while it will not be easy to get this into a cascade pot, I think it will be possible without any major operations.

Image from May 2015 repotting. This tree has a surprisingly compact root ball and while it will not be easy to get this into a cascade pot, I think it will be possible without any major operations.


Some Images from the Royal Botanical Gardens Bonsai Show

The Bonsai Society @ RBG put on a show this past weekend that was both well-executed and well-attended. Here are just a few of the many excellent trees that were on display.


Sandblasting Some Large Eastern White Cedars

Prior to last week I had only tried sandblasting on one small cedar. The results were excellent, but I was limited to using my friend’s small parts sandblasting cabinet which could only handle a shohin sized tree. Recently, however, a member of our club got a full sized sandblasting tank and offered to let me try it out on some larger trees. Often sandblasting is done in an enclosed tent or room, but we just did it out on his lawn.

This tree was collected in spring 2013. Last year I did a rough initial cleaning on it using hand tools, but with a craggy old thing like this, sandblasting is the most efficient way to clean away all the old dead bark while preserving the details of the deadwood. Many of the cracks and crevices are impossible to access with hand tools. Sandblasting should be a once-in-a-lifetime event for a tree. Once it is done, the deadwood can be maintained over the years with gentle brushing (water and toothbrush) and lime sulfur application (although this is often unnecessary on thuja as their deadwood will naturally bleach in the sun as long as it is clean).

We used aluminum oxide media at 50-90 psi.

The tree before sandblasting. The trunk was wet at this point as it had been raining, so it is much darker looking than it actually is.

The tree before sandblasting. The trunk was wet at this point as it had been raining, so it is much darker looking than it actually is.

Preparation is important. Covering the soil prevents it from getting blown away. Covering the foliage is absolutely necessary. We chose to cover the live vein with modelling clay as insurance, although this is not strictly necessary if you are careful. The bark is surprisingly resistant to sandblasting. I've seen pictures from Takeo Kawabe's book (Kimura's student) who seems to sandblast junipers with no live vein protection.

Preparation is important. Covering the soil prevents it from getting blown away. Covering the foliage is absolutely necessary – it will die if it is hit by the media. We chose to cover the live vein with modelling clay as insurance, although this is not strictly necessary if you are careful -the bark is surprisingly resistant to sandblasting. I’ve seen pictures from Takeo Kawabe’s book (Kimura’s student) who seems to sandblast junipers with no live vein protection.

After about two hours of sandblasting. 90% of that time was waiting for the tank to repressurize. Sandblasting requires a high CFM compressor and the one we were using was unable to keep up for more than a minute or two.

After about two hours of sandblasting. 90% of that time was spent drinking beer and waiting for the tank to re-pressurize. Sandblasting requires a high CFM compressor and the one we were using was unable to keep up for more than a minute or two.

Unwrapped.

Unwrapped.

Very happy with the results.

The medium we used left a slight texture behind on the deadwood but it is all we had to work with. I am still very happy with the results. The live veins will be further defined over the coming years.

This heavy break will unfortunately be hidden in the back of the tree. It is gorgeous but there are always compromises with yamadori.

This heavy break will unfortunately be hidden in the back of the tree. It is gorgeous but there are always compromises with yamadori.

Another candidate for sandblasting. This tree was probably collected in the 80s and was once a bonsai, but  had been growing as a garden plant for 10-15 years. Most of the branches are unusable and it will be a challenge to bring this one back.

Another candidate for sandblasting. This tree was probably collected in the 80s and was once a bonsai, but had been growing as a garden shrub for 10-15 years. Most of the branches are unusable and it will be a challenge to bring this one back. I’ve been rehabilitating it for two years, but you can only expect so much backbudding from a thuja.

After blasting. No trunk protection was used to sandblast this one.

After blasting. No trunk protection was used to sandblast this one.

You can see where some of the bark was blasted away, but nothing too major.

You can see where some of the bark was blasted away, but nothing too major. I will likely polish the bark on this one anyway.

Original front of the tree 20 years ago. Likely the new back as the deadwood is quite flat and the inverse taper more pronounced.

Original front of the tree 20 or so years ago. It is likely to become the new back as the deadwood is quite flat and the inverse taper more pronounced.

An old picture of the tree.

An old picture of the tree from the Toronto Bonsai Society website.

This tree was also sandblasted then a basic structure was set. Sorry, no before picture. It was collected in the 90s by a senior club member and is very overgrown, therefore it will be a few years before it is presentable.

This tree was also sandblasted then a basic structure was set. Sorry, no before picture. It was collected in the 90s by a senior club member and is also quite overgrown, but not as bad as the previous one. It could be presentable in two years.

 


Detailed Wiring of Big Eastern White Cedar Complete

Previous posts about this tree:

http://lakeshorebonsai.com/?p=2331

http://lakeshorebonsai.com/?p=2172

It is looking very sparse right now due to the removal of old foliage and unnecessary branches, but hopefully it will fill in before the end of this growing season. Its current sparseness gives an opportunity to see the strange relationship between the two trunks. As the foliage fills in, the pads and the spaces between them will become more well defined.

This tree is big, about 65 cm tall from the lip of the pot, and weighs about 100 lbs.

This tree is big, about 65 cm tall from the lip of the pot, and weighs about 75 lbs. The two top jins are of equal height – a problem which I will address the next time I work on the tree.

This is a photoshop adjusted picture showing how I would like to reduce the top jin on the right, and bend the on on the left to emphasize movement to the right.

This is a photoshop adjusted picture showing how I would like to reduce the top jin on the right, and bend the jin on the left so that it better matches the overall movement of the tree.

Rights side

Right side. I’ve always struggled with the flatness of the main trunk, but yamadori always have their faults.

Back

Back

Left side

Left side


First Styling of Small Thuja

This is one of my smallest eastern white cedars, collected in the spring of 2012. It took longer than it should have to reach peak health following collection because quite a bit of mucky field soil remained in the root ball until spring 2014 when it was completely bare rooted. This year it was healthy enough for a rough initial styling. Next year it will be planted in a new pot at the correct angle and the deadwood will be cleaned. It could be show ready by fall 2016.

One year after collection, still in an untouched state.

One year after collection, still in an untouched state.

Healthy and ready for work.

Healthy and ready for work.

After recent work.

After recent work. Growing a new apex is the priority for the rest of this season. This tree has some excellent deadwood which is still obscured under dirt and dead bark. 


Strong Canadian Presence in the 2014 US National Bonsai Exhibition

I recently received my Fourth US National Bonsai Exhibition Commemorative Album and have thoroughly enjoyed studying the over 200 top quality bonsai displays in what is widely agreed upon to be the best US National Exhibition to date. As you probably know, this exhibition and commemorative album is the product of the tireless efforts of William N. Valavanis. As I have come to expect, the album is expertly photographed by Joe Noga and professionally designed and annotated by Bill and his staff. However, what truly makes this year’s album special to me is the strong representation of Canadian bonsai art.

For decades, bonsai enthusiasts from Ontario and Quebec have traveled to Bill’s International Bonsai Arboretum  and other venues in Rochester to receive a world-class bonsai education. For many of us, this education culminated in an invitation to share some of our best bonsai in the 2014 USNBE. Members of the Karamatsu Bonsai Study Group in Montreal have exhibited their stunning bonsai at past US National Exhibitions, but 2014 marked the first time that special exhibits from both Quebec and Ontario bonsai societies were invited, making for a stronger Canadian presence than ever.

I counted fourteen displays from private collections in Ontario and Quebec and almost all of them were collected native specimens. Those who know me know that I firmly believe that our native species, especially Thuja occidentalis and Larix laricina, have the potential to be absolutely world class bonsai, even next to the mind-exploding yamadori of the west coast. It makes me extremely proud to see them well represented in this album and I hope that the Canadian presence at this important exhibition will continue to grow.

Bill was kind enough to allow me to reproduce some of the images from the album here and I have decided to focus on the Canadian trees. To fully appreciate the beauty of this exhibition and see more of the outstanding Canadian trees (not to mention the award-winning American masterpieces), you can easily purchase your own copy from Bill.

 

 


Preparing Displays for Toronto Bonsai Society Show and Sale

Here is one display I will have at the Toronto Bonsai Society Show and Sale this weekend. I hope to see you there!

Collected Thuja occidentalis with moss accent.

Collected Thuja occidentalis with moss accent.

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Thuja occidentalis Foliage Shedding

This is peak season for eastern white cedar foliage shedding. While not at all a health concern, it is somewhat unsightly and can leave your tree looking quite sparse.

To reduce autumn foliage shedding, I’ve been following the advice of Reiner Goebel and making sure I prune my cedars some time around mid-August. This year the results are really showing. Bear in mind that if a tree is early in it’s development or recently collected, it is often better to avoid pruning and just let it shed.

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Pruned August 21st.

Pruned August 15th

Pruned August 15th

Pruned August 20th

Pruned August 20th

Not pruned

Not pruned

Not pruned

Not pruned

Not pruned

Not pruned


Thuja occidentalis progression

This is the first large Eastern White Cedar I collected. After four years of growing, the foliage mass was finally ready for some real work and this year it has gotten a lot of attention. In July it was thinned and roughly wired, and today it received its second and final thinning for the year.

I think this tree is actually two separate trees that have been growing together for a long time. The second trunk on the right is growing towards the back, and I’ve always toyed with the idea of removing it since it seems out of place. David Easterbrook and Marco Invernizzi both advised me not to remove it, and now I am starting to understand why.  That secondary trunk provides much of the depth of the tree and without it I would be left with something very two-dimensional.

It will be difficult to find a traditional bonsai container that works for this tree. I’ve got some ideas for the future planting, but it will not be easy to pull off. The final planting will determine which of the large jins I end up keeping, if any. If I can sort it out next spring, this tree might be ready to be shown in Fall 2015.

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As collected Fall 2010. Note the fist-sized rock lodged in the base of the trunk which had to be cut out with a die grinder.

Late summer 2011 after removing a major foliage mass from the upper left of the tree.

Late summer 2011 after removing a major foliage mass from the upper left of the tree.

Summer 2012, completed barerooted and repotted into a much smaller grow box.

Summer 2012, completely barerooted to remove the toxic muck and repotted into a much smaller grow box.

Summer 2013. Some major pruning and coarse wiring was done this year to open up the foliage and set the basic structure of the secondary branches.

Summer 2013. Some major pruning and coarse wiring was done this year to open up the foliage and set the basic structure of the secondary branches.

July 2014 after thinning and re-wiring.

July 2014 after thinning and re-wiring.

Today after another round of thinning and minor adjustments. There is still a fair amount of floppy foliage but that is gradually being replaced with tighter growth or removed entirely.

Today after another round of thinning and minor adjustments. There is still a fair amount of floppy foliage but that is gradually being replaced with tighter growth or removed entirely.

Future planting angle?

Future planting angle?

 

 


Thuja occidentalis Initial Cleaning

This large Thuja was collected in Spring 2013 and this year has been growing well enough that I have started some basic work. In the first year of collection, I try to do absolutely nothing to a tree – not even move it around the yard. Cleaning work like this invariably involves bumps and vibrations, so I don’t do it until the tree is obviously strong and established in the grow box – typically the second year.

This is not a thorough cleaning – just the removal of bark that come off easily, getting piles of detritus out of cracks and crevices, and cleaning the deadwood with water and a toothbrush to get rid of algae. After this it is easier to study the tree and identify the path of the live veins. As the live veins swell up over the next few years, they will be defined further.

The thin dead bark that is really stubbornly adhered to the deadwood will gradually be picked at over the next few years. Removing it right now would require aggressive scraping or rotary brushes that would ruin the natural texture of the ancient wood. I’m estimating this tree won’t be show ready for around ten years, so there is no point in rushing things. Cycles of wet-dry-freeze-thaw will aid the gentle removal of the bark.

Next spring it will be bare rooted and repotted into a much smaller pot or box. Like most collected Thuja, designing this tree will be a serious challenge. Semi cascade seems like the obvious direction but close examination reveals that there is no easy solution.

Before cleaning, likely front.

Before cleaning, likely front.

Before cleaning, likely back.

Before cleaning, likely back.

Before cleaning.

Before cleaning.

After cleaning, likely front.

After cleaning, likely front.

After cleaning, likely back.

After cleaning, likely back.

The thin layers of dead bark are the hardest to remove. Since there is no rush, I will pick at it bit by bit over the coming years. Cycles of wet-dry-freeze-thaw will aid the gentle removal of the bark.

The thin layers of dead bark are the hardest to remove.


Small Thuja Wired

Collected Spring 2011, about 30 cm to the tip of the dead spire. The deadwood of this tree was sandblasted last year which helped preserve the lovely little jins. The pot is by Shibakatsu.

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Spring 2011, as collected.

Spring 2011, as collected.

 


Devilishly Sinuous Twin-Trunk Thuja

Trunk lines like this are what keep me trekking into the wild each year to scour for nature’s freaks. This tree was collected Spring 2013 and is gaining strength quickly. I am excited to do the initial work this summer.


A Few Images from the Toronto Bonsai Society Show

Despite is being a less-than-stellar year for fall colour, TBS still put on a good show. Unfortunately I didn’t bring the correct lens for the job so I wasn’t able to get far enough back to get most trees in frame. So here is a small sample of some trees that were on display at TBS.

I’m very proud of myself that I didn’t buy anything in the sales area, despite there being some nice trees that got snatched up pretty quickly.

… well I did buy 10 bags of lava rock, but soil doesn’t count 🙂

Very nice chuhin Japanese maple, trained by one of TBS's senior members for years from either a cutting or an air layer.

Very nice chuhin Japanese maple, trained by one of TBS’s senior members for many years from either a cutting or an air layer.

Very interesting pot by (I think) Horst Heinzelreiter. A creative pairing with this tree that I think works extremely well with the fall image.

Great pot by (I think) Horst Heinzelreiter. A creative pairing with this tree that I think works extremely well with the fall image.

It wouldn't be TBS without some Eastern White Cedars.

It wouldn’t be TBS without some Eastern White Cedars.

Shohin English Oak, 12 years from seed.

Shohin English Oak, 12 years from seed.

 

 

 


Bonsai Society at Royal Botanical Gardens Exhibition

My local club, the Bonsai Society at Royal Botanical Gardens, had our first club exhibition this weekend. Bonsai@RBG was founded almost exactly 4 years ago in October 2009, and we were all proud of the exhibition our young club was able to produce.

Approximately 60 tree were displayed, all on stands and most with accompanying accent plants. We had no backdrops for many of the trees and we thought this would be an issue, but were pleasantly surprised with the feeling of openness that it gave the show. It was nice to be able to walk into the room and gaze across the entire exhibit. Of course, backgrounds are always more desirable in a formal display setting, and this is something we will work towards for future shows.

One of the amazing things about our show was how we all pooled our resources to make the best possible displays. Many of our members do not have stands, so we pooled together everything we had and paired the best stand with the tree, regardless of owner. Similarly, members provided accent plants and scrolls to elevate the display. Without this mutual support, the show certainly would not have come together as well as it did.

Enjoy the pics below of some of the trees I was able to photograph. Most are blurry because of the low light, I had to turn down the shutter speed and of course forgot my tripod.

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A panoramic view of the back wall where some of the larger bonsai were displayed alongside some nice antique scrolls. None of us are experts in displaying bonsai with scrolls, but I think it is safe to say that they added to the beauty of the display.


A Big Thuja That Was Collected This Spring

This large Thuja occidentalis was captured in April of this year. All of the pictures except the last one were taken in April soon after collection, when the tree was still in it’s dull winter colour.

The trunk is huge with some dramatic movement. The deadwood also tells some fascinating stories, particularly the massive break in the 8″ diameter middle section. One has to wonder how damage like this could be done without completely uprooting the tree.

This tree certainly doesn’t present any easy design solutions, so it will be a  challenge. Currently these are the best pictures I have of the tree as it is tucked away in the rehab area.

Hard tree to photograph as the base is covered by some branches.

Hard tree to photograph as the base is covered by some branches.

I've been planting all of my larger collected trees in pure perlite for the last couple of years.

I’ve been planting all of my larger collected trees in pure screened perlite for the last couple of years.

 

Before root washing and potting up, giving a glimpse into the massive base. This is a good example of the impenetrable root mass that Thujas are often collected with. Hosing out as much muck as possible greatly simplifies watering the containerized tree.

Before root washing and potting up, giving a glimpse into the base of the tree. This is a good example of the impenetrable root mass that Thujas are often collected with. Very little of it is actually live root. Hosing out as much muck as possible greatly simplifies watering the containerized tree.

Some details:

A more recent picture of the tree. It has been under shade cloth the entire year.

A more recent picture of the tree. It has been under shade cloth the entire year.


Sandblasting Thuja Deadwood

For years sandblasting has been used in some bonsai circles to clean up deadwood. The idea is that it will remove fuzz from carving, smooth “new” sharp edges created from carving, and strip away old dead bark while preserving the natural texture of the wood.I’ve always wanted to try it on Thuja since they have so many intricate little details which are often covered by old caked on dead bark that is extremely difficult to remove. The alternative is that you pick away at the dead bark with your fingernail or a variety of pointy tools, ideally after rain since the bark is soft. Still, it can be very difficult to get everything and not destroy the little details.

My friend has a sandblaster with a small cabinet so I thought this little guy might be my first test subject.

I've already spent lots of time picking and scraping at the dead bark on this one, but there is still a film of stubborn bark here and there, and the tiny jins on the character spire I am finding impossible to clean without breaking.

I’ve already spent lots of time picking and scraping at the dead bark on this one, but there is still a film of stubborn bark here and there, and the tiny jins on the character spire I am finding impossible to clean without breaking.

Sandblasting works best on junipers or “driftwood species” like Thuja which have a defined live vein that has been cleaned of bark. To prepare the plant for blasting, use a tacky clay like Plasticine to cover the live vein from the soil line to as far up the primary branching you can get. Protect the foliage and pot as best you can. I used aluminum foil and shrink wrap. A cloth and shrink wrap would have worked just as well. This step is MUCH easier if the tree has no wire on it (I learned that the hard way).

The sandblasting was done with a standard glass bead abrasive. I found 70 psi to be pretty ideal.

The sandblasting was done with a standard glass bead abrasive. I found 70 psi to be pretty ideal.

I was very impressed with the results. I kind of expected the small jins to be blasted off, but they were left completely intact and clean as a whistle! Some people might be concerned that the natural silver patina of the deadwood has been lost. Well, if you use lime sulfur that shouldn’t matter to you. Furthermore, I find it takes two years in my yard for this silver colouration to return. In bonsai terms that isn’t really long. Is this a technique I will start using more regularly? While I still need to spend some time closely examining the results, it seems very likely.

After sandblasting.

After sandblasting.

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Thuja occidentalis from Seed in Spain

If you were to ask me to make a list of species that I would be willing to try growing from scratch, Thuja occidentalis would be way down at the bottom. While they have a lot of good characteristics, the foliage can be a pain. For that reason we usually only deal with collected Thuja around here.

I follow quite a few Spanish blog because, well… Spaniards are damn good at bonsai! I was amazed when I stumbled across Carthago’s blog to see he is growing some lovely little Thuja’s from seed with impressive results. While I’m not about to run outside and plant a bunch of Thuja seeds, Carthago’s trees definitely made me smile!

All of the pictures below are from http://carthago2009.blogspot.ca/


New Tree: Thuja occidentalis #16

When I saw this tree at the TBS show and sale I was amazed (and somewhat frustrated) that it hadn’t been bought yet. What does it say about the state of bonsai in the GTA when people aren’t fighting over a tree like this, especially when the owner was practically giving it away? I walked away, came back an hour or so later, and the tree was still there. So I had to step up and buy the damned thing 🙂

This tree is awesome material for many reasons. It is collected so it has character. The movement and branch placement is practically textbook perfect for an informal upright. It is planted in the correct position in a good pot and, perhaps most importantly, the previous owner knew exactly how to maintain Thuja foliage, so it had an abundance of fine twigs which could be used to build foliage pads.

In short, all the hard work was already done by the previous owner over the last 7+ years. I just had to put some wire on it and make it look pretty!

The work involved thinning the foliage and simplifying the branching, wiring everything, focusing the movement of the tree to the right, and shortening the apex. The deadwood was also cleaned and bleached.

Before work

Before work

DSC_0425

Final image

 

The back of the tree is awesome. I would like to try to make this the front one day, but it won't be easy. For now I will enjoy the current front.

The back of the tree is awesome. I would like to try to make this the front one day, but it won’t be easy. For now I will enjoy the current front.


Thuja occidentalis #9

This little thuja was put into a nice Shibakatsu pot last week. This is one of my favorite pots and it suits the tree better than I expected. The major work on this tree is now done – both above and below ground. Now it is just a matter of pruning and pinching to develop the foliage pads. As I refine the foliage, I will slowly scrape the dead bark of the old top jin while trying to maintain the detail of the deadwood. This will be a slow process.

May 2013

May 2013

Summer 2012

Summer 2012

 

Spring 2011 as collected.

Spring 2011 as collected.

 


Cool Thuja

Perhaps my favourite thing about old collected Thuja is the little details.

This tree was brought in to display at a local club meeting, and is more or less the same as it was when growing in the wild. Aside from some casual annual cutting and a bit of wire here and there, the owner has never really tried to make a bonsai of this tree. Instead it is just an old Thuja growing in a pot that is appreciated for its wild beauty. I would probably try to take the tree to a more refined state, although I understand the owner being content with the natural beauty of the tree.

While at first glance a rather and straight and boring looking thing, the incredible details tell another story.

The tree is about 1m tall and is in a Sara Raynor pot. It is a gorgeous pot, but slightly too showy for my taste.

Shari detail.

Strange hollow jin. It almost looks like this was drilled out by a bonsai artist, but it is 100% natural.

Jin.

Shari separating from trunk.


Big Thuja Update

This big Thuja was collected in Fall 2010 and had its first serious root work just over a month ago. It is growing very nicely now, and I moved it into full sun the other day.

As soon as possible this tree will need some major thinning to prevent weakening of the interior growth. Probably 50% of the foliage will need to be thinned. However, before that I decided to cut back some useless branches at the top of the secondary trunk.

This tree actually seems to be two trees/trunks growing together. The main deadwood trunk, and an apparently younger but still interesting trunk behind it. They could work together for a final design, but I think I would prefer the simplicity of the main trunk alone. However, I need to be sure that I can kill off/separate the second trunk without harming the living part of the nicer one. And I am still not 100% convinced as I saw some root fusion when I repotted it last month. The entire deadwood trunk only has one live vein.

Here is the tree as collected in October 2010.


Marco Invernizzi Demo @ Toronto Bonsai Society

Marco has been coming to Toronto pretty regularly for a number of years. This year he did a demo on a less-than-stellar collected Thuja, but as usually he was able to come up with something pretty impressive. His discussion focused on preparing material to become bonsai material, with an emphasis on Thuja.

Although the collected Thuja has some nice features (bark, jins), it is pretty far gone with hardly any interior growth.

Bending the straight jin, with some help.

Demonstrating thinning techniques for the difficult to manage Thuja foliage.

The final tree. Many onlookers questioned keeping the entire length of the 45 degree jin, but Marco proposed that it was the definitive characteristic of the tree, which would make it memorable. You can’t argue with that! Sometimes having a tree that annoys people is worth it’s weight in gold :)


Cedar (Thuja) Leafminer Damage

Thuja occidentalis (Arborvitae) is incredibly disease resistant, and there are only a handful of pests that are of any concern to the bonsai grower. One of those pests is the larvae of a tiny moth called the cedar leaf tip miner.

The following excerpt is taken from a University of Guelph Pest Diagnostic Clinic Factsheet on Thuja occidentalis:

Cedar leafminers are tiny moths native to Canada. Damage is caused by the small larvae feeding within the scale-like leaves of cedar. An infestation is usually first noticed in the spring when the tips of some branches begin to bleach and brown. Heavy infestations can cause severe thinning of the foliage.

The article goes on to say that the disease is not a major concern but, for bonsai growers, it can be aesthetically displeasing and can also weaken the tree if left untreated.

The tree below was collected in late April 2011. I suspect that its recovery left its defenses down, and by August the leafminer had established itself.

Cedar Leafminer Damage on a small (25 cm) Thuja occidentalis. The damage is minor, but enough to have affected the recovery of this recently collected tree.

Treatment of leafminer is relatively simple. Prune away the damaged foliage, and keep the tree in full sun to promote the recovery of the plant’s defenses. A light application of a systemic insecticide such as imidacloprid will seal the deal.

As a preventative measure, Reiner Goebel recommends treating Thuja with a systemic in the spring to avoid unexpected infestations of leafminer.

One month later, the tree is sparse, but happy. The tree should be much stronger through 2012, and I doubt the leaf miners will return. It may even be ready for its first wiring by the summer. Had it not been for the leaf miner, the tree probably could have been wired this spring.


Growth Rate of Stressed Thuja occidentalis

This is not a rule, but you can see that Thuja in some stressed conditions (especially drought, poor soil, and crushing ice) grow as little as 2 radial centimeters every 40-50 years. This promotes the development of great bark and deadwood character in small trees. Good junipers cannot be collected in my part of Canada, but Thuja has much of the drama that is so desireable in Juniper bonsai, combined with a unique ruggedness.

The picture of the rings is from where the old top of this tree was cut back after collecting (not a dead tree 🙂 ). This tree was sold last year.

Old Thuja bark