Posts tagged “yamadori

Potentilla fruticosa

This Potentilla is as fragile as a stained glass window and parts of it literally crumble away every time I work on it. It has undergone some pretty radical changes since I acquired it in 2011, and certainly does not look like the tree I initially envisioned it would become when I bought it. If I could give one piece of advice to anyone who wants to work with Potentilla – especially a deadwood specimen – I would say keep the trunk as clean and dry as possible. They are extremely susceptible to rot. Brush it, lime sulfur it, treat it with wood hardener, remove dead bark… all that good stuff is essential. 

The main things I did this year were to remove the last of the rotting parts, soak every piece of deadwood in lime sulfur then wood hardener, and compact the crown. I also completely redesigned the branch structure such that it is much more simple and “bonsai like”. This is contrary to the wayward, random nature in which Potentilla grow. I’m not saying the current image is better than some of the earlier ones. Certainly some incredible deadwood features have been lost.

Next step is to find the right pot, which certainly won’t be easy. I figure this tree still has a couple years of life before it returns to the dust from whence it came.


The crown still needs a bit of filling out, but that won’t take long.


This is the earliest image I have of the tree. I have no idea of the dates, but presumably the top left shows the tree soon after collection, while the other is the pinnacle of the tree’s development under its previous owner.


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.


Rocky Mountain Juniper Cleanup

This RMJ was collected spring 2012 in the Canadian Rockies. While it has been growing very well, it probably won’t be ready for styling work until next year.

In the meantime, I cleaned the tree up, removing dead bark and highlighting the live vein. Probably the most frustrating task is removing old dead bark that is fused to the deadwood. I have found two tools to be particularly useful for this. Use as sparingly as possible to minimize toolmarks.

After several hours of work, the tree is nice and tidy, and ready for further examination. It has some outstanding features, but some challenges as well (as with all yamadori). One of the main challenges will be how to approach the three “trunks” that emerge. Should drastic measures be taken to hide their awkwardness? Or should they be highlighted as a feature which makes this tree unique?

One problem was identified as I was studying the live vein. When the tree was collected, a relatively large branch (thumb thickness) was cut at the top of the tree. The corresponding live vein (which is lovely and could be a focal point of the design) is weakening. I am expecting the live vein to thin out significantly, but I hope it doesn’t die back completely. It will probably take a few years to know the result.

DSC_0485 2

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


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.


Prep Work on Another Juniper

This is a Rocky Mountain Juniper (Juniperus scorpularum) that was collected in the Kootenay region of the Canadian Rockies back in 2009. Although slender it has nice movement, great deadwood details, and lots of branches.

Aside from maintenance pruning and wiring down some primary branches, this tree has never been worked in detail. Today I cleaned the bark, worked on some deadwood, and cut back quite a bit of growth in preparation for its summer styling. Preparing a tree for styling is almost as important as the styling itself. It has taken three years of cultivation and menial work to produce what is now almost a pre-bonsai. It is a long road from fresh yamadori to having something that is ready for bonsai work.

In terms of styling, this tree still has me scratching my head. The main problem is that the view of the trunk with the best movement and lean does not show the lovely natural shari. I will have to make some compromises when styling this tree… either in deadwood, or trunk movement.

Before work.

After work. My favorite view of the trunk… but the shari is at the back.

Another view showing the shari.

Possible front, although the top half of the tree is leaning strongly to the back.

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.


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.

Sweet Little Thuja

Mother nature has done a nice job on this little cedar. It was collected in April and the shallow, dense root ball allowed it to be planted right into a bonsai pot. The shaggy growth hides much of the details, but this tree has excellent movement and taper. Not only that, it has perfectly placed branches with lots of interior growth. If it grows well this year and next, I would expect this tree to be show ready in fall 2013.

This is probably the front of the tree. The Chuck Iker pot was chosen just because it was the right size, but it is actually a pretty decent match to the tree.

One of my favourite features of this tree is the first branch, Shown here from the back, you can see that it has excellent natural movement and character. Like many old Thuja branches, it has been torn down from the trunk, presumably by heavy snow and ice. The relatively fresh looking wood here makes it look like the tear happened only in the last few years. Although this tear happened in nature, it can be replicated artificially as a bonsai technique to redirect an old upward growing branch.

New Rocky Mountain Juniper

I have a friend who lives in the Canadian Rocky Mountains (British Columbia) who occasionally sells me some of his newly collected trees. This is the third RMJ (Juniperus scorpulum) that he has sent me, and the largest. It is a pretty nice tree with a powerful presence and some nice deadwood. The tree was growing in a rock pocket and the rootball is outstanding, and I think this tree has an excellent chance of survival. Sure, the 3,600 km bus ride might have stressed it out a bit, but I still think the chances are good 🙂 The tree still seems to be dormant, so that helps the situation.

Based on my experience, RMJ grow well in the Toronto area. One issue I have encountered with my RMJ is the alarming and persistent Cedar-Apple Rust (Gymnosporangium)… but more on that later. It should be exploding on one of my trees any day now.

Yamadori Rehabilitation Area

Providing good conditions for newly collected material is always tricky when you don’t have a greenhouse. The goal is to protect from wind and intense sun, but the trees still need some sun to recover (especially spruce and larch). I have my trees up against a fence, and a double layer of shade cloth protecting the southern exposure. As trees gain some strength, I will remove one layer. The strongest trees may be moved into direct sun later in the season. I am also misting them as frequently as possible. It has been very windy the last few days, which is not a good thing.

This year, I also gave my newly collected trees a sprinkling of systemic imidacloprid granules. This is mainly to help the larches fight off any borers they may have brought home with them. I suspect that borers contributed to the decimation of last years crop of collected larch.

Something else new I’ve tried this year with my larch is screwing the tree into the wooden box instead of wiring them in. I got this idea from Sandev Bonsai. It can be very tricky to securely wire yamadori into pots. Since larch usually come out of rocky soil with few feeder roots but a number of thick stubs where large roots were cut, it is much easier to drill in a few brass wood screws to lock them into the box. It is imperative that these trees don’t wobble to protect the fragile roots.

Thuja occidentalis Slab Planting

The other day I planted this Eastern White Cedar (Thuja occidentalis) on a slab I picked up from Aichi-en in Nagoya, Japan. I believe the slab is made of concrete, although the artist did a very good job of giving it a natural form and texture.

I had the help of a friend who has much more experience planting trees on slabs than I do. I was expecting to have to make a retaining wall out of muck like Bjorn does for a white pine in this excellent video, but I learned that this step is completely unnecessary with healthy Thuja because of its incredibly dense root characteristics.

Unfortunately I didn’t get many pictures of the process because I was busy working on the tree 🙂 However, the key points to planting Thuja on a slab are as follows:

  • The material should be well established and have a dense, fibrous rootball. Most Thuja can produce this in two years of growth in a coarse bonsai soil such as a lava rock or pumice based mix.
  • Do not disturb the rootball any more than is necessary. In other words, don’t rake the whole thing out. This will weaken the structure of the rooball and will make it difficult to keep it intact once planted on the shallow stone.
  • Remove thick, downward growing roots.Thuja collected from rocky areas typically have few of these, as was the case with this tree. Once the rootball is shallow enough, leave it alone.
  • Trim long, thick roots that extend beyond the desired perimeter of the rootball. Excessively long fibrous roots can be tucked underneath the rootmass once it is placed on the stone.
  • Tie it in tight. Drill more holes if necessary.
  • Work in soil where necessary, If the rootball is dense and was undisturbed, relatively little soil will need to be worked in near the trunk.

"Before" (this is actually a picture from last summer).

The rootball tied into the stone. I'm guessing only about 25% of the rootmass was removed for this planting.

The result. I am happy with the stone and the more upright planting angle. This is actually closer to how it was growing in the ground. This tree still has a lot of development ahead of it, so there is no point in adding moss. No top pruning was done. The tree just looks thinner because it shed its foliage last fall, after the first picture was taken.

Perlite as a Bonsai Substrate

Perlite is readily available and cheap, but I’ve never really used as a soil component because it is too lightweight (floats/doesn’t weigh down the pot) and it is really ugly.

However, I’ve noticed that there seems to be a practically religious following in Italy of bonsai growers who swear by using pure perlite for rehabilitating recently collected yamadori.

As evidence of the powers of perlite, check out these amazing pictures taken from this thread on the forum, which is administered by Andrea Meriggioli (a young professional in the very serious Italian bonsai scene):

Pinus nigra... once of those "oops" trees that did not exactly come out of the ground as expected. It is amazing that Andrea even bothered to try with this tree.

As far as pine goes, this is practically no roots.

Planted in pure perlite

Here it is budding out. The tree is still alive today!

It even has roots coming out of the pot in the same growing season as it was planted.

I’m not sure if perlite can be given all the credit for this pine pulling through. Andrea also used a number of tonics when he planted the tree (“radimix, bioxim, and antym kombu40 etc.”), whatever that stuff is. Nevertheless, it is an impressive story.

Tired Old Potentilla fruticosa

The potentilla that is the subject of this post was collected about 10 years ago by a friend of mine. I have admired this tree for some time, as potentilla’s of this size and drama are quite rare. When I had the opportunity to buy it for a reasonable price last year, I didn’t hesitate!

Potentilla fruiticosa yamadori


However, this tree has some serious issues and serves to illustrate some limitations of potentilla for bonsai. In a recent post, I said that potentilla are one of my favourite species. They are certainly not perfect, however. Many people will refer to the limited longevity of potentilla. While they are hard to kill, their weedy growth habit is subject to dieback. Their biggest issue, however, is wood rot. This tree is a perfect example of the issues that arise with potentilla over time.

When designing potentilla bonsai as a deadwood species, you must be very conscious of the soft wood. It is nowhere nearly as robust as the deadwood of other deadwood species such as Thuja and Juniperus, and requires extra care. This means treating at least once a year with a penetrating wood hardener, and keeping the deadwood clean and dry. This is the product I like to use.

These techniques were not applied to this potentilla over the last decade, and as a result it has lost much of its structural integrity as a result of rot. Some of the fine jins near the base of the tree also crumbled away when I first laid hands on the tree last summer. The tree is literally falling apart. To make things worse, was planted in a very mucky organic soil mix which takes a long time to dry out.

The purpose of this spring work was mainly to take steps to minimize the advancement of the rot by doing the following:

  • Remove as much of the rotted wood as possible
  • Bareroot the tree and replace the soil with a coarse inorganic mix
  • Plant the tree more upright so that the deadwood is far away from the soil surface
  • Treat with limesulfur, then wood hardener

Crevices such as this are highly at risk of rot, especially if they are not kept clean and dry.

This organic soil mix holds far too much water. This rotted the jins that (used to) lay on the surface and also creates too much humidity for the deadwood that lies above the soil. It is worth noting, however, that the tree grows fine in this soil. Potentilla will grow well in almost anything!

The video clip below shows the extent to which the rot has compromised the structural integrity of the tree.


This is the new pot. It is a yamaaki pot with some signs of age. It is far from ideal, but I think it is a slight improvement on the current pot. I think this tree is ideally suited to a crescent stone, but I have not been able to find the right one yet!

After much struggling, I decided to break the pot. The unusual shape made it very hard to get the tree out and, given how fragile the tree has become, I did not want to pry on it too hard. This pot was made by the previous owner and he warned me that I might have to break it - sorry! :)

Barerooted with the hose and trimmed. You can see that the root system is strong despite the difficulties the tree has presented to the bonsai design.

The tree is so "floppy" that it had to be tied to itself in order to achieve the desired angle. This guy wire is hidden at the back of the tree and can be adjusted if needed.

Thats it for now. Much cleaning and wood preservation still needs to be done, but I think that the deadwood is much safer now than it was before.

The back of the tree is quite interesting as well. As the structure of this tree continues to deteriorate, I am sure that I will have to keep other design possibilities in mind.

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

Grafting Hinoki on Thuja (Arborvitae) Part 1

Many people think that the foliage of Thuja is untameable and unsuitable for bonsai. This is not true – a very refined image can be produced with the native Thuja foliage, especially for medium to large bonsai.

However, there is always the possibility of grafting the more fine hinoki foliage on if you are truly dissatisfied with the native Thuja. The two species are, after all, quite similar. While hinoki has better foliage characteristics, thuja has better vigour and wild specimens have incredible deadwood features. When I showed pictures of my collected Thuja to Junichiro Tanaka (owner of Aichi-en in Nagoya), he described them as “Hinoki Juniper”.

But even though I am content with the native foliage, sometimes grafting is necessary. Take this tree as an example.

When it was collected, I planned on building the bonsai from the branch closer to the trunk. The longer section was to be cut off when the tree recovered.

The long, far away section of foliage had no purpose for the bonsai design.

Why didn’t I cut it off when I collected it? Well, I’m not totally convinced by the “balancing the roots with the shoots” idea. It seems like common sense that leaving more foliage will give the tree more strength to produce new roots, as long as you can minimize transpiration with misting.

Well, it looks like I ate my words here. The most important branch died, of course. I think this is because the roots supporting it were damaged when collecting. Cedars have a very “divided” lifelines that are distinctly attached to roots. If I killed the roots that supported that branch, there was not much hope.


The trunk is nice enough that the tree is worth setting aside as a grafting project. I have never grafted cedar, and this will be an exciting project for this year (and maybe a few years to come). Nick Lenz has a “hinoki cedar” that is rather famous in the Eastern North America. It took him something like 4 years to completely replace the thuja foliage with hinoki. I believe he used thread grafts for this (yes I know… sounds insane) and Chamaecyparis obtusa ‘Nana’ (dwarf hinoki).

An older picture of Nick Lenz's "Hinoki Cedar", created by grafting Dwarf Hinoki onto a collected Thuja occidentalis trunk.

I am not planning on using thread grafts, nor am I planning on using Dwarf Hinoki. I will try two types of graft – approach graft and bud graft using Chamaecyparis obtusa ‘Kosteri’. This variety seems somewhat more vigourous that ‘Nana’. The foliage is not as compact, but it is still very fine, dark green, and somewhat less curly than ‘Nana’. Hopefully the greater vigour of Kosteri will accelerate the grafting process. Check back soon for updates.

'Kosteri' Hinoki foliage.