Techniques

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.


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.

 


Larch Thread Grafting Woes

Most of the old crusty larches I collect need grafting. It seems the older they are, the farther the living foliage is from the interesting part of the trunk. Three thread grafts were started on this larch in spring 2014 and all three of them failed this summer (despite not yet being separated from the donor branch).

Three dead grafts. The middle one was the most important as that was to become the new leader of the tree. The one above that... well it was too high i.e. a mistake.

Three dead grafts. The middle one was the most important as that was to become the new leader of the tree. The one above that… well it was too high i.e. a mistake.

 

I’m not sure why they failed, but I think it might have had something to do with long period of time elapsed. Ideally, once started, a thread graft will grow rapidly and then take within a few months. Unfortunately, these grafts hardly elongated last year therefore they had no change of reaching the thickness required for fusion until they really started to take off this year. But in July of this year when they should have been fusing, they were instead girdled and died. This is purely anecdotal, but I believe that the callus that formed around the edges of the drilled hole was somehow too hardened-off or otherwise too old to readily form a graft union with the threaded branches by the time they were thick enough to do so. Or maybe the drilled hole didn’t form a callus at all.

Anyway, they failed and I needed to re-graft. Late summer is not a good time for thread grafting larch, so I tried a traditional approach graft instead.

I'm not sure what these nails are really meant for, but in Japan they are commonly used for grafting. Here they are not going through the branch, but are just adjacent to it. With thicker branches it is OK to hammer them right through the branch.

I’m not sure what these nails are really designed for, but in Japan they are commonly used for grafting. With this graft they are not going through the branch, but are just adjacent to it. With thicker branches it is OK to hammer them right through the branch. They do an outstanding job of creating a very snug graft junction.

And now we wait...

And now we wait…


Japanese Maple Root Arrangement

Way back in 2011 I remember seeing this Bonsai Tonight post of a Boon Manikitivipart workshop where a participant tried out a root arranging technique of the deciduous bonsai genius Ebihara. What a great idea, right?

Last summer I acquired a maple that turned out to be perfect to try this technique on. It already had several years of root training therefore a good number of flexible lateral roots were present. Still, a fair amount of prep work was needed. The base of the rootball needed to be completely flat and all unnecessary roots removed. Hopefully this will improve the nebari as I rebuild the branch structure of this tree over the next several years.

As a side note, Boon posted an update about the tree in the Bonsai Tonight post on Facebook. Apparently using plywood was a mistake as it rotted quickly. Keeping that in mind, I used pine.

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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 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.


Defoliation of American Hornbeam Forest

This Carpinus caroliniana forest was made in the Spring of 2013 and this year it was defoliated for the first time. Owen Reich told me that American Hornbeam respond well to defoliation (maximum once per year) and indeed the results were positive. One issue I noticed is that as the second flush was coming in, some very vigorous leaves grew back at an accelerated pace and became very large. These were periodically removed to allow the smaller, less vigorous leaves to fill in at a more uniform pace.

The tree was defoliated May 31st, just after the new growth had hardened off. One month later, the second flush had filled in and hardened off.

May 20th, ten days before defoliation. I forgot to take a picture right before defoliating the tree.

May 20th, ten days before defoliation (I forgot to take a picture right before defoliating the tree). The leaves here are not quite hardened off. 

May 31st immediately following defoliation.

May 31st immediately following defoliation.

 

The tree today, just over one month after defoliation. One major effect of defoliation is that the smaller interior shoots were allowed to open up. Many did not open up at all in the spring.

The tree today, just over one month after defoliation. One major effect of defoliation was that the smaller interior shoots were allowed to open up. Many did not open up at all in the spring as all of the vigour went to the shoots of the exterior canopy. After defoliation, the density of the tree is much more uniform. 

 

The new leaves are about 50% the size of the old ones. Very nice!

The new leaves are about 50% the size of the old ones. Very nice!


Canadian Hemlock aka Eastern Hemlock, Tsuga canadensis as Bonsai

This is the first tree I ever collected, over eight years ago now. The development of this tree has been one step forward, two steps back. There is limited information out there on T. canadensis and I’ve only seen two that could be called bonsai (this tree  isn’t one of them). This is probably for two reasons: 1) it is hard to find worthy material, and 2) they are a quirky species to work with.

Eastern Hemlock are unique for a number of reasons:

  • They very, very much prefer a rich and moist organic growing medium. I almost killed mine by transplanting it into a coarse, inorganic medium. Replacing it with topsoil restored the health of the tree.
  • They can tolerate practically any light condition from full shade to full sun. For bonsai development, several hours of direct morning sun is good for promoting backbudding and branch development. Full direct sun tends to cause the foliage to lose it’s rich green colour.
  • Despite their delicate and almost “weak” appearance, they heal over wounds better than any conifer I can think of and better than many deciduous trees. This makes grafting easy on T. canadensis.
  • The branches are very flexible however they are extremely weak at the crotches. They will suddenly and heart-breakingly tear from the trunk with little notice during heavy (or even moderate) bending operations. However, their capacity to rapidly callus over wounds means that a branch will more often than not survive, even if you have torn half of the base away from the trunk.

I have learned and re-learned these points “the hard way” on this poor specimen over the years. The resulting setbacks have probably doubled the time it should have taken me to get to the current stage of development. Now this tree has immense sentimental value to me despite being one of the last trees that draws the attention of any visitors to my yard.

I believe Eastern Hemlock is by far the most delicate and feminine species native to eastern North America, and perhaps even all of North America. This makes it priceless in our catalogue of native species and worthy of greater attention. I just wish material was easier to come across!

My T, candensis today after finally getting the main structure set into place after eight long years.

My T. canadensis today after finally getting the main structure set into place after eight long years. Still a long way to go but I think the hard work is done. 

Last summer I was trying to fully style the tree and had to stop at this point after I tore a major limb that supported two major branches - the first branch on the left, and the back branch,

Last summer I was trying to fully style the tree and had to stop at this point after I tore a major limb that supported two major branches – the first branch on the left, and the back branch.

The tear in the limb last summer. Remarkably, the more important branch (second primary branch) survived despite losing much of the secondary growth. The back branch completely died

The tear in the limb during last summer’s work. Remarkably, the more important branch (second primary branch) survived despite losing much of the secondary growth. The back branch completely died

Growing near a trail in April 2007.

Growing near a trail in April 2007.

Collected and potted up showing the current front.

Collected and potted up showing the current front.

Fall is for Pine Work

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Japanese Black Pine after needle plucking.

I love pines but only have two, one of them being the Japanese Black Pine pictured above. Being a relatively new addition to my collection, I touched its foliage for the first time last week, plucking the needles down to about a dozen pairs over the majority of the tree, with some more aggressive plucking near the apex.

Some bud selection/thinning was done as well – but not too much. I want the weak inner buds to gain strength in preparation for the hard cutback this tree will be getting in a year or two as a step towards my ultimate goal to make it a shohin. If you want weak inner buds to strengthen, it is best to keep some strong foliage on the ends of the branches to keep sap flowing heavily through the branch. Cutting back all the outer foliage as soon as inner buds appear is counter productive. This comes from my friend who is a student of Boon Manakitivipart.

In keeping with the season, below are some outstanding videos of Ryan Neil talking about pines. If you haven’t seen them yet, they are really worth a watch. The first is a shorter “crash course” while the second is a more in depth two part video.

Ryan Neil “Crash Course” on Japanese Pines

Ryan Neil on Pines (Detailed) Part 1

 

Ryan Neil on Pines (Detailed) Part 2

 


Grafting Hinoki on Thuja: Round 3

In Spring 2012, I tried bud grafting hinoki foliage on a scraggly collected Thuja, which failed. Later that year, I tried approach grafting hinoki foliage onto the same plant. Over one year later, the results are still unclear. The approach graft is alive and well, but it has not clearly fused with the Thuja tissue. I have a feeling the wounds on scion/stock both just healed over instead of grafting with one another. At this point I would say the approach graft was not successful.

Not convinced that this approach graft has taken.

Not convinced that this approach graft has taken.

Nevertheless, I left the approach graft in place and moved on with my third attempt of grafting this plant with a third type of graft: the One-Point aka Single-Point Graft.

One-point grafts are very similar to thread grafts, except defoliation is not required. This makes this type of graft a very useful tool for conifers. Many years ago, I successfully one-point grafted my Canadian Hemlock (Tsuga canadensis) after learning about this type of graft from Nick Lenz’s Bonsai from the Wild 2nd Ed. In fact, Nick hints at one-point grafts as being appropriate for Hinoki-Thuja operations, but first describes them in his larch chapter:

A variant of [thread grafting] is the one point graft. Instead of passing a bald branch through a hole in the trunk, you fold over a branch and squeeze it into the hole. Before insertion, you scrape the outer edge of the fold with a thumb nail to remove the cambium. When jammed into the hole, the cambium layers of the drill-out and of the scraping will touch and merge quickly. This approach has several advantages. You can perform it at any time during the growing season as the branch does not need to be bald. This is especially useful in species that grow out but once in a season, such as pines. It also takes less time to complete. You do not have to drill all the way through the trunk, but only a centimeter or less.

The disadvantage to this approach is not great. The branch may be fatally injured when folded over. If this happens and the new graft begins to dry and brown up, you can readily pull it out and try again with a smaller branch. Despite the tendency of a branch to break (crack) when doubled over, you can always find one that will tolerate the procedure. Success is more likely on hot, dry days when water is withdrawn from the wood. -Bonsai from the Wild 2nd Ed., p. 33

A few weeks ago in mid August I looked disgustingly at my still-ungrafted Thuja and grabbed my drill. Three one-point grafts were initiated and today they all still seem to be alive. Basically what I have now are three thread grafts in my Thuja, and hopefully now it is just a waiting game.

A one-point graft that seems to have survived the initial folding-and-cramming.

A one-point graft that seems to have survived the initial folding-and-cramming. The scion for this graft was growing off the scion used for last year’s approach graft.

Another one closer to the base of the trunk.

Another one closer to the base of the trunk. All of the one points were slathered with some Japanese wound sealant which is pretty much white glue.

I'm not sure if this tree is even worth all the trouble. Sure, it will be nice if I can make it a bonsai, but this grafting project now seems more about me proving to myself that it can be done.

I’m not sure if this tree is even worth all the trouble. Sure, it will be nice if I can make it a bonsai, but this grafting project now seems more about me proving to myself that it can actually be done.

 


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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It’s Time to Prune Your Eastern White Cedars

Rather than try and tell you how it is, I will instead quote Toronto bonsai veteran Reiner Goebel, who has several decades more experience with Thuja occidentalis than I do.

“As all trees, cedars shed old foliage in fall. Some time in September, part of the foliage, usually in the interior of the tree, will turn rusty brown and slowly fall off. If you’re not sure whether your tree is shedding or dying, pulling at the brown foliage is a reliable test, because the foliage about to be shed comes off easily, while the foliage about to die requires a lot of force to come off. I believe to have noticed that this natural shedding can be reduced by timing one of the heavy pruning sessions to occur around the middle of August.” -from Reiner’s article about Eastern White Cedar at RGBonsai.com

One of my bonsai teachers also puts it well: “Decide which foliage the cedar will lose, or it will decide for you”.

As Reiner says, it is usually the older interior foliage which is shed – yet this is probably the foliage you want to keep. So pruning generally involves shortening the strong fronds at the tips of branches and those strong ones jutting off the sides. Strong “runner shoots” that often appear sticking straight up at the crotches of branches should also be removed.

This is especially important on collected cedars that are early in their training, since interior foliage is usually sparse and weak (if it exists at all). Late summer cutting helps the tree hang on to that stuff so it has a better chance of gaining interior strength the next year.

This tree serves as an example, a small Thuja collected in Spring 2012. It has been slow to find its legs and is still not at full throttle, but this pruning is necessary to maintain the precious interior growth. Last year it was not pruned at all. Only Thuja that show exceptional growth following spring collection should be summer pruned during their first year of captivity.

Before pruning:

 

After pruning:

In the first few years post-collection, August pruning may be the only cutting that a Thuja will get, while the rest of the year is spent developing a foliage mass. Healthy cedars, like junipers, grow all year and require several pruning sessions.


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.

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Toronto Bonsai Society Show/Sale + Larch Needle Plucking

The Toronto Bonsai Society Spring Show and Sale is being held June 15 & 16 at Toronto Botanical Gardens in the Garden Hall. This event has been happening for decades and is surely the largest and most consistent annual exhibition of bonsai in the GTA. The sales tables are a great place to pick up pots, bonsai, pre-bonsai, tools, and books. I’ve bought several trees from TBS shows/sales, including the one below which I am currently prepping for the show.

With their vigorous summer growth, larch develop needles in all sizes and all directions, and the same goes for shoots (although less-so with mature larches). Two simple things can be done to minimize the wayward bushiness of a summer larch – reducing spring fertilization, and needle plucking. Reducing fertilization is pretty self explanatory – if you are trying to “bonsai” your larch (instead of develop the branches/trunk) don’t fertilize it until the spring growth hardens off.

Needle plucking is self explanatory as well – try to make your larch look like a Japanese white pine. This involves plucking (by hand) all downward growing needles to clearly define the underside of the foliage pads. Downward growing buds/shoots should be cut with scissors. Excess horizontal needles can also be plucked, although be careful not to remove all the needles from a growing center. Also, needles that are growing along the branches in between buds should be plucked, although these are usually only an issue on young (1-2 year old) branches.

Branch before plucking

Branch before plucking

After plucking downward needles

After plucking downward needles

Summer wire application on larches should be minimal unless you are something of a masochist (larch are best wired in spring as the buds start to colour up). However when prepping a tree for show there is nothing wrong with wiring  the odd branch, again with the goal of defining the underside of the foliage pads.

    Branch looking a little droopy.

Branch looking a little droopy.

After minor adjustment with wire.

After minor adjustment with wire.

After work

After work

 


Pinching Japanese Yew

Yew are pinched in the spring to balance the energy of the tree. If they are not pinched, the outer growth will become coarse and the inner growth weaker. Pinching helps maintain or develop finer branching. Yews are not pinched to promote backbudding – they don’t need any encouragement to do that (if anything, they produce too many buds).

Whole-tree pinching as shown here should not be done on trees in development! It is counterproductive to weaken the tree when you are trying to build a foliage mass and grow out branches. I’ve been developing this tree from nursery stock since 2006 and this is the first time I have pinched the whole tree.The last six or so years have been spent developing the roots and basic branch structure.

This is also the first year in which I have held back on heavy spring fertilization – I just gave a little bit of mild organic (chicken manure) to help it bounce back from the pinching. I am not planning on fertilizing it again until late summer/early fall, once everything has hardened off. Too much fertilizer will make the second flush too vigorous. Bud selection and wiring will also happen in late summer/fall.

    The lovely colour of spring yew shoots are just as stunning as some flowering trees, in my opinion. But they've gotta go!

The lovely colour of spring yew shoots are just as stunning as some flowering trees, in my opinion. But they’ve gotta go!

    After pinching. Everything was pinched - even the tiny little buds that barely opened. I left a few basal needles of the pinched shoots, as per Ryan Neil's advice in a youtube video.

After pinching. Everything was pinched – even the tiny little buds that barely opened. I left a few basal needles of the pinched shoots, as per Ryan Neil’s advice in a youtube video.

This tree does still need some branch development, but nothing major. It is often helpful to look at a tree from above to see design weaknesses. Most trees should have a pretty rounded crown when viewed from above. This tree has some noticeable gaps, but they should fill in pretty soon.

Gaps from above show the immaturity of the crown.

Gaps from above show the immaturity of the crown.


Overwintering Bonsai in the Toronto Area USDA Zone 5-6

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I’ve received quite a few emails from people asking about overwintering hardy trees outdoors. While there is lots of good information out there on the internet, most of it is region specific. What applies in England, Japan, or North Carolina does not apply in Toronto. With that in mind, this information is specific to zone 5-6 and is for people who have no special facilities (heated garage, polyhouses, etc.).

Reiner Goebel of rgbonsai.com has a good article about overwintering trees in the Toronto area. Have a read here. What I do is very similar.

  • Use tough species to make life simple. Semi-hardy species (Trident maples etc.) require more attentive care in this climate. My collection consists of Eastern White Cedar, Larch, Juniper, Yew, Siberian Elm, Potentilla, Ginkgo, and  few others. All fully hardy.
  • Don’t be afraid to leave them on the bench through a few late autumn frosts. They can take it. I usually put mine away in late October or early November. If the ground is frozen, you’ve waited too long 🙂
  • Bury the pots in the ground in your garden and water everything really well. This insulates the roots. The risk is not the rootball freezing. It can and should freeze solid. The tree will be fine. The risk is frequent freeze-thaw cycles. This is why unusually warm winters are more of a concern to us northern bonsai growers than unusually cold ones. Burying the pot helps ensure that once the rootball freezes, it will stay frozen until around March, even if there are some freakishly warm days in January (it happens). If your tree is in a massive training box but is a hardy species, just sit it on the ground and mulch around it. Just having contact with the ground will help buffer the rootball temperatures.
  • Snow is your friend. As soon as fluffy snow hits the ground, shovel it onto your trees (don’t shovel on heavy wet snow!). Sure, three feet of snow can bend branches but I feel most comfortable when my trees are buried in snow all winter. This protects from -20 degree air temperatures and drying winds. But when the snow starts to melt, brush it away as this heavy slushy mess can really cause damage to branches and fine ramification.
  • Try and winter them in a shady spot in the garden protected from the wind (i.e. a north facing corner). This provides a bit of insurance against wind and sun if it is a snow-less winter (like the infamous winter of 2011). It also helps keep the tree dormant as far into the spring as possible. This is important. If your trees break dormancy too early, the tender new growth will be exposed to the unpredictable early spring weather.
  • Rabbit-proof your garden as best as possible. When rabbits get hungry in the winter, bonsai bark apparently looks quite appetizing. Even  a couple of exploratory nibbles can ruin the image of a tree. Try to board up any gaps under the fence.
  • If you have the energy, fence in your trees with hardware cloth to provide further protection from pests. Burying the fence a couple of inches provides me some reassurance against mice, although if mice want to get anywhere bad enough, they will find a way.
  • Don’t worry about watering! If you put them away late enough, they should not need any water the entire winter.
  • Again, keep them dormant as long as possible. Don’t take them out of the ground at the first sign of spring in March. You know that in our part of the world it is not impossible to have freezing nights in May, and these spring freezes can kill off tender new deciduous growth.

This approach has worked well for me for 8 seasons. There are many ways to do it, but I find this to be the simplest and most foolproof approach. It takes some time to prep the trees for winter, but once they are in the ground you can literally forget about them, sit back, and wait for repotting season to come! Unfortunately, since the trees are frozen solid in the ground, you cannot really work on them in the heart of winter.


Thuja Grafting Round 2

Well, my attempt at bud grafting hinoki on this Thuja in the spring failed quite miserably. Of the three scions I grafted, only one actually started to push new green tips, but it soon fried once the heat of the summer arrived.

Here is my attempt to use an approach graft. Approach grafting on junipers is often done in the summer. I know this is not a juniper, but I think that Thuja and junipers have a lot in common in terms of their physiology. I have no evidence to back that up except for watching them grow in my garden over the years. I think the summer is a good time for grafting because this is the time when the trees are really throwing out new wood/callus tissue and wounds close up quickly. Also, sap flow is very high. I’ve done some thread grafting on deciduous trees in the summer with good success. I wouldn’t try any sort of bud grafting in the summer as the scion would probably get fried really quickly.

Here is the poor bastard, nice and healthy but dying for some foliage closer to the trunk.

Here is the poor bastard, nice and healthy but dying for some foliage closer to the trunk.\

The first step was carving a channel using a dremel set at low speed with a sharp cutting bit. I did my best to make the channel the same diameter as the scion, and the depth was about half that. The wound was cleaned up with a grafting knife.

The first step was carving a channel using a dremel set at low speed with a sharp cutting bit. I did my best to make the channel the same diameter as the scion, and the depth was about half that. The wound was cleaned up with a grafting knife.

Here is the plant that I am trying to graft to the Thuja: Chamaecyparis obtusa ‘Kosteri’. A really lovely variety and somewhat stronger than ‘nana’.

The next step was securing the hinoki and Thuja containers together. In this case I simply rested the hinoki pot on top of the Thuja and tied the two together with three strong guy wires until they were rock solid. It is very important that they are securely mated so they can be moved around together through the seasons. Even in the best case scenario it could be a year or more before the two are separated. It would have been easier if I had hinoki cuttings in small pots, but this is the only material I have to work with. Making a bunch of cuttings of this variety for future grafting attempts is on my list of things to do.

The next step was securing the hinoki and Thuja containers together. In this case I simply rested the hinoki pot on top of the Thuja and tied the two together with three strong guy wires until they were rock solid. It is very important that they are securely mated so they can be moved around together through the seasons. Even in the best case scenario it could be a year or more before the two are separated. It would have been easier if I had hinoki cuttings in small pots, but this is the only material I have to work with. Making a bunch of cuttings of this variety for future grafting attempts is on my list of things to do.

Here is the branch to be grafted with the bark scraped off to expose the green cambium. It is probably a 2 year old branch. Before scraping, make sure you do a test fit to make sure you are scraping in the right place!

Here is the branch to be grafted with the bark scraped off to expose the green cambium. It is probably a 2 year old branch. Before scraping, make sure you do a test fit to make sure you are scraping in the right place!

I fit the scion into the channel and secured it in place with two wires with some protective rubber. It must be very tight. Try pushing on the scion - if it still flexes into the channel, it is not making good contact and must be tightened. The whole thing was then covered in grafting wax.

I fit the scion into the channel and secured it in place with two wires with some protective rubber. It must be very tight. Try pushing on the scion – if it still flexes into the channel, it is not making good contact and must be tightened. The whole thing was then covered in grafting wax.

Next, I covered the graft with a small piece of damp sphagnum moss, and covered that with a piece of plastic mesh which was secured to the trunk with three wires. The purpose of this was twofold: 1) to protect the moss from birds and drying out too quickly, and 2) to distribute more even pressure over the graft.

Next, I covered the graft with a small piece of damp sphagnum moss, and covered that with a piece of plastic mesh which was secured to the trunk with three wires. The purpose of this was twofold: 1) to protect the moss from birds and drying out too quickly, and 2) to distribute more even pressure over the graft.

Here is the happy couple. The graft is circled in red. You can see that I did some trimming of the foliage around the graft to create a nice opening so the graft will still get good sun exposure.

There are lots of types of approach grafts, but I chose this method because I like the idea of the long channel creating a lot of surface area for cambium-cambium contact. No matter the method, I think the key points are to get good cambium contact, and lock the graft into place so it absolutely cannot move.

If the grafted branch continues to grow, that is a good sign but does not mean much. It will probably be next spring before I take a peek at whats going on underneath.


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.


Blue Alps Juniper Prep Work

I have a progression of my work on this tree in 2011 posted here. The species is Juniperus squamata ‘Blue Alps’, and it is an incredibly vigorous variety. It was crammed into a shallow pot this spring, but bounced back nicely. I detailed wired it in July 2011 and today and it has already outgrown most of its wire. So today, after coming back from the US National Bonsai Exhibition in Rochester, NY, I was itching to do some bonsai work so I removed the wire from this tree and gave it a trimming in preparation for its next round of wiring.

It may be worth noting that I unraveled the thin copper wire instead of cutting it away. Unraveling it is usually faster, makes less of a mess, and is better for the tree as it minimizes the chance that small loops of wire will be left on the tree that could later girdle or otherwise weaken a branch. I only unravel the detail wiring. The thicker copper wire applied to primary branches is cut away.

After a light round of scissor thinning, the tree went back on its bench. I will give it another month of growth until I have more free time to rewire the tree. Detail wiring this tree will probably take me the better part of a day.

Late March 2012 after repotting.

Today, before work.

After removing wire.

After a light trim. Only the strong middle shoots were cut back. The goal was just to balance the energy in some areas without weakening the tree overall.


Korean Hornbeam Cutting

I’ve been developing this carpinus from a neglected stump for about 6 years. Most of the primary branches had died back under the previous owner. I have been trying to build a new tree from thread grafts. It is coming along, but slowly.

Korean Hornbeam need to be cut back later than maples, otherwise they won’t backbud well. Usually this mean late spring, once the new growth has hardened off. This is also a good time to send through some thread grafts as defoliated branches will bounce back quickly, and smaller holes can be drilled since winter buds have not yet formed.Thread grafts can also be sent through in the late winter, but larger holes need to be drilled to get the branches through without rubbing off the large winter buds.

Healthy spring growth. I was planning on repotting this year, but never got around to it.

Leaves have just hardened off in the last week.

After cutting back. The tree will be moved to a sunnier location and fertilized heavily to encourage backbudding.

This branch was thread grafted a few years ago.

This is the first branch I threadgrafted on this tree. Funny that it is now supplying the whip for this year’s thread graft (note small branch wired inward)! Ahh… the circle of life… :)

This years little threadgraft, growing well. Note the size of the hole. This is the disadvantage to sending threadgrafts through in the winter. Larger hole = longer time period before the scion is large enough to start fusing with the trunk.

Some fruiting structures (catkins?) were spotted and removed. The branches that these grown on weaken dramatically. I try to remove the conspicuous flowers in the spring, but usually miss a few.


Pruning Ginkgo to Develop Ramification

Ginkgo have a bad reputation for developing ramification, but that doesn’t mean they don’t ramify at all – they just need some encouragement! Unlike other deciduous species like Maple or Elm that will develop some ramification even with improper cutting techniques, Ginkgo will barely ramify at if they are not cut properly. Still, even in the best of cases, Ginkgo ramification cannot hold a candle to that of maples… but that is just the character of the tree. They are still a great species to work on.

This post outlines the pruning techniques I use on my Ginkgo in USDA zone 6.

The first step is making sure the tree is growing strong. This tree was repotted in March but has grown better than expected.

I don’t cut my ginkgo until it is showing very strong shoots like this (about five pairs of leaves). This gives the tree some time to build up strength. I find that if I cut it too early, the tree doesn’t respond well.

Here is a typical gingko branch. The buds circled in red are backbuds. Ginkgo backbuds very well, and most buds open up in the spring. However, the problem with Ginkgo is that it is hard to get these backbuds to extend into twigs. Usually only the end of the branch (circled in blue) will extend during the growing season and the backbuds will just form winter buds. Therefore, you need to cut back the tip of the branch to one pair of leaves to redirect some strength to the backbuds. This is a rather weak branch, so the side buds may not even start to extend until the process is repeated next year. Again, I find that if the tree is allowed to gain some strength in the spring, you will have much better luck getting the backbuds to extend.

Here is a stronger branch after cutting the tips back. This branch is strong enough that I would expect some of the back buds to extend.

Strong apical nodes that have not yet extended may have 3-5 leaves instead of the usual 2. Cut off some leaves to leave just a pair. This weakens the outside of the tree and allows more light into the inside. This is especially important for the top of the tree since Ginkgo are very apically dominant.

After cutting. I will continue to fertilize the tree heavily and the process may be repeated again in the summer. Further leaf-thinning may occur throughout the season.

Really, the pruning techniques for Ginkgo are very similar for most deciduous trees. The development is just much slower and the end result less ramified. However, I’ve found that by using the above strategy, I can increase the twigginess of the tree by about 50-75% each season.


Larch from Seed

When I told of of my bonsai friends that I was planning on starting some larch from seed, he looked at me like I was dense and asked “Why?”

It is a fair question since we have access to very good wild larch in this part of the world. However, the good larch grow in rocky soil and larch in rocky soil send out just two or three large roots, therefore almost always having a bad nebari. Furthermore, collected larch have a rough and wild appearance. You will never find a collected larch with the features needed to make a “softer” classic upright bonsai. I’m not saying the classic look is better than the wild look. They are just different… and different is good in a bonsai collection.

Newly collected larch. The appearance is coarse and wild, with sharp curves and great bark. The nebari is buried, but trust me – its bad. Note the natural sacrifice branch :)

The question still remains – why larch? Why not something more classic like maple or black pine? There are three answers for that: 1) I see larch as one of the most beautiful species on the planet, 2) Larch can growvery fast in my climate when you want them to, and 3) Larch are bomb-proof and idiot-proof (so long as they are established). I am very lazy and hate dealing with exotic species that require special attention in the winter.

The only drawback I see in American larch is the slow bark development. For that reason, I am also growing some Japanese larch as apparently they bark up faster.

Basically I just want to produce some very nice shohin larch and also have some larch to plant in the ground as longer term “bigger” projects.

The process starts by making seedling-cuttings. The idea is you remove the taproot a few weeks after germination to promote lateral root growth early in the life of the tree.I’ve never done this with larch, but don’t see why it won’t work.

Little seedlings waiting to have their roots removed.

The best time to do this for pines is when the stem has turned reddish-purple, so I’m assuming the same applies to larch. Rooting hormone was applied after this step.

They were planted in a mix of turface fines and perlite. A top layer of something finer like sand would have been better, but I didn’t really have anything available. The seedlings are now in part shade and covered in a dome to increase humidity.


Ginkgo wire removed

This is the first spring where I am having trouble keeping up with the needed work on my trees. I am planning on doing some (more) culling on my collection soon, but much of that depends on the survival rate of my newly collected yamadori. I don’t have a huge collection (40-50 trees), but giving every tree the attention they need really takes a lot of time.

In the meantime, I am busy as hell. A friend was nice enough to remove the wire from my Ginkgo  for me 🙂 As a side note, this guy also has an amazing collection of fine mame and shohin sized pots and is always selling/buying. If you are looking for nice small pots, check out his website: Mame & Shohin Bonsai Pots.

As for the Ginkgo, many of the branches sprang back once the wire was removed. Kind of expected. Ginkgo is tough to wire because it scars so easily. Last year I wired it in late October and took off the wire yesterday (April 30). The branches seemed to have set better than in the past where I have wired it in March and had to take the wire off by early June.

I still haven't decided on a front for this tree. I think this side is more attractive, but the apex leans slightly back (it was not designed as the intended front by previous owners).

I think this is the original front of the tree, but I don't like the two symmetrical lumps about 1/3rd up the tree. They never used to bother me, but then my friend's wife pointed out that they look like bull testicles. Now that's all I see!


Ginkgo Frost Damage

I featured this Ginkgo biloba ‘Mariken’ in a recent post where I began the air layering process on it.

As expected, the unseasonably warm March we had has been countered by some freezing temperatures. Last week on a clear night it went down to -2 celsius. I brought most of my smaller trees in the garage, but this ginkgo was left outside to weather it. The damage is clear, but the tree is already starting to throw a new crop of spring growth.

I am not concerned about losing the tree (I’ve seen ginkgo bounce back from worse frost damage than this) but am wondering what effect this may have on the layering process. Time will tell, I guess.