Posts tagged “Chamaecyparis obtusa

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.


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.

Sigh.

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.