The Japanese Maple Experiment

Maple #1

Maple #2

Since it’s repotting season and I was itching for a maple side project, I asked Mr. Tanaka if I could develop these two Japanese Maples. These Japanese Maples are called Arakawa Momiji which literally translate to Rough Bark Japanese Maple. Unlike the typical Japanese Maple with smooth bark, these maples develop small and fairly hard bark plates. Both of them have nice trunks and were field grown. About 10 years ago, they were put into bonsai pots and sat at the overflow field that Mr. Tanaka owns. A few weeks ago, I was watering the overflow field and stumbled upon these two and thought it was be great if I could practice developing them during my time here in Japan. I showed them to Mr. Tanaka and he gave me the green-light to develop them during my own time (as if I had plenty of that… ;o)).

The first thing I decide to do was repot both of these trees. As I was repotting the first tree, Mr. Tanaka glanced over and said that I should restart all the branches. We both decided to repot both trees and during the Spring of 2013, I will cut off all the branches and force the tree to bud out at the cut branches and hopefully the trunk as well. Mr. Tanaka then added that putting the trees in the ground would make them stronger then in a pot. At that point, we both decided to repot one tree in a bonsai pot and the other tree in the ground as an experiment (for the blog). I’m going to let both trees grow for the rest of the year and in the following Spring, cut off all the branches and see how both trees respond. In this post, I’m going to show you what I did with each tree and continue to write more post about them in the future as they continue to develop. Let’s get to work!

Arakawa Momiji #1

The current front. I especially like the movement and taper of the trunk.

Here is the root ball after I removed it from the pot and cut some roots. I will post the process of repotting in a future post.

Note on repotting:

Deciduous trees tend to grow slow after they are repotted. The following year, if the tree isn’t repotted, it will grow even stronger. There is a point though where the tree will become so root bound that it starts to slow down again. Since this tree hasn’t been repotted in about 10 years, the tree itself, though healthy, is slow. If the tree was repotted a couple of years ago, I could have bare rooted it with no problems. Now that the tree is in a slow state, if I bare rooted it, I could potentially kill it. I decided to go easy on the repot and keep more roots this time. Next year when I repot again, I can be a bit more aggressive with the roots.

When you’re repotting your own trees at home, you should always evaluate the tree and put into consideration how strong it is to determine how aggressive you can get with the roots.

This isn’t the best picture but it does give you an idea of what the cork bark looks like. The bark develops fairly quickly on this tree. Branches that are about 4-5 years old will start to develop cork.

Here is the tree in a new wider pot. I tilted the tree to the right a bit to show off more of the root spread (nebari) on the tree’s right. I then put some sphagnum moss on the top soil to maintain the moisture level to help the tree recover from the repotting. I set the tree in a nice sunny spot and will start to fertilize the the tree in the next couple of weeks. The soil mix I used for this tree is 70 percent medium-hard akadama, 15 percent coarse River sand, 15 percent pumice with a splash of charcoal. The granular sizes ranged from small to medium. This is about the typical mix we use on our medium to large deciduous trees.

Rough Bark Japanese Maple (Arakawa Momiji) vs. Typical Green Leaf Japanese Maple (Yama Momiji)

Rough Bark Japanese Maple grow pretty much the same as a typical smooth bark green leaf Japanese Maple. The new leaves come out green with a red border. As the leafs mature, they will turn completely green. They both are worked the same and feed the same during the growing season.

The benefits of using this type of maple is that the bark is very interesting and their wounds actually heal faster then a typical Japanese Maple. Last year, I cut of a 1 inch (2.5cm) branch at the trunk and the wound as already callused over. Other then the bark and healing speed, they are pretty much the same as a Green Leaf Japanese Maple.

Arakawa Momiji #2

This one is going into the ground.

Since I plan on putting this tree in the ground, doesn’t mean I just pull it out of the pot and plop it into a hole in the ground. I still have to do the root work just like a regular repotting. This photo is a good example of finding the true root spread (nebari) before working on the rest of the root ball. Normally, I would start on the bottom of the root ball first, but in this case I don’t know where the root spread is yet so I have to find it first. If I don’t do this first I may end up taking too much from the bottom. Now that I know where the root spread is, I can focus on the rest of the root ball.

Here is the root ball cut and cleaned up.

To The Field We Go!

In early March, Mr. Tanaka, Juan and myself made a small growing area at the overflow field (it’s not always sitting in a comfy chair in the workshop ;o). This area is about 12 inches (30.5cm) deep with used bonsai soil (akadama, pumice, coarse river sand). I took a shovel and dug about 8 inches (20cm) deep, leaving a slight hump in the center.

Next I placed a thick plastic bag on top of the hump. This plastic will help force the roots to grow outwards as oppose to downwards. Some people use a large tile or wood board instead.

Next I put a small amount of soil on top of the plastic.

Here’s the tree on top of the mount.

Next I filled the hole with soil and compressed it with with my foot. I think you can see some of my foot prints in the soil! :op

Last thing I did was water the tree.

So all we can do now is wait and see how both trees will grow. Which tree do you think will grow stronger and faster? Most would say the the tree in the ground would and it is a very much proven fact. The reason why I’m doing this experience is for couple of reasons.

1. Practice what I have learned in developing deciduous trees.

2. Trying to figure out if the gains of putting a tree in the ground as opposed to a pot, is worth the time in creating a growing ground in the future.

3. (Most important) I’ve always heard from my first year doing Bonsai till now that putting trees in the ground will make them grow faster and stronger. One thing that has bothered me in Bonsai is that many people will always tell you how this and that works well, but they never did it themselves. It’s always something they heard from other people and just accepted it to be true. Once I came to Japan, some of those truths turned out to be incorrect and I thought to myself, “Wow! There is a lot of misinformation out there and I just assumed it was correct because that’s what people were saying over and over.” With this experiment, I can at least say that I tried it and it worked… or maybe not work… we’ll see. For you readers out there that haven’t tried it or can’t (let’s face it, we don’t all have large backyards), you can at least have some sort of visual evidence that it works or doesn’t.

The Fall

Both trees will continue to grow during the Spring and Summer. In the Fall, they will both slow down and I’ll take some pictures of the new growth to see which grew faster. I’ll keep you all updated with plenty of pictures.

I got more projects in the works so if you liked this post, there will be more coming soon!

Now you can say you were there at the beginning! Thanks for reading everyone, and I mean it!

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