Chuhin Broom Elm

[markyscott]

With spring growth in full swing in Houston, I'm in the busiest time of the year. Trees in development are fertilized heavily - solid fertilizer on top and liquid fertilizer every weekend. Trees are pushing huge growth - it seems like they change every time I look away for a minute. That means wiring and branch selection every weekend. The more I learn about bonsai and the more my trees develop, the more I realize that I can't keep so many of these darn things. I work on them continuously in springtime.

Here's one I thought I'd share - I wanted to highlight this project because it's fun and can be done with easily accessible and affordable material for everyone. This tree started out as a 10 gallon nursery tree I bought at 75% off in the fall of 2012 (sorry - no pictures back then). But we've all seen them - stick straight trunk with no taper and no lower branching and about 8-10' tall. We would all walk past these things. But broom is one style that lends itself to this kind of material. And it was cheap. So I thought I'd give it a try.

 

[markyscott]

Unfortunately, I was really bad at taking pictures back then, so you'll have to use your imagination for the first part of the development. Here are the highlights:

1. Purchased fall 2012
2. Chopped the trunk to about 3" in early spring 2013 and repotted into a training pot
3. At the cut, I wrapped it with garden hose held in place with a hose clamp to reduce swelling at the cut. Then I let it grow until 2015.
4. In 2015 I repotted. Here's the first lesson - make sure you take care of problem root issues early. I didn't and Febuary of 2015 was basically a reboot of the root system. I've got some pictures of that:

I had it planted on a board, but I'd left some thick roots. In the intervening years since the original repot, the thick roots had just gotten thicker and I had very little root development along the trunk. So take care of this early so you don't have to go back and do it again later.

I know it looks scary if you haven't done it before, but this is no problem for healthy Chinese elm. I had great growth last growing season.

 

[markyscott]

This year it's been exploding. Looks a bit like Cousin It. Time to go a straighten all of that out. I like to do this in spring - not because you put all that much movement in the branches, but because you have much better control of the angle the secondary ramification leaves the branch. If you wait until fall, many of the branches you've grown will exit at an uncomfortable angle and you won't be able to correct them. But with softwood shoots, you are still in control. Here it is at the beginning of work.

 

[markyscott]

Some things to think about as you wire it up.

• Reduce the number of shoots at each branch union to two.
• Prune back the stubs from the winter cut back to a 45 degree angle and cover with cut paste.
• Cut back excessively strong shoots, but keep the growing tips on the weaker shoots to help balance the trees energy.
• Prune new shoots growing from the old chop - those were already selected and we don't need any more.
• Reduce the number of branches growing toward the interior of the trees. We don't want that to get too crowded.
• Don't put too much movement on the branches. The interest in a broom is the fine detailed ramification and the shoots should be trained to grow pretty straight.

Here are some pictures of the work.



All done for now.

 

[Cypress187]

Wow, those where the only roots left from that huge pot? I see roots dangling on the bottom, where are those?

 

[markyscott]

Wow, those where the only roots left from that huge pot? I see roots dangling on the bottom, where are those?

The pot was full of roots - they were just starting from the wrong place - at the end of roots too big to keep. Had to start over - this was all I kept. That was a little over a year ago - I'm sure the pot is full of roots again. This time they'll be better - finer roots right from the trunk. I'll but it back on the board next repotting season.,

 

[KennedyMarx]

Is that a Chinese elm or another elm type? I've never seen any type of elm for sale here in a big nursery can. One place had some S shaped elms in bonsai pots but the prices were ridiculous.

 

[Cypress187]

Maybe it's a stupid question but why are those branches all wired but still staight as an arrow?

 

[CWTurner]

This time they'll be better - finer roots right from the trunk.

That's a scary amount of root pruning. How do you know that the new roots will grow where you want them and not from the stubs again? Or did you cut way back on some thicker roots to make those stubs, and it wasn't pictured?
CW

 

[Adair M]

LOL!!

I swear we are living parallel lives!!

I had a zelkova that when I bought it, the swelling at the chop was already pronounced, and I tried to contain it by using a hose clamp! After two years, with no appreciable improvement (I started too late), I gave up, and air layered it off, making a clump out of it.

I was thinking the old trunk would then make a separate tree, and I could have another broom. Unfortunately, the trunk never budded.

 

[Adair M]

Maybe it's a stupid question but why are those branches all wired but still staight as an arrow?

He wired them to get the angle they emerge from the trunk right.

 

[markyscott]

Is that a Chinese elm or another elm type? I've never seen any type of elm for sale here in a big nursery can. One place had some S shaped elms in bonsai pots but the prices were ridiculous.

Chinese elm. They're sometimes marketed under the common name Drake elm for Ulmus parviflolia "Drake". Also sometimes as Lacebark elm. But, in my area, you can pick them up easily at specialty nurseries and sometimes at the box stores. That's where I got this one.

 

[markyscott]

Maybe it's a stupid question but why are those branches all wired but still staight as an arrow?

As Adair said, the key is to get the angle at the point where the shoot emerges from the trunk or main branch right. You pretty much have to do this when its green. After the wood has lignifies. It's too difficult to change the angle. But with broom style, not too much movement on the branches. All those will be cut back later in the growing season. I wire out a long way on the branch I know will be removed so that I can ensure that the light doesn't get blocked and the branches don't fall down as the continue to grow. Shoots are already 2' long - they could be 4'-5' by the end of the growing season if I let them be. But when the wire starts to cut in, I'll pull it off and cut back. Then the new shoots will extend and I'll wire them again. Should be able to do that 3x this season - that's how you build the ramification.

 

[Adair M]

Scott:

This is the only picture I have from the magazine, maybe I can get another:



But you are roughly at the first picture on the right, the one marked '80.

But look at the partial photo to the right of it, marked '76. See the bit of wood with the concave carved end?

I believe Ebihara did that to his zelkova. Removed a good bit of the heartwood at the very beginning. Then, once he got the buds, and selected the ones to grow into his main branches that we see in the 1980 picture, he had carved V cuts in between them. Having the center carved out before made it much easier.

My question would be "what about the water in the cup of the trunk?"

In the 1983 picture, there appear to be more branches growing towards the interior of the main ones pictured in 1980. I wonder if he grafted those in?

 

[markyscott]

Scott:

This is the only picture I have from the magazine, maybe I can get another:

View attachment 100949

But you are roughly at the first picture on the right, the one marked '80.

But look at the partial photo to the right of it, marked '76. See the bit of wood with the concave carved end?

I believe Ebihara did that to his zelkova. Removed a good bit of the heartwood at the very beginning. Then, once he got the buds, and selected the ones to grow into his main branches that we see in the 1980 picture, he had carved V cuts in between them. Having the center carved out before made it much easier.

My question would be "what about the water in the cup of the trunk?"

In the 1983 picture, there appear to be more branches growing towards the interior of the main ones pictured in 1980. I wonder if he grafted those in?

My favorite Zelcova. Here's the 1976 picture.



I carved out the center this past winter. I'll probably carve out a bit more next January - I think it was concave like you pointed out, but probably not a V cut. The original chop is probably 1/2 filled in already. Looking at the 1980 picture, I'm not sure I see any V cuts - maybe they're just the intersection between adjacent shoots.

 

[markyscott]

That's a scary amount of root pruning. How do you know that the new roots will grow where you want them and not from the stubs again? Or did you cut way back on some thicker roots to make those stubs, and it wasn't pictured?
CW

Hi CWTurner. You know - I wasn't nervous at all. The tree was strong and in good health. And it's a Chinese elm - I know they can tolerate severe root work. So no prob.

And I'm sure that roots will sprout from the stubs and, hopefully, at other places around the trunk. I'm also sure that there will be some bare spots. In that case we'll be grafting roots in places. I'm sure with the hard cut back though I'll get a lot of new roots forming close to the trunk.

 

[markyscott]

5 weeks since wiring - the wire is cutting in and must be removed. On deciduous trees, it must be watched carefully - they grow when you're not looking. Growth has been very strong. In development you want strong growth and big leaves. At this stage, we're not concerned with leaf size and we don't cut back after a few leaves grow out. We're building branch structure and the branches should be allowed to extend until they thicken sufficiently. If one branch is getting too thick, we can clip the growing tip to allow the weaker branches to catch up. This is how we achieve balance in deciduous trees.

 

[markyscott]

Today, just the wire comes off. I may apply more wire to support the extending shoots. Then I'll cut back hard after a few months of thickening. The tree is strong. It will explode with new buds and we start over again. Let the shoots extend and then wire. Then let them thicken, unwire, cut back. I might get two more growth cycles this season. Things really slow down in the summer.

 

[markyscott]

More seasonal work. Here's a really strong branch. See? Look how far it's extended this year - over 2'.



As it's extended, it's thrown side branches. However, other shoots the tree has thrown are much weaker. We want balance, so the key is to slow this branch down so the weaker growth can catch up. That means cutting back the leader to one of the growing back branches. If you really want to slow it down, cut the growing tip of the side branch too. This is how we balance the growth in broadleaf trees. Let's cut back to here - just above the side branch the tree has thrown:



Here's how it looks after we've cut it. Now we need to wire it out to make the side shoot the new leader. We're not concerned with movement on the branches right now - just the angle the branches extend from the trunk. This winter, we cut back hard. Next spring, we do it again. This repeated process of growing out and cutting back is how we create taper and ramification in the branches.


Wired out (again - the second time this season):


The shoots in the center should be allowed to grow long and strong. They should be the thickest in the end. Even brooms have leaders. So we don't cut the growing tips on those and the shoots should be wired straight up. The shoots on the side should be smaller in the end, so we slow the growth on the strong ones and wire the shoots down at an angle.

 

[markyscott]

When we cut back this winter, it'll be about to here.