Developing older neglected trees!

Often we get the opportunity to acquire older Bonsai that have not been maintained. They pose special problems for redevelopment typically because they have grown out beyond suitable shape and form. This can be compounded if the root ball has been adversely affected as well.
This tree is an example of all of the above. When i purchased the tree it had been sitting in the same place for several years. The roots had escaped the pot through into the ground below. I severed several thick roots 3/4 inch diameter to lift the pot. The tree appeared healthy however the main root system was now below ground and the root ball within the pot had deteriorated. The tree has recovered over the past eighteen months.
The first step was an emergency repot to remove dead and or decaying roots as well as compacted soil. The remaining healthy roots were not trimmed very little and the soil was replaced with my regular inorganic mix.
The next step will be to grow out, cut back and create new growth in the interior. If that fails a lengthy program of grafting will follow.
Estimate another five years before substantial progress is made.
Fortunately the species is suitable for back budding. The upside is the trunk size and choice of primary branches to begin the process.
Has anyone else a similar project underway? Perhaps you could

share your project and approach.

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I look forward to watching this project develop.
May I request the approximate current height and trunk diameter?
Do you have an estimate of the age of the tree?
Thank you

I should have provided some of that information to begin with. The tree as it stands is approximately 30 inches high , the diameter of the base above the root flair is 4 1/2 inches. I would estimate the current spread of the foliage to be in the 36 inch range. Shimpaku , juniperus chinensis " Itoigawa"
Sorry no estimate on the age, my understanding is that it was developed for Bonsai and maintained but not styled or refined.

I’d probably do what you’re doing - get the tree healthy for a year, cut it back to get more buts, then consider grafting if need be.

I’m sometimes surprised at how slowly junipers recover if the tree is in bad shape. I’ve seen trees hold off on doing much for a year or two before they kick into gear.

Wow. Thank you for the detail. The trunk is much larger than I was envisioning!

Peter Chan talks about using sphagnum moss to revive tree roots. Is that a widely accepted procedure?

I have also wondered if the extra oxygen in hydrogen peroxide would encourage root development. Do you know if anyone has experimented with it?

I am not familiar with the context of Peter Chan’s discussion. However it is common professional practice to use sphagnum moss in a variety of manners to retain higher levels of moisture and prevent dessication.
In the case of roots this would commonly be a shredded cover on the soil mix after repotting.
I am not aware of any experiments with respect to the possible O2 benefits of Hydrogen Peroxide added to the water. I know it is accepted that it has anti-fungal properties when used as a soil drench. From an annecdotal point of view i have found it beneficial when working with cuttings primarily in a high humidity, low air movement situation to help prevent damping off.

A number of Chan’s videos show him putting trees with damaged roots into sphagnum moss with no other soil additives. His technique may relate to his air-layering experience. He reports a beneficial and healing effect, with faster root recovery. I believe he repots in bonsai soil after a couple of years of root development.
I will give the H2O2 spray a try on some cuttings. It sounds like it might answer a concern.
I wondered about using H2O2 as an emergency watering solution in situations where there may have been overwatering and subsequent root rot - mush like the soil drench you mention.

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I apologize in advance for posting a bunch of pictures - I’ve had a similar situation with a english yew I got a few years ago. When I first acquired it there was very little foliage and the soil was badly compacted. This is what it looked like after I scraped off the top 3 inches of soil:


I’m amazed to find I even took a picture - I assumed it would die pretty much immediately!

To water it I had to take a screwdriver and make several holes in the root ball. This was in September of 2017. I left it alone until the following spring, then I soaked the rootball and very carefully removed soil all around the ball until I just started hitting live root tips. I only used my fingers because yews have delicate roots. This was a little more than a third of the volume overall. I also dug straight up the center of the rootball to the base of the trunk - this part was entirely rotten and dead. I packed it with pumice to help dry everything out. I surrounded the roots with pumice and akadama and put it back in the same pot. It leafed out a little bit that spring:



I didn’t do anything else to it.

The following spring I pulled it to repot again and discovered a lot of new roots! They were growing out of the compacted soil and into the akadama (I tended to water the akadama more to try to get the roots to go into the better soil). You can see that half of the tree is actually entirely dead:


I removed about half the soil this time since the roots were going well, and removed a lot of dead and rotting wood below the soil line. Then I moved it into a bonsai pot with a mix of about 2 parts akadama and 1 part pumice (I worry about the sharp lava rocks possibly damaging the roots). The dead areas are surrounded by only pumice, since I figure they need to stay dry so they don’t rot anymore:

It leafed out a LOT this year and even flowered:

Right now the plan is to leave the roots alone for awhile. In a few years I’ll pull it back out and remove the last of the compacted soil. This is a yew though, and they’re pretty vigorous, so you may want to move more slowly. I’ve never once trimmed roots on this tree (yew roots are fleshy and delicate) and I’ve tried to be careful with it. I’d say the most important thing is to be sure not to disturb any new roots - remove soil right up until you see them though so they can escape the clay and get into good soil. Then gradually remove the old stuff a little every year.

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Thanks for sharing. You will probably find that the new roots have invaded the pumice. I use it exclusively with collected trees for. That reason. No need to worry about the sharp edges in my experience with either conifers or deciduous.
Yew are tough, but nice job resurrecting that one!
The juniper above has been repotted on two occasions to change out the compacted soil and is now in regular bonsai mix since the spring of 2019. Recovery is well underway, waiting on the vigorous growth to tell me it is time to cut back.

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