Help with Yamadori root growth

Wondering if anyone has experience with this issue. I have recently repotted a collected tree from 2016. The recovery container was failing and it needed to be repotted as a precaution. My concern is the care going forward. The roots had only grown significantly on one side of the tree, due to the original root pad, the recovery container, and the planting position. Now it is in a larger pot and close to 50% of it is unoccupied by roots, think of the tree and the root system to look much like a capital “L” My concerns are the new pot holding too much water on the empty side and how to fertilize? Should I only fertilize the root side of the pot? Both sides to try and encourage growth throughout? Empty side to try and draw roots out for balance? I figure I will just have to be careful not to over water, especially early on as the balance is off considerably. I hope there is some advice for me. Thx.

1 Like

What species of tree is it? One of the biggest things I took away from the tertiary content video on potting yamadori was Ryan saying never to over-pot a newly collected tree. I have had a not so great survival rate with my collected American Hornbeams in the past couple years, 3 of 5 have failed and succumbed to some type of fungal infection. Now, thanks to mirai, I believe I was putting them in too big of containers with too much soil and it stayed too wet for too long between watering. I would say you may want to keep it in a smaller container so there’s not a consistent wet spot (imabalance of h2o and o2) on the side where you need roots to grow.

Ponderosa Pine. It’s not exactly newly collected, spring 2016 collection date. And as far as the pot goes that’s another issue. Due to it’s size and angle the overpotting was kinda needed for stability, and counterweight. The tree is top heavy because of the lack of roots to one side. It will balance out in time, I’m just trying to encourage that ASAP. Again this was not the plan, but more making the best of a bad situation. It is currently well braced and supported, and in a long time home pot wise. If I had it to do over again I would have built a new grow box for it but alas here we are.

1 Like

I guess just try to be vigilant about not letting that area of soil stay too wet? What’s the container like? If its a wood box you put together maybe you screw in a board inside the box like Ryan did in that video. To reduce the amount of soil on that side, then take the board out and refill with soil when the roots have caught up? or take that idea and adapt it to your pot somehow?

If you have it in pumice, you can’t really overwater the side without roots. I’d be more concerned about the side with roots, if it still has a lot of field soil. I would fertilize evenly, on the assumption that the microbiome and roots will spread to the unoccupied side.

1 Like

Thx HnD. Yes the mix is pumice heavy. 2 pumice 1 expanded shale 1 DE. It is top dressed with sphagnum/collected moss by the Marai method. It does have a fair amount of field soil left.

Moon…I collected several Pondys in Colorado 3 years ago. I like to use those vinyl cement mixing tubs that Lowes has (for about $3 each) for yamadori containers. Holes are drilled into the base, and under the lips which are on the 4 sides. Once a tree is in the tub, I use guy wire to hold it in place while gently adding soil, in the correct manner. I take a little of the peripheral field soil away, but leave field soil directly under the trunk. This is because of the micro environment which exists there, and the tree will use during recovery from being collected. As High-N-Dry mentioned, if the tree is in Pumice, you really can’t over-water, since Pumice is so free-draining.
To help the tree along, I also fertilize, but only after the local temps are above 40F.
Hope this helps…


A little late to the party… Do you mean you can’t over water because pumice is in the category of inorganic soils? Bc pumice’s job among the different inorganic substrates is to hold water. That is throwing me off.

Btw, thanks for mixing tub tip, very cheap.

Patience. Ponderosa is SLOW growing.
Is the foillage healthy? You’re probably fine.
Dallas is not an opperant environment for pondys.

Thanks guys. My pondo is doing well it seems, foliage is green save one small branch that has died off. I have it tilted to better aid drainage and I have new buds. It’s been about 8 weeks since repot and I will start fertilizer now. I guess I won’t really now how well it has done until next years growth.

Pumice holds water in its pores, but it allows plenty of air into the spaces between particles, no matter how much you water.

Hornbeam try 100% perlite May provide you with a different result in collection. I’ve seen it done successfully at the local club.

1 Like

@FloridaBoy Yea actually the hornbeams I collected last spring, 2 of 3 survived, and were potted in 95%perlite with a little fur bark and horticultural charcoal making up the other 5%. Better than the previous year of 2 of 2 collected hornbeams dying. Perlite definitely is a fantastic option for collected trees, it’s very similar to pumice in it’s function but is much cheaper and widely available. It can stay too wet for some things though if you’re really going out of your way to over water and keeping the tree in the shade too long and have overpotted. I’m sure it was the overwatering that killed the one hornbeam I lost last year.

I also potted 10 collected hawthorns with barely any fine roots into that 95% perlite mix last spring and they have all recovered super well. I believe in the power of perlite for sure. It’s very underrated in the bonsai community I feel.