Larch Root Rot

[Meh]

I purchased a nice field-grown Japanese larch last summer that was apparently in great health. It was still growing in muck, and the nursery container had side drainage but no bottom drainage.

The buds are swelling (Spring! Woohoo!) so yesterday I went to repot it into proper draining soil. What I encountered was a pot full of rotted roots--one side of the root mass was completely rotted away and the roots on the bottom of the pot on the healthier side were also rotted considerably.

I know that bare-rooting larch is not a good idea, but given how bad the roots were I removed as much field soil as I could, cut away the rotted wood (all the way to the trunk on the bad side) and repotted in 100% akadama in a proper container.

I have two questions I'd like to pose to the larch experts out there:

1. What should I have done differently, if anything, to address the problem?
2. Is there any hope of new roots forming on the bare side? If not, is my best option to do a ground layer above the current roots and start over?

Thanks in advance!

 

[Oleg]

I lost a pine about 4 years ago, what I learned was there is a pathogen at work, it's in the soil on or in the pot and in the remaining roots. There are root drenches for the tree but it sounded like they were far from a sure thing.
Good luck

 

[Meh]

I lost a pine about 4 years ago, what I learned was there is a pathogen at work, it's in the soil on or in the pot and in the remaining roots. There are root drenches for the tree but it sounded like they were far from a sure thing.
Good luck

Thanks, I guess I can't rule out disease, and a drench may not hurt as a precaution. But my operating theory is dieback due to lack of oxygen and waterlogging in light of the terrible muck it was planted in.

 

[Leo in N E Illinois]

I'm in Zion, north of Waukegan, I suspect you are not too far from me.

If you have a large tree in a small bonsai pot, Akadama is good, as it holds lots of water. If you have a medium or small larch in a nursery can size pot, the Akadama may hold too much water. I use pumice, or perlite as the major soil component for larches in nursery pots and training pots. Better draining, and better air penetration. Currently I do not have any larches, I'm speaking from past experience.

Are you a member of the Midwest Bonsai Society, that meets on the first Monday of the month, 6:30 evening at the Chicago Botanic Garden? Or are you far enough north that you would consider Milwaukee Bonsai Society, which meets at Boerner Botanic Garden, Hales Corners, southwest Milwaukee county. They meet first Tuesday of the month at 6:30 pm. From Zion travel time to either location is roughly equal. Both groups are active. Milwaukee is a more blue jeans and flannel shirts crowd. Parking is free, and you can attend a few meetings without joining. Chicago group is more business casual. Parking fees are high, becoming a CBG member is financially necessary to avoid high parking fees. Both groups are very mixed, members from all walks of life. And both groups are pretty active, with classes, visiting artists and various workshops, annual exhibits and other activities.

There is a 3 dimensional, actually 4 dimensional if you include time, aspect to bonsai that simply is not well served by the 2D screen of a laptop. You can be as active of as much an observer as you like, but there is a real benefit to seeing in person what is talked about on this forum.

 

[Meh]

I'm in Zion, north of Waukegan, I suspect you are not too far from me.

If you have a large tree in a small bonsai pot, Akadama is good, as it holds lots of water. If you have a medium or small larch in a nursery can size pot, the Akadama may hold too much water. I use pumice, or perlite as the major soil component for larches in nursery pots and training pots. Better draining, and better air penetration. Currently I do not have any larches, I'm speaking from past experience.

Are you a member of the Midwest Bonsai Society, that meets on the first Monday of the month, 6:30 evening at the Chicago Botanic Garden? Or are you far enough north that you would consider Milwaukee Bonsai Society, which meets at Boerner Botanic Garden, Hales Corners, southwest Milwaukee county. They meet first Tuesday of the month at 6:30 pm. From Zion travel time to either location is roughly equal. Both groups are active. Milwaukee is a more blue jeans and flannel shirts crowd. Parking is free, and you can attend a few meetings without joining. Chicago group is more business casual. Parking fees are high, becoming a CBG member is financially necessary to avoid high parking fees. Both groups are very mixed, members from all walks of life. And both groups are pretty active, with classes, visiting artists and various workshops, annual exhibits and other activities.

There is a 3 dimensional, actually 4 dimensional if you include time, aspect to bonsai that simply is not well served by the 2D screen of a laptop. You can be as active of as much an observer as you like, but there is a real benefit to seeing in person what is talked about on this forum.

Thanks Leo! I actually live right next to the Chicago Botanic Gardens and I am a card-carrying member of the midwest bonsai society. I have only been to a few meetings as I found them quite dry--not a lot of actual hands on work being done. I know the Chicago chapter holds monthly bring your own tree workshops at the Garfield Park Conservatory but I can't make that work with my schedule.

I do go to (paid) workshops with Chris Baker, the curator at CBG, and I will be signing up for some of the guest events at the Hidden Gardens in Willowbrook this summer. I find those hands-on events more rewarding and educational. But maybe I just got unlucky with the particular MBS meetings I attended? What's been your experience?

 

[Oleg]

This suggest that it is possible to recover.
https://www.pennington.com/all-products/fertilizer/resources/recovering-from-root-rot

 

[Leo in N E Illinois]

I usually head north to Milwaukee, but from CBG that's over an hour drive, probably 1.5 hours. Check the Milwaukee Bonsai society website, http://www.milwaukeebonsai.org

They post their newsletter on line and you can read about upcoming artists and workshops. If you see one you like you can join the society that day and register for the workshop or classes. You can certainly attend a few meetings with out joining. Or join if you want. Milwaukee BS is pretty relaxed. All clubs go thru cycles of activities and doldrums. In part because it is hard to get active volunteers to help organize things. MKE has shared artists with CHI a number of times. I think Mark Feilds is coming soon and will be in both Chicago and MKE on succeeding days.