Acer Palmatum 'Beni-Chidori'

[Bnana]

All organisms have an immune system, including trees. Many bonsai are grown under poor conditions or are weak (sickly) varieties.
If you stick to species that grow well under your conditions and avoid fancy, sensitive varieties (especially for Japanese maple) you'll find that fungi and pests are not such an issue.

 

[ajm55555]

That sounds like pseudomonas syringae, a bacterial infection. Repotting and working the roots on a maple in cool wet weather during spring seems like the time this bacterial organism can flourish… I’ve never had a tree survive.

Exactly @Dav4!
What was your solution? No more Deshojo&Co or did you find that if you strictly follow some rules (like the one you said), super sterylize the tools, seal the cuts, anti-fungal, they make it? Other ones?

 

[ajm55555]

I can offer that my favorite solution of 2 tablespoons 3% hydrogen peroxide in a quart of water is an antiseptic (i.e., it nixes most fungi AND bacteria) can be used as a root dip when repotting.

Interesting, thanks for the tip.

 

[Dav4]

Exactly @Dav4!
What was your solution? No more Deshojo&Co or did you find that if you strictly follow some rules (like the one you said), super sterylize the tools, seal the cuts, anti-fungal, they make it? Other ones?

It does seem like certain cultivars were more susceptible, and for me, that was kiohime and kashima. I haven’t worked any more of those varieties… they’re dead so. In all seriousness, waiting until the perfect time for root work and perhaps really babying the trees afterwards- bottom heat, perhaps- would work. My regular palmatums continue to thrive with my typical aggressive root work and aftercare.

 

[Canada Bonsai]

My Japanese Maples got a lot healthier when I started keeping them out of the late-winter and spring rain. I use a coldframe-turned-greenhouse in spring and fall, but I assume a clear sheet of polyethylene overhead might help. Might just be coincidence, or it might have been the difference maker, i have no way of knowing.

(Of course, i also sterilize tools, work area, etc. etc.)

 

[ConorDash]

This tree has grown well this year, minimal damage to foliage over the year and good extensions.
I removed unnecessary branches, and reduced all keepers to 1 pair of leaves.

Mainly wanted to clean up the top, to try and get a better apex on the tree, transition in to a new leader. Wired the leader for movement and change of direction too.

3 - urw9zhL by Conor Dashwood, on Flickr
1 - TVbVrJy by Conor Dashwood, on Flickr

5 - mQXCHBO by Conor Dashwood, on Flickr
6 - IpebYKr by Conor Dashwood, on Flickr
7 - m6PqMwy by Conor Dashwood, on Flickr

 

[clem]

Nice work
concerning the infection your JM had this spring, (maybe pseudomonas) why not trying, next spring, when the new leaves start to open and developp, to spray a fungicide with copper sulfate ? I spay bordeaux mixture or a mix of mancozebe + copper every spring on my JM cultivar in spring , on the young leaves, and they have no infections up to now (i cross finger). I also cultivate my JM in a ventilated greenhouse and i only water the soil (not the leaves), so maybe it also prevent some diseases...

 

[ConorDash]

Nice work
concerning the infection your JM had this spring, (maybe pseudomonas) why not trying, next spring, when the new leaves start to open and developp, to spray a fungicide with copper sulfate ? I spay bordeaux mixture or a mix of mancozebe + copper every spring on my JM cultivar in spring , on the young leaves, and they have no infections up to now (i cross finger). I also cultivate my JM in a ventilated greenhouse and i only water the soil (not the leaves), so maybe it also prevent some diseases...

Thanks, good info.
I never water leaves anymore, to protect further against infection. Ive had enough for the years I've been doing this, so now i do everything as best I can to prevent infections.
I have looked at buying some mancozebe, came highly recommended from Mach too, but its not so easy to buy in the UK.
Ill look in to the copper sulfate too, thank

 

[ConorDash]

Might be finally on to some kind of good track with this maple now.. maybe. Apex grew well and was cut. Most of the tree is left just maintenance pruned, but would like to grow out the primaries all around it, get some bulk on them to be in better proportion with the fat bottomed trunk.
Will try to keep the apex branches, shortened, to keep internodes short.



Also a picture from last year that I didn't post, from 11th May, very glorious colours.

 

[wooden_heart]

@ConorDash

it's good to see that your tree recovered this year from the previous years issue with it's leaves. My Shin desjoho had similar issue this year, young leaves showing signs of being burnt, exactly same as your previous photos, lots of deformities to leaves as well. I though the repotting caused it, but I have same tree which I didn't do a repot and experiencing same issue. My theory, during winter time, we had this really bad winter (I leave in Vancouver BC Canada), I don't have a green house, to take care of my trees, I placed them inside my garage when temperature dips really low, for trees that I can't bring in, I cover it with some plastic. Maybe by doing that, I exposed the tree into wrong signals in terms of temperature, buds swell at least a month early, it was still very early in spring, temperatures fluctuates between freezing at times, buds already about to break. I think buds opened up too soon and was exposed to weather prematurely causing leaves to get somewhat burn't and damage, that's my theory

This year I am going to try something different, regardless how bad the winter gets, I will just leave them outside, see yield different result

Cheers!

 

[ConorDash]

Grew well, put on bulk. Mostly shortened now, some branches left long for further taper development. With a stocky base and FAT ASS, I want this maple to have some thick primaries. Also I foresee the canopy being large, perhaps even out of proportion with the trunk but, I want that.