Shishigashira Maple and Frost Impact

Leon

Sapling
Messages
31
Reaction score
41
Today I noticed the frost damaged branches are spreading further down the tree. Is this normal because this tree experienced a random freeze in April in the south. It's been recovering but I noticed more black surface are showing up. A post before suggested I leave along to recover naturally but I see more black spreading. The tree was very healthy when it was purchased in April 2019. Please review photos and comment. I might just over thinking.
 

Attachments

0soyoung

Imperial Masterpiece
Messages
5,438
Reaction score
8,216
Location
Anacortes, WA (AHS heat zone 1)
USDA Zone
8b
Probably not frost damage. Maybe a pathogen.

Out of doors, exposed to the cycles of deepening frosts in fall, it can be hardy to zone 5's subzero (F) temperatures. In a cold, dry, but sunny winter conditions, the cambium can desiccate on the sunny side and is commonly called 'winter burn' - this doesn't seem to be indicated in your pix.

Pseudomonas syringae is a winter pathogen and a possible cause. The bacterium can gain entry through bark damage but usually during freezing by being a nucleation site for forming ice and so is associated with being a winter disease. It doesn't seem to be fatal to larger acer palmatums, but on bonsai size, I dunno.
It also could be fungal - 'flame out' this time of year could indicate verticillium for which there is no cure. Verticillium is soil-borne and gains entry by being 'rain splashed' up into a bark wound. It gets into the xylem and so progresses upward from the point of entry.
There are other possibilities that are less common and/or not so well-known.

The pix are not clear enough for me to tell for sure if there is bark damage on this branch, but none seems to be indicated. I also cannot tell if that bare branch has viable buds. If it does not, it is dead anyway and keeping it is just inviting more trouble, so remove and discard it after doing a little autopsy (verticillium makes dark, almost black streaks in the wood, for example). Be sure to sanitize your pruners afterward (e.g., wipe the cutters with 70% isopropyl alcohol).
 

amatbrewer

Mame
Messages
219
Reaction score
247
Location
Yakima Wa
USDA Zone
6b
My Shishigashira was out all winter, and despite record cold temps as well as a late session hard freeze (after it started to open buds) it survived with no damage that I can find. So I am doubting frost damage unless it was REALLY cold.
 

discusmike

Omono
Messages
1,350
Reaction score
432
Location
elkton,MD
I have had one in the ground for atleast five years with no winter issues
 

Leon

Sapling
Messages
31
Reaction score
41
Probably not frost damage. Maybe a pathogen.

Out of doors, exposed to the cycles of deepening frosts in fall, it can be hardy to zone 5's subzero (F) temperatures. In a cold, dry, but sunny winter conditions, the cambium can desiccate on the sunny side and is commonly called 'winter burn' - this doesn't seem to be indicated in your pix.

Pseudomonas syringae is a winter pathogen and a possible cause. The bacterium can gain entry through bark damage but usually during freezing by being a nucleation site for forming ice and so is associated with being a winter disease. It doesn't seem to be fatal to larger acer palmatums, but on bonsai size, I dunno.
It also could be fungal - 'flame out' this time of year could indicate verticillium for which there is no cure. Verticillium is soil-borne and gains entry by being 'rain splashed' up into a bark wound. It gets into the xylem and so progresses upward from the point of entry.
There are other possibilities that are less common and/or not so well-known.

The pix are not clear enough for me to tell for sure if there is bark damage on this branch, but none seems to be indicated. I also cannot tell if that bare branch has viable buds. If it does not, it is dead anyway and keeping it is just inviting more trouble, so remove and discard it after doing a little autopsy (verticillium makes dark, almost black streaks in the wood, for example). Be sure to sanitize your pruners afterward (e.g., wipe the cutters with 70% isopropyl alcohol).
Thanks for the response. With the dieback, do I suppose to cut it off. Does die back spread if you dont remove? Some branches just have freeze burn on them but seem to be alive because new buds are showing up. I don't think its verticillium. The tree was healthy when it was purchased it and it was taken care off. The frost in April was just so random. Currently the tree is recoving but the some branches are not showing signs of new growth. Do I wait until August to see if new growth may happen before its necessary to prune. I know the damage is done but need advice how to proceed.
 

0soyoung

Imperial Masterpiece
Messages
5,438
Reaction score
8,216
Location
Anacortes, WA (AHS heat zone 1)
USDA Zone
8b
I know the damage is done but need advice how to proceed.
The bark on the branch starts turning black-ish indicates the cambium beneath the bark is dying. It will just become a lifeless, budless branch. BUT, if the black-ishness continues to spread and does not stop at a node, a pathogen or toxin is indicated. You should prune that black-ish part plus a little bit so as to remove the pathogen/toxin from getting to the rest of the tree.
Otherwise, wait and see.

No buds on a branch mean it is already dead. If you can see anything that might be a bud, wait and see. It will become obvious. A dead twig or even a dead branch is simply unattractive.

In general, wait and see - it will become obvious.
 

ysrgrathe

Shohin
Messages
366
Reaction score
426
Location
CA
USDA Zone
9b
Did you remove the damaged leaves? How the dead leaves appear is a strong diagnostic sign.

Note that a tree with pseudomonas will be damaged/killed by a frost that wouldn't damage a healthy tree. Just saying that shishi doesn't mind light freezes isn't the whole truth.
 

Similar threads


Top Bottom