A snake bark maple (sorry, not sure which species, but if it's important I can dive into my reference books and find out) has an area of dead bark extending about half way around the tree and for a vertical distance of about a foot.

The tree is about 10 years old, trunk diameter about 4 inches (girth about 12inches), height about 12ft. It's in cold clay, gets waterlogged for a few hours at a time about half a dozen times a year, and is surrounded by various other small trees and large bushes. Until now, it's been growing healthily, and has flowered profusely for the last three years.

There is no sign of pest on the dead bark area, or any sign of weeping, visible fungus or anything else. It looks like the sort of damage you get when a couple of branches rub together, though this is obviously not the case here. One twiglet growing from the damaged area is dead, but the rest of the tree, both above and below the damaged area, seems fine.

Any ideas? I've googled but not found anything - most acer disease hits refer specifically to A palmatum, and adding 'snake bark' gets the sales hits.

"kay" wrote in message
...

A snake bark maple (sorry, not sure which species, but if it's important
I can dive into my reference books and find out) has an area of dead
bark extending about half way around the tree and for a vertical
distance of about a foot.

The tree is about 10 years old, trunk diameter about 4 inches (girth
about 12inches), height about 12ft. It's in cold clay, gets waterlogged
for a few hours at a time about half a dozen times a year, and is
surrounded by various other small trees and large bushes. Until now,
it's been growing healthily, and has flowered profusely for the last
three years.

There is no sign of pest on the dead bark area, or any sign of weeping,
visible fungus or anything else. It looks like the sort of damage you
get when a couple of branches rub together, though this is obviously not
the case here. One twiglet growing from the damaged area is dead, but
the rest of the tree, both above and below the damaged area, seems
fine.

Any ideas? I've googled but not found anything - most acer disease hits
refer specifically to A palmatum, and adding 'snake bark' gets the sales
hits.

Can you lift up any of the bark to see if there is anything underneath
(animal or fungal)? How long has it been showing this damage? If the
damaged area moved all the way round the trunk and is not just superficial,
then could it ringbark the tree and kill everything above it?

If there is a dead twig growing out of the damaged area is it cause or
effect?

Sorry - more questions than answers. If you are a member of the RHS they
can identify pests and diseases if you send them a piece of the damaged
material
(http://www.rhs.org.uk/Gardening/Help...n-and-examina).

--

Jeff

Having had another look, I realise that one of the branches above the damaged area has damaged leaves - they look all scrumpled up, like aphid damage on viburnums. It's too high to get a close up look.

On 05/21/2010 04:03 PM, kay wrote:
A snake bark maple (sorry, not sure which species, but if it's important
I can dive into my reference books and find out) has an area of dead
bark extending about half way around the tree and for a vertical
distance of about a foot.


Hello Kay,

If the area of dead bark hasn't been mechanically damaged (like chewed
by a rabbit or a deer) it's likely caused by a pseudomonas syringae
infection. These are very common with all snakebarks (and many other
Acers) and are particularly common in the sort of circumstances you
describe (standing water), and with a cold, wet winter or spring.

Here's a wikipedia link on same, although the picture is not
particularly useful as it shows long healed damage.

http://en.wikipedia.org/wiki/Pseudomonas_syringae

Pseudomonas are the bane of maple growers in our climate, you are not
alone. The good news is that your tree will likely recover, and in
time, if it isn't reinfected, the wound will heal. Some snakebarks, A.
rufinerve in particular, are very good at healing. (From mechanical
damage too).

If you want to find more information, you should post a picture of the
bark with your question to the maple forum:

http://www.ubcbotanicalgarden.org/fo...isplay.php?f=9

There is a good thread which discusses the many problems associated with
maple bark he

http://www.ubcbotanicalgarden.org/fo...ead.php?t=8751

-E

Many thanks for the info. I was hoping you'd answer!

Mine differs from that pic in that the damaged bark is entirely smooth. It wouldn't look out of place on a young sycamore (it's just not right for a green and white snake-bark).

Mine looks like what is being referred to on that forum as 'tight bark'. It seems to be a largely US forum - is that diagnosis likely in the UK? ... oops - I've just googled, and seen your response of May 2006 to a similar question!

Could Verticillium wilt cause bark discolouration?

I think I'm resigned to losing the tree, which is a great shame since I grew it from seed. I'll cut out the dead branch and hope it keeps growing long enough to ripen this year's seed, then I can at lest keep it alive in spirit ;-)

The bark is still firmly attached, but I could possibly take a knife to it

Don't know. Not long. I was certainly admiring the bark within the last month, so it wasn't showing anything then.
[/quote]

If the
damaged area moved all the way round the trunk and is not just superficial,
then could it ringbark the tree and kill everything above it?

If there is a dead twig growing out of the damaged area is it cause or
effect?
[/quote]

Yes,, the damage looks as if it foes have the capacity to kill the whole tree. As to the dead twig, no idea as to cause or effect, but I have now spotted a dead branch above, which looks definitely like a result of whatever is causing the bark discoloration.

"kay" wrote in message
...

'Emery Davis[_3_ Wrote:
;887994']

If the area of dead bark hasn't been mechanically damaged (like chewed
by a rabbit or a deer) it's likely caused by a pseudomonas syringae
infection. These are very common with all snakebarks (and many other
Acers) and are particularly common in the sort of circumstances you
describe (standing water), and with a cold, wet winter or spring.

Here's a wikipedia link on same, although the picture is not
particularly useful as it shows long healed damage.

'Pseudomonas syringae - Wikipedia, the free encyclopedia'
(http://tinyurl.com/3ymxsg2)



Many thanks for the info. I was hoping you'd answer!

Mine differs from that pic in that the damaged bark is entirely smooth.
It wouldn't look out of place on a young sycamore (it's just not right
for a green and white snake-bark).


If you want to find more information, you should post a picture of the
bark with your question to the maple forum:

'General Maple Discussion - UBC Botanical Garden Forums'
(http://tinyurl.com/2bv7pgc)

There is a good thread which discusses the many problems associated
with
maple bark he

'Japanese Maple Bark Related Issues - UBC Botanical Garden Forums'
(http://tinyurl.com/2g7n987)

-E

Mine looks like what is being referred to on that forum as 'tight bark'.
It seems to be a largely US forum - is that diagnosis likely in the UK?
.. oops - I've just googled, and seen your response of May 2006 to a
similar question!

Could Verticillium wilt cause bark discolouration?

I think I'm resigned to losing the tree, which is a great shame since I
grew it from seed. I'll cut out the dead branch and hope it keeps
growing long enough to ripen this year's seed, then I can at lest keep
it alive in spirit ;-)

If you are going to do something drastic anyway, I wonder if there is any
chance that removing the dead (is it dead?) piece of bark plus another
couple of centimetres around all sides would stop the damage spreading. If
there are no other signs of this damage anywhere else on the tree, then
maybe it is completely localised, and excision may stop it in its tracks.

--

Jeff

At its widest, it's about half way round the trunk where the trunk is only 6in girth. Another couple of cm both sides would get close to completely ringing the trunk ;-)

It's a thought, though. I'll investigate a bit further.

On 05/22/2010 10:13 PM, kay wrote:
'Emery Davis[_3_ Wrote:
;887994']
[]
'Pseudomonas syringae - Wikipedia, the free encyclopedia'
(http://tinyurl.com/3ymxsg2)



Many thanks for the info. I was hoping you'd answer!


You're welcome! Glad to help when I can.

Mine differs from that pic in that the damaged bark is entirely smooth.
It wouldn't look out of place on a young sycamore (it's just not right
for a green and white snake-bark).


That sounds exactly like a dried/finished pseudomonas infection. If
there's a little black around the edge anywhere it's still active. The
finer weather should finish it off, or Jeff's suggestion is a good one
(although you really only need to go a couple of millimeters into clean
bark): use a razor blade or grafting knife to cut away the edges of the
infection, making sure to sterilize the knife with bleach or alcohol
should you accidentally cut into it.

Really impossible to be sure without good pictures, of course.

[]
'Japanese Maple Bark Related Issues - UBC Botanical Garden Forums'
(http://tinyurl.com/2g7n987)

-E

Mine looks like what is being referred to on that forum as 'tight bark'.
It seems to be a largely US forum - is that diagnosis likely in the UK?
.. oops - I've just googled, and seen your response of May 2006 to a
similar question!


Heh, I can barely remember what I said last week, much less in 2006!

"Tight Bark" is a controversial subject in the maple community, because
there really isn't any hard evidence for it's existence like
identification of the pathogen. Personally I've seen similar symptoms
on some maples but can put it down to other causes, gall or sun-scald.

Not living in the US I can't of course speak to any systematic "tight
bark" infestation in liner maples, although it's certain that many
liners here are infected with verticillium and only last a few years as
a result.

Could Verticillium wilt cause bark discolouration?


It could, but it's likely not the cause. Verticillium starts with
blackening higher up stems, and moves downwards. Also it likes warmer
weather, usually showing up in summer.

Seed grown trees are less likely to get verticillium, anyway, unless you
have it in your soil.

I think I'm resigned to losing the tree, which is a great shame since I
grew it from seed. I'll cut out the dead branch and hope it keeps
growing long enough to ripen this year's seed, then I can at lest keep
it alive in spirit ;-)


I'd be less hasty, it may well recover. Unless it's only purpose is the
snaky bark, because if it does heal over that aspect will be gone on
that part of the tree.

Good luck with it, anyway.

Off to water, it's drydrydry out there!

-E