Assessing damage to Autumn Blaze Maple

[KDC]

Greetings from the North Carolina piedmont.

I'm looking for help assessing damage that seems to be progressing with an Autumn Blaze Maple. I had 8 of these trees installed in September, 2009 so they've been in the ground at my house for almost three years. All 8 trees were approximately 5-to-6 inches in diameter when installed - I'm not sure how old that makes them.

This summer I have noticed that one of the trees appears decidedly less healthy than the others. The foliage just isn't as full and generally speaking it just looks weak.

I took a closer look at the tree yesterday and I'm seeing damage to the bark that I don't understand. I have attached an image to illustrate what I see. I'm seeing insect activity in the areas where the bark is cracking and revealing the inner wood. There appears to be a couple of different ants - I'm not sure what else is living in there. I don't recall seeing this bark damage last season; my impression is that it is something that is progressing rather quickly.

The only difference in this tree, compared to the other 7, that I would note is that it's bark got damaged by the installers as it was being set into the ground. The third photo from the left shows that area. All of the damaged bark in these photos are on the trunk between the ground and the first branches (about a 5 foot section). There is no noticeable damage above the first branches.

I have also attached a second photo showing a comparison in the canopy of two of the maples. The first is nice and full - the second is the tree in question. The very last photo is obviously right at the base of the tree. Note the larger cracks in the bark. Is there anything I might do to get ahead of what's happening here?

And finally, regarding the pests that are living in the areas with cracked bark: is there a particular pesticide that I might look for?

I would greatly appreciate any ideas you have.

Best regards,

Kevin

 

[sotc]

The first group of pictures looks like sun scald. The very last photo looks like a maple phytophthora. Also looks like the tree may have been planted too deep

 

[MasterBlaster]

Welcome to the TreeHouse, Kevin. I can't help you, but I'm sure someone here can.

 

[FJR]

Which directional aspect is the damage on the trunk facing? Looks like sun scald to me too. Autumn Blaze has very thin bark when immature.

 

[pantheraba]

I agree it looks to be planted too deep...no root flare.

I'd be curious to see pictures of the base of the other trees.

 

[KDC]

Willie, FJR, and Gary, Thank you all for your comments - you're all helping to lead me to understanding several aspects of my questioning. I really appreciate that! There are several observations on this thread ...

1) Sun scald: I had to go read about it. Question: what to do with all the loose, cracked bark that is peeling back in these areas? I'm getting the impression these areas might hold water and I'm not sure that is a good thing. Should I physically remove this loose, dry bark to try to keep these areas dry? Is there any sort of "topical treatment" that should be applied in these areas?

2) Phytophthora: (re first set of photos, the last photo showing the red/brown/black residue) I had to go read about it. Any recommendations of how to get ahead of this?

3) Tree Depth: What exactly are we looking for here? Just FYI - when the installer put these trees in the ground, he used all of the excess dirt to build a berm around the base of the trees. It is quite possible the depth of that excess dirt is piled up around the base of these trees. Since the trees have been in the ground for 3 years, I've been considering removing all these berms and go back to "ground level" around the tree bases. Any thoughts on this?

4) Facing direction: regarding the tree in question, the area identified as sun scald (first set of photos, first photo) is facing due east. That side of the tree is shaded by a massive pin oak. I doubt it ever receives direct sun. The area of this tree that was damaged during installation is seen in the first set of photos, third photo. This area faces due south and receives full sun beginning around noon.

5) Gary asked about pictures of the bases of the other trees that were planted at the same time ... see attached.

Lastly, I mentioned seeing insects in the bark of the tree in question. Should I treat it with an insecticide? Any recommendations?

Thanks guys!

 

[FJR]

Interesting, If the damage is due east and area is heavily shaded then it probably is not sun scald. You did mention that there was damage to that area when the tree was installed, so it could be just that.

Tree depth is a big deal, even though it seems silly. The majority of the roots are within the top 12" of the soil, and the most limited element in the urban environment is Oxygen. So if there is too much of anything (top soil, mulch, etc..) on top of the root system then the tree is going to be deficient in oxygen and have major issues with respiration. No respiration, no energy for the tree. So the goal is to remove as much soil as needed to expose the root flare and you should see some of the upper most roots in the system. Take a picture and post it up here. We can also check to see if there are any girdled roots, which are very common with Autumn Blaze. After this is done, a light layer of mulch would be ideal. Creating a healthy environment for the tree will help a lot of other issues go away.

 

[KDC]

Thank you, FJR.

As for exposing the root flare - what do you think about the last set of photos I attached? Is the root flare for trees number 2 and 5 adequate?

 

[sotc]

Yeah, they all appear too deep. Dig down till you find the first roots. These should be just below grade.
As to insecticide, probably not necessary. Trace the bark back to good tissue and paint exposed wood with some latex

 

[pantheraba]

See the info here, re: root flare:

http://treeandshrubcare.info/air-knife/common-example-images/

Your trees look like columns rising out of the ground...look at a selection of trees around you and you will start noticing root flare. Trees that grow naturally show root flare...trees that are transplanted by people often don't show any flare...as I understand it, the trees are basically suffocating (like FJR said....respiration issues...no oxygen, no energy...same for us human folk).

I am not a CA like SOTC and others but I have learned a bit from them.

 

[KDC]

Understood on the root flair business - makes perfect sense. I need one last bit of guidance in this area.

As I mentioned the installer used the excess dirt from the hole to form a berm (moat) around the trees. I just raked back some of the mulch and dirt to see how deep the root flair is. I'm finding an abundance of roots have grown into this berm and seem to be reaching for the surface.

I wanted to remove these berms anyway - to take these areas back to ground level - which seems necessary anyway to find the root flair. Exposing the root flair will require removing a lot of this dirt, which will expose a lot of roots? What about the roots being exposed - you wouldn't cut these off would you???

See attached. These berms are about 8 feet in diameter and about 6-7 inches deep/high at their crown. I have barely scratched the surface and you can see larger roots around the outside. There are also much smaller (hair-like) roots nearer the base of the tree.

Help!

Well, it looks like those stem-girdling roots do get removed ... any thoughts on this info? http://hort.ufl.edu/woody/remove-girdling-roots.shtml

 

[sotc]

I wouldn't worry about the berm as long as you open a place in part of it. Root crown looks pretty good now

 

[KDC]

I wouldn't worry about the berm as long as you open a place in part of it. Root crown looks pretty good now

Thanks, Willie. Do you see any problem with removing those surface roots?

 

[sotc]

Not if it's just a few. Pretty young and vigorous tree.

 

[Underwor]

We have had a lot of problems in Minot with this tree. Very thin foliage, die-back and eventual death. Root crowns, watering, sites all seem okay, in spite of normal variations in the city environment. I am going to look at some of them again this week, following this thread. As of now we will not be planting them on boulevards in the future. They are a great seller at the nurseries, in spite of their problems, due to the nice fall color when they do survive.
Thanks for starting the thread and giving me some additional ideas to check up on. We are never too old to learn more.

 

[pantheraba]

Thanks for checking in, Bob...this will be a good thread to watch.

 

[KDC]

Hi, guys.

Sorry to be a bother on this one. I've done what was suggested regarding exposing the root flair on all of these maples. In doing so I have found that all of these maples display roots that have grown to the surface of the berm constructed around the trees ... some more than others.

Can anyone suggest a guideline, or provide a relevant resource, about practices for removing some of these roots? For instance is there a recommendation for selectively removing some surface roots but leaving others?

Unfortunately the installer piled a lot of the excess dirt very close to some of these trees. I have to take these berms down some to fully expose the root flairs, ergo I will likely expose more roots than I already have.

The largest of these roots that are currently visible are approximately 3/4" diameter. There is one root in particular pushing an inch. I have reattached the first photo that I provided showing the roots. In most cases, the roots that have grown to the surface follow the curvature of the berm. The crown of the berm in this photo is 6-7 inches high.

Thanks!

 

[sotc]

Might wait for Guy to show up, he is helping write the BMP's I think, for root pruning. For future reference, after the first summmer is a good time to delete the berm in our weather. Those maples are notorious for putting a large amount of wood in the ground and usually near the surface

 

[treelooker]

speak of the devil--best time of year for this work is september. at that time get aggressive with widening natural/mulched areas (kill the grass now). attached are both the peer-reviewed and the workingman's version of root pruning. the standard is up for public comment (waiting to hear from some of you still!) here

http://www.tcia.org/sites/tcia.org/files/A300Part8-Drft2-V1-Roots-PubRev-07'2012.pdf

o and i'm in ApexNC, but do travel around the piedmont...