Is this wilt? Do I cut them down right away? I have three small white oaks on my property planted from seedlings and they all have it. Red and bur oak growing amongst them are not showing any of this.
Oak Wilt?
- Thread starter svk
- Start date
Help Support Arborist Forum:
flyboy553
Oakaholic
From what I understand of oak wilt, it is far more prominent in red oak than white or burr oak. Very rare for white oak to be infected here in central MN, but a LOT of red oak have it. In fact, have not seen it at all in any white oak. Although it can get it according to the state of MN AG department.
Ted
Ted
Torch68
ArboristSite Operative
First thing to do is positively identify the problem, get in touch with your state forester to find out what it is. An emailed photo to them is easy enough. The last thing you do is start to cut them down without knowing what you are dealing with.
Those look distinctly to be the leaves of Bur Oak, not White Oak... and the spots on them appear to be Bur Oak Blight (BOB), not Oak Wilt.
Here's a link to Bur Oak Blight...
http://www.myminnesotawoods.umn.edu/2010/09/bur-oak-blight-bob-in-minnesota/
BOB has been devastating the Bur Oak here in Iowa for some time now.
*
Here's a link to Bur Oak Blight...
http://www.myminnesotawoods.umn.edu/2010/09/bur-oak-blight-bob-in-minnesota/
BOB has been devastating the Bur Oak here in Iowa for some time now.
*
Pretty sure this is a white as the bur have the pronounced bell in the leaves. Here's a better shot of leaf silhouette.
teds right again! shame on you for being so amnD good!!! lol
From what I understand, oak wilt looks more like a powder like fungus that grows on the trunks.
I've seen trees with this fungus on the trunk and they look fine for a long time and then suddenly they die over night.
What I see in the picture is common around here and nothing to worry about.
It looks a lot like water drops that were exposed to the sun and it creates a magnifying effect that burns the leaf.
I've seen trees with this fungus on the trunk and they look fine for a long time and then suddenly they die over night.
What I see in the picture is common around here and nothing to worry about.
It looks a lot like water drops that were exposed to the sun and it creates a magnifying effect that burns the leaf.
Yep, the second shot is White Oak... but those don't look anything like the leaves in the first shot.
Was the first pic of some lower, understory branches??
*
Was the first pic of some lower, understory branches??
*
Yes, and I apologize for it being somewhat dark.
Lowest branches are completely defoliated.
So do we have a consensus or should I get a forester involved?
Update: Checked with a DNR forester that I knew from way back. He's thinking its anthracnose but had asked for more information which I sent to him but haven't heard back yet.
Iska3
Addicted to ArboristSite
I see a lot of that on the Maples and Basswood more than the oaks. It could be that this wet spring caused it to show up more on the oaks. Ted is right about the white oaks, I’ve never seen any oak wilt on any of the white oaks and the oak wilt started on the red oaks back around 1992 in our area. It started on the tips of the limbs and worked it way down the heart of the trees. Once the spores started, the other trees were affected through the ground. Most of the time the oak tree will be affected four years or more before you see anything wrong with the tree. It will be interesting to see what you find out.
I'm bringing in a few leaves next week to him just to be sure. Hope so as I don't want to cut them down!
Confirmed as anthracnose. Phew I really didn't want to cut them.
My understanding is that it's basically like the leaves absorbed too much water caused by an overly wet weather and then got burned by the sun. And it takes care of itself.
Iska3
Addicted to ArboristSite
It seems like a lot of the anthracnose is found on the stree related trees. Years of standing water, spray for week killer on the lawns, too dry, and believe it or not, even compaction from your ridding mower. We see it in our woods because we never do much with that part of the woods. There is a standing joke around here; the city people come up here, buy a wooded lot, build a big home in the middle of the woods and 5 years later we get to cut down their oaks around the house because they are starting to die from stress and compaction by man.
Years ago we never saw this because the farmer heated with wood and never left dead trees rot in the pasture or his woods; now most never cut the tops or the soft woods and let that rot. Like I wrote, I've seen this in a lot of different trees and it does and will kill those trees in due time. I saw it happened in the Birch, soon it happen in the Oaks, Bass and now in the Maples. It might take 10 years or more but the tree will slowely die because the .twolined chestnut borer will move in. What they don't tell you is once the tree in stressed and weekened, the twolined chestnut borer moves in.. Read the second link.. We are a mushroom hunting family so we learn to look for infected trees because the mushroom grows underground and when the tree starts to die, the mushroom will grow on the tree or under it to flower and drop it's spores. Read about the Honey Mushroom, Chicken of the Woods and the Chantertelle Mushrooms.
They have been doing a 25 year study on some of our trees so I see a lot of this.. I can see where parts of our woods were never cleared in 40 years and the mold and fungus has taken over.. The twolined chestnut borer is nasty, not only does it kill the mature tree but the fungus must attack the new saplings so we never see new oaks growing like we should.
svk, read the second link...
Keep an eye one those trees because it takes many years to replace one of that size.
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/anthracnose/
http://www.na.fs.fed.us/spfo/pubs/fidls/oakdecline/oakdecline.htm
Years ago we never saw this because the farmer heated with wood and never left dead trees rot in the pasture or his woods; now most never cut the tops or the soft woods and let that rot. Like I wrote, I've seen this in a lot of different trees and it does and will kill those trees in due time. I saw it happened in the Birch, soon it happen in the Oaks, Bass and now in the Maples. It might take 10 years or more but the tree will slowely die because the .twolined chestnut borer will move in. What they don't tell you is once the tree in stressed and weekened, the twolined chestnut borer moves in.. Read the second link.. We are a mushroom hunting family so we learn to look for infected trees because the mushroom grows underground and when the tree starts to die, the mushroom will grow on the tree or under it to flower and drop it's spores. Read about the Honey Mushroom, Chicken of the Woods and the Chantertelle Mushrooms.
They have been doing a 25 year study on some of our trees so I see a lot of this.. I can see where parts of our woods were never cleared in 40 years and the mold and fungus has taken over.. The twolined chestnut borer is nasty, not only does it kill the mature tree but the fungus must attack the new saplings so we never see new oaks growing like we should.
svk, read the second link...
Keep an eye one those trees because it takes many years to replace one of that size.
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/anthracnose/
http://www.na.fs.fed.us/spfo/pubs/fidls/oakdecline/oakdecline.htm
