Oak wilt in Chestnut Oaks in Maryland

Pacafist

Member
Hey guys, so I'm not too familiar with Oak wilt, as I don't come across it that often in pennsylvania. I know that the White Oak Family is not as susceptible to the fungus as red oaks, and if they are exposed, they tend to die back much more gradually, starting with tip die back and eventually taking leads at a time, instead of taking the whole tree out within a season, like with Red Oaks.

My parents live in Maryland near the bay, and they've had a few tree services come out and look at the one oak tree in particular that I knew was going to eventually die. I figured the decline had to do with root disturbance from when they got the structure of their house worked on. The decline has been tip die back, starting with one or two specific leads, that have had to be pruned out during the course of the past three years. The tree is going to die, there is no question of that, but there are dozens of chestnut oaks in my parents yard.

One Tree service stated that the tree had Oak wilt and would need to be removed asap; as well as the neighboring tree, but that eventually, if this were the cause, all of their trees would need to be removed and that fungicide treatments may be more costly over the years than just removing them altogether, (we all know how this story goes).

I personally have no experience with the disease, but being that white oaks are less susceptible to the fungus, and that there has been a lot of work done to disturb the roots of the one specific tree, I was hoping someone with more experience would be able to help me out with what to look for, and how to assess if Oak Wilt is the cause, the next time I go down (two weeks from now).

Unfortunately I am unable to get the information I would like without looking at the trees personally, so I have a few questions in particular for when I do go down:
1) Are Chestnut Oaks more susceptible than others in the white oak family.
2) What specifically in a Chestnut Oak (or just white oak I suppose) should I look for in terms of diagnosing this definitively
3) I know it is spread through beetles, but most commonly root grafts between the oaks, (within fifty feet is my understanding) is the largest cause of the spread.
4) If Oak Wilt is the cause, what would be a fair price for injections of fungicide, and/or other treatments for the soil and tree. (generalized by the area of what needs to be done I suppose)
5) any other suggestions or tips on the subject matter that I have not brought up would be amazing, I would hate to see a couple of dozen Oaks die because of this, or worse, have an improper diagnosis that would waste money and possibly cause the death of other Oaks because of the improper diagnosis.

Any thing is useful at this point besides what you can find on the internet already. Please help! Thanks all
 

ATH

Well-Known Member
Oak wilt is not a slow decline. Not that a declining tree can't get oak wilt!

I'm pretty sure Chestnut oak would be more susceptible than other white oaks. A big part of the reason that the disease doesn't spread in white oaks as much as red oaks is that the tyloses in white oak seal it off. However, Chestnut oak is unique in that it is in the white oak group but it has no tyloses. I don't know how that actually plays out in the real world though because in Ohio the Oak wilt hot spots don't overlap the native range of Chestnut oak....

I disagree that root grafts are the most common cause of spread. It isn't either/or - it is both. Beetles bring it to a new pocket. Spreading within that pocket happens via grafting (and beetles...)

If it is oak wilt, if the adjacent trees show NO sign of decline, I'd cut roots on both sides and see how they look in the growing season - unless they are OK with taking those trees anyhow, then just cut the next row out and be done with it.

I'd run from the guys who say you need to cut ASAP. You need to cut before April... If they are saying it needs done now, I'd be more suspicious that means they either want to cut before you have a chance to price shop or that they need to make a loan payment this week...

I'd also run from somebody diagnosing oak wilt without lab samples unless you are in the middle of a heavily infested area. This time of year, you are left with some staining in the twigs and pressure pads (fungal mat) under the bark. But on a declining/nearly dead oak, there are other fungi that can look similar. Even lab diagnostic can be tough this time of year because the fungus is not active and traditionally, they grow spores in a dish. I'd send samples out for DNA testing at Research Associates Laboratory
 

Pacafist

Member
Thank you guys so much for the input. I thought it was sketchy that someone would suggest all of that. I honestly didn't even think about having a lab sample done, but it makes total sense to me that, with the area not being heavily infested, a lab sample should be done; especially if they want to take multiple trees out because of it.
I've been keeping an eye on the trees whenever I get the chance to go home, and, other than typical deadwood that just needs trimming, the other trees seem in fairly good health. I believe there is one that may be starting to decay but that could've been caused by a number of reasons, and it is far enough away where I wouldn't consider it at risk, especially given the fact that the oaks in between them have no sign of decline.

I personally think that a lot of the decline on this tree in particular is due to the fact that its root structure was damaged when the house underwent structural reconstruction. But I wanted to get some other opinions as I have no experience with Oak Wilt.
 

Pacafist

Member
Oak wilt is not a slow decline. Not that a declining tree can't get oak wilt!

I'm pretty sure Chestnut oak would be more susceptible than other white oaks. A big part of the reason that the disease doesn't spread in white oaks as much as red oaks is that the tyloses in white oak seal it off. However, Chestnut oak is unique in that it is in the white oak group but it has no tyloses. I don't know how that actually plays out in the real world though because in Ohio the Oak wilt hot spots don't overlap the native range of Chestnut oak....

I disagree that root grafts are the most common cause of spread. It isn't either/or - it is both. Beetles bring it to a new pocket. Spreading within that pocket happens via grafting (and beetles...)

If it is oak wilt, if the adjacent trees show NO sign of decline, I'd cut roots on both sides and see how they look in the growing season - unless they are OK with taking those trees anyhow, then just cut the next row out and be done with it.

I'd run from the guys who say you need to cut ASAP. You need to cut before April... If they are saying it needs done now, I'd be more suspicious that means they either want to cut before you have a chance to price shop or that they need to make a loan payment this week...

I'd also run from somebody diagnosing oak wilt without lab samples unless you are in the middle of a heavily infested area. This time of year, you are left with some staining in the twigs and pressure pads (fungal mat) under the bark. But on a declining/nearly dead oak, there are other fungi that can look similar. Even lab diagnostic can be tough this time of year because the fungus is not active and traditionally, they grow spores in a dish. I'd send samples out for DNA testing at Research Associates Laboratory
I did read that there were certain white oaks that were more susceptible to oak wilt precisely for the reason you stated, but I wasn't sure if chestnut oaks were among them.

The other really sketchy thing that got my wheels turning about the whole thing was that the guy kept referring to them as hickory oaks; and they are most definitely Chestnut Oaks. If he can't properly identify the type of oak, what are his credentials for identifying a catastrophic fungi like oak wilt? I could see maybe confusing it with a swamp oak....but come on man.

Referring to making cuts before April, I was aware of that, but when would be the best time to take a sample for diagnostics? This is more curiosity at this point.
 
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ATH

Well-Known Member
Cultured samples are best during growing season. And you need to get FRESH samples to the lab. Even cutting them in the morning and leaving them in your hot truck for the day then shipping at end of day can spoil them. You want a "transitioning" part of the tree where some looks live and some is near death. Good samples make a huge difference in any diagnostics, but are particularly important with oak wilt as it occupies a pretty narrow niche...soon after it has done its deed, something else is moving in and can displace the fungus.

You can sample for DNA any time. Find a piece you suspect to have been infected and send it in whenever. The evidence remains. The challenge there is if it is not oak wilt, you still don't know what it is. If the lab is culturing the sample, they'll tell you what they grew as where DNA is a yes/no answer (at least for now...).
 

Amber Jones

New Member
I did read that there were certain white oaks that were more susceptible to oak wilt precisely for the reason you stated, but I wasn't sure if chestnut oaks were among them.

The other really sketchy thing that got my wheels turning about the whole thing was that the guy kept referring to them as hickory oaks; and they are most definitely Chestnut Oaks. If he can't properly identify the type of oak, what are his credentials for identifying a catastrophic fungi like oak wilt? I could see maybe confusing it with a swamp oak....but come on man.

Referring to making cuts before April, I was aware of that, but when would be the best time to take a sample for diagnostics? This is more curiosity at this point.
I think chestnuts are related to hickory
 

Amber Jones

New Member
Thank you guys so much for the input. I thought it was sketchy that someone would suggest all of that. I honestly didn't even think about having a lab sample done, but it makes total sense to me that, with the area not being heavily infested, a lab sample should be done; especially if they want to take multiple trees out because of it.
I've been keeping an eye on the trees whenever I get the chance to go home, and, other than typical deadwood that just needs trimming, the other trees seem in fairly good health. I believe there is one that may be starting to decay but that could've been caused by a number of reasons, and it is far enough away where I wouldn't consider it at risk, especially given the fact that the oaks in between them have no sign of decline.

I personally think that a lot of the decline on this tree in particular is due to the fact that its root structure was damaged when the house underwent structural reconstruction. But I wanted to get some other opinions as I have no experience with Oak Wilt.
I think chestnuts are related to hickory
Sorry not awake, chestnuts are in the beech family and hickory be is related to Walnut my bad
 

ATH

Well-Known Member
Oh yeah...forgot about that change. I learned it as Q. prinus and don't see it around here so not used to it. That is a strange change...I get it when the change a family or genus - but why change a specific epithet? It doesn't even grow in Montana:endesacuerdo:
 
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