Oak wilt disease documented in northeastern Massachusetts?

[moss]

I've got a customer with one red oak after another dying quickly. The first 3 started 3 years ago and were stone dead within 6 months. 4 more are now either totally dead (fall foliage still attached on one) or showing the beginning of upper crown die-off. What the dead or dying trees have in common is they are in seasonally wet woods (adjacent to their back yard). I've noticed the same thing happening in two adjacent properties that share the same wet woods. A tall/mature white oak in the midst of the red oaks is looking good. Red maples, white pines and black birch mixed in with the red oaks look good.

When the first tree died I sent branch/twig samples to UMass Extension Service for testing. Don't have the report in front of me but they found a twig fungus that they think fired up as a result of the exceptionally wet summer at the time. Problem now is those conditions don't exist and red oaks are continuing to die rapidly. None of them have been defoliated by a caterpillars of any species in the last 5 years. I did "solar panel" pruning in the crowns of 3 red oaks five years ago, small 3" (a few 4") or less pruning cuts during dormant season. One of those died in Fall 2024 but whatever is killing the trees doesn't care whether they've been touched by a saw or not. A second oak that I'd pruned is now showing the beginnings of crown die-back.

I haven't looked for dark stripes in the branch wood yet and I haven't examined leaves for the described "from the margins inward" fail progression. I will continue to monitor.

Anyone else in Mass. or southern New Hampshire seeing this kind of progressive red oak family tree death in wet forest habitat?

Thanks!
-AJ

 

[Stumpsprouts]

I've got a customer with one red oak after another dying quickly. The first 3 started 3 years ago and were stone dead within 6 months. 4 more are now either totally dead (fall foliage still attached on one) or showing the beginning of upper crown die-off. What the dead or dying trees have in common is they are in seasonally wet woods (adjacent to their back yard). I've noticed the same thing happening in two adjacent properties that share the same wet woods. A tall/mature white oak in the midst of the red oaks is looking good. Red maples, white pines and black birch mixed in with the red oaks look good.

When the first tree died I sent branch/twig samples to UMass Extension Service for testing. Don't have the report in front of me but they found a twig fungus that they think fired up as a result of the exceptionally wet summer at the time. Problem now is those conditions don't exist and red oaks are continuing to die rapidly. None of them have been defoliated by a caterpillars of any species in the last 5 years. I did "solar panel" pruning in the crowns of 3 red oaks five years ago, small 3" (a few 4") or less pruning cuts during dormant season. One of those died in Fall 2024 but whatever is killing the trees doesn't care whether they've been touched by a saw or not. A second oak that I'd pruned is now showing the beginnings of crown die-back.

I haven't looked for dark stripes in the branch wood yet and I haven't examined leaves for the described "from the margins inward" fail progression. I will continue to monitor.

Anyone else in Mass. or southern New Hampshire seeing this kind of progressive red oak family tree death in wet forest habitat?

Thanks!
-AJ

Test soil for phytophthora?

 

[Bendroctanus]

What do the leaves look like? Is it the whole tree dying at once or different sections/columns? Any types of mushrooms or fungal fruiting bodies anywhere?

Personally, if I had any suspicion, I would reserve all cutting for the dormant season.

 

[ATH]

I'd try a couple of different tests for Oak wilt specifically.

Note: unless its a "perfect" sample, oak wilt can be hard to find with traditional lab culture - but that's still the most definitive test if they get a positive. If you can either hand deliver or next day ship the samples, that's the best bet. Let the lab know they are coming. UMASS may not be familiar with the process if they haven't been doing Oak Wilt testing???

You can also use DNA testing. Research Associates Labratory - it's only $20 per sample. https://www.vetdna.com/application/forms/horticulturesubmissionform.pdf Some university/extension labs are also using DNA testing.

Is it there???

USFS has an Oak Wilt "Story map" that outlines the threat and includes all of the NE: https://www.fs.usda.gov/inside-fs/d...ps-navigate-oak-wilt-disease-threat-northeast

That leads here: https://usfs.maps.arcgis.com/apps/MapSeries/index.html?appid=9aec8460770d46aa9d073ae7ec2c783e - if you click on the "Distribution and Severity" tab it shows where it is and where they project it will be severe.

It has been showing up in parts of Ohio where it had not traditionally been. There are at least 2 counties where I have personally confirmed infestations (as have others with public agencies at other locations in those same counties) that are not on the map showing infestations...so that is not a conclusive data set.

The ONLY thing that makes me second guess Oak wilt just based on one post of information is the wet woods...it seems like it shows up more in sandy soils as opposed to the heavy soils/wet woods.

 

[ATH]

PS: If you are looking for a good place to learn about Oak Wilt, a member of Ohio ISA put together a nice program (I think it may have been part of a Masters degree program?):

Oak Wilt

Several factors and circumstances favor Oak wilt infection, and the Ohio Chapter International Society of Arboriculture (ISA) offers a self-paced virtual training course for ISA Certified Arborists to learn more.

ohiochapterisa.org

There is a cost, but he put a lot of good practical information in there. Only downside: I really only have time to do things like this later at night...and he has a very calm voice (you can see where this is going, right?) There were parts I had to watch again after dozing off! Not that its boring...that's all on me being too tired.

 

[Rusticus]

I'll echo the DNA testing. It's not sensitive to the timing and temperature like the culture tests and the results are quick. I typically send in three of the best samples I can. It's easy to get a false negative due to the irregularities is the final growth within in the canopy. Even with three samples, I've always received at least one of them back as negative in the last 2 dozen tests.

 

[moss]

Test soil for phytophthora?

According to UMass Extension Service the Phytophthora species that attacks oak roots is not in eastern Massachusetts but... everything's on the table.
-AJ

 

[moss]

I'll echo the DNA testing. It's not sensitive to the timing and temperature like the culture tests and the results are quick. I typically send in three of the best samples I can. It's easy to get a false negative due to the irregularities is the final growth within in the canopy. Even with three samples, I've always received at least one of them back as negative in the last 2 dozen tests.

Yep, makes sense. I sent some good samples on the original testing 3 years ago and the lab mentioned that it was very challenging figuring out what was going on.
-AJ

 

[moss]

PS: If you are looking for a good place to learn about Oak Wilt, a member of Ohio ISA put together a nice program (I think it may have been part of a Masters degree program?):

Oak Wilt

Several factors and circumstances favor Oak wilt infection, and the Ohio Chapter International Society of Arboriculture (ISA) offers a self-paced virtual training course for ISA Certified Arborists to learn more.

ohiochapterisa.org

There is a cost, but he put a lot of good practical information in there. Only downside: I really only have time to do things like this later at night...and he has a very calm voice (you can see where this is going, right?) There were parts I had to watch again after dozing off! Not that its boring...that's all on me being too tired.

Thank you

 

[moss]

I'd try a couple of different tests for Oak wilt specifically.

Note: unless its a "perfect" sample, oak wilt can be hard to find with traditional lab culture - but that's still the most definitive test if they get a positive. If you can either hand deliver or next day ship the samples, that's the best bet. Let the lab know they are coming. UMASS may not be familiar with the process if they haven't been doing Oak Wilt testing???

You can also use DNA testing. Research Associates Labratory - it's only $20 per sample. https://www.vetdna.com/application/forms/horticulturesubmissionform.pdf Some university/extension labs are also using DNA testing.

Is it there???

USFS has an Oak Wilt "Story map" that outlines the threat and includes all of the NE: https://www.fs.usda.gov/inside-fs/d...ps-navigate-oak-wilt-disease-threat-northeast

That leads here: https://usfs.maps.arcgis.com/apps/MapSeries/index.html?appid=9aec8460770d46aa9d073ae7ec2c783e - if you click on the "Distribution and Severity" tab it shows where it is and where they project it will be severe.

It has been showing up in parts of Ohio where it had not traditionally been. There are at least 2 counties where I have personally confirmed infestations (as have others with public agencies at other locations in those same counties) that are not on the map showing infestations...so that is not a conclusive data set.

The ONLY thing that makes me second guess Oak wilt just based on one post of information is the wet woods...it seems like it shows up more in sandy soils as opposed to the heavy soils/wet woods.

Superb interactive mapping. Yes, this all makes sense. Oak Wilt will be pretty much everywhere there are red oak family trees in the Northeast. And it is a dominant oak family in the Northeast for sure.

So... the map shows Oak Wilt not currently reported for most of if not all of the Northeast US.

To your point about well drained sandy soils and Oak Wilt, Long Island, NY is showing as being hit hard. Being a terminal glacial moraine that entire land feature is sand, gravel and rocks ;-)

Based on what you're saying and what I've looked up I believe it's safe to rule out Oak Wilt for my customer's location northeast corner more or less in Massachusetts

Thanks everyone for the quick and useful responses, I will continue to follow up on the situation.
-AJ

 

[ATH]

...

Based on what you're saying and what I've looked up I believe it's safe to rule out Oak Wilt for my customer's location northeast corner more or less in Massachusetts
...-AJ

I'd still suggest doing a DNA test if you find anything that looks remotely like a pressure pad on the bark later this summer.