May 2022


Hello and happy spring! 

The Great Lakes Basin Forest Health Collaborative has been picking up steam this quarter. Grafting and stratification projects are underway at the Holden Arboretum outside of Cleveland, OH. And now that trees are leafing out, we’re eager to start hunting for potentially resistant ash and beech all across the Great Lakes basin — we’ll be on the lookout for your reports, too. 

As always, please share this email with anyone you think may be interested in joining our forest health community!

-Rachel Kappler

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The Latest

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The latest batch of beech grafted at Holden.

We’re grafting

We held a grafting training workshop at Holden, and have grafted trees for beech leaf disease research at the gardens. These grafted trees let us clone potentially resistant trees from the forest for further study. Read more about our grafting progress here. We held our first ash grafting training online for one of our partners.

Also, the USFS N. Research Station in Delaware, OH creates lingering ash replicates for resistance assessment tests each year. This year they grafted from eight new lingering ash.

We’re stratifying

Also at the Holden Arboretum, researchers started their first batch of eastern hemlock seeds — seeds from 16 different locations — which are about to be removed from cold stratification. These seeds need three months in cold, moist conditions before they’ll germinate and will be used for future research into HWA resistance.

We got the beech

We use the TreeSnap app to collect observations of our target trees, eastern hemlock, ash species, and American beech — but until now, beech was only a write-in option. We’re pleased to report TreeSnap will be adding beech to its interface this June for even easier reporting. Visit to get started.

Ash & EAB updates

In OH, MI, northern IL, western PA, and sections of NY, partners are working on surveying for lingering ash. In other areas, EAB is still progressing to various counties or has not caused enough damage for us to locate lingering ash. WI has noted their recommendations for landowners and updated their EAB detection map. The national map of EAB detections is continuously updated here.

Eastern hemlock updates

The Virginia Tech website has updated their HWA distribution maps and HWA predator database, and houses other pertinent HWA information. 

Have an update to share in the next GLB FHC newsletter? Email us.

Call for proposals: Conserving and restoring forests

"The National Fish and Wildlife Foundation (NFWF) ... is pleased to announce the launch of the America the Beautiful Challenge (ATBC) 2022 Request for Proposals (RFP). The ATBC vision is to streamline grant funding opportunities for new voluntary conservation and restoration projects around the United States. In year one of the ATBC approximately $85 million will be awarded in nationwide funding to advance the America the Beautiful Initiative and its goals to connect and restore the lands, waters, and wildlife upon which we all depend." Read the Request for Proposals here.


Get Involved: Hunt for Trees

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In the upcoming quarter, the number one thing we need from our partners and allies is: trees. Mid-May to August is a great time to look for ash and beech that are lingering in otherwise infected areas and may be resistant. It’s an enormous help to us to know where these trees are located.

Report tree sightings with the TreeSnap app or by emailing them to us directly at Training workshops to help with tree ID, using the TreeSnap app, and more are available online or in-person at the Holden Arboretum, with more to come in the future at other partner locations across the Great Lakes — contact us today to sign up, or to set one up for your organization.

Upcoming lingering ash workshops

Blue Week Event: Lingering Ash Training

Host: The Nature Conservancy in Ohio, a Green Ribbon Initiative Partner

When: Sunday, May 22, 4-6 pm

Where: Metroparks Hall at Wildwood Metropark, 5100 Central Ave, Toledo, OH 43615

Register here for the Toledo workshop

How to Identify and Report Lingering Ash trees

Host: MI DNR Parks & Recreation

When: Thursday, June 9th

Time: 6 – 8 pm

Where: Hickory shelter at Maybury State Park

Address: 49601 Eight Mile Rd., Northville, MI

Register: email

How to Identify and Report Lingering Ash trees

Host: MI DNR Parks & Recreation

When: Friday, June 10th

Time: 6 – 8 pm

Where: Picknick Shelter at P.J. Hoffmaster State Park

Address: 6585 Lake Harbor Rd, Norton Shores, MI 49441

Register: email

How to Identify and Report Lingering Ash trees

Host: Holden Forests & Gardens

When: Wednesday, June 15, 2-4pm

Where: Visitor Center at The Holden Arboretum, 9550 Sperry, Kirtland, OH 44094

Register here for in-person training at Holden

Online option: Thursday, June 16th, 10 am-12pm, Zoom 

Register here for online lingering ash training

How To: Identify and Report Lingering Ash Trees

Host: The Dawes Arboretum

When: Saturday, June 18, 10 am-12 pm

Where: The Dawes Arboretum, 7770 Jacksontown Rd, Newark, OH 43056

Register here for the workshop at Dawes


How to report beech leaf disease

We are also seeking reports of beech leaf disease symptoms spotted in new areas. Check the map above to see if your county has recorded BLD. Symptoms include dark stripes between veins, curling or other distortions to shape, and in extreme cases withering, dry, or yellowing leaves. 

If you see these symptoms, report them with the Tree Health Survey app, available on iPhone and Android. And be sure to check out the excellent Tree Health Survey app user manual that our partner, Cleveland Metroparks, put together.

Research Roundup


Figure 1A from Held et al. 2022, below.

  • Ash successfully cloned in the lab. Researchers from the University of Georgia and the U.S. Forest Service used a lab technique called somatic embryogenesis to clone lingering ash from non-reproductive cells collected from the field. [Merkle et al. 2022 New Forests.]

  • Interesting fungi live in ash galleries. A diverse community of fungi move into EAB galleries, notably including fungi that can accelerate tree decay and fungi that may be a candidate for biocontrol of the borers. [Held et al. 2022. Fungal Biology.]

  • Beech leaf disease usurps beech bark disease. In Great Lakes forests, beech leaf disease and scale are now dominant threats; beech bark disease is still present, but occurrence is now low. [Reed et al. 2022. Forest Ecology and Management.]

  • Hemlock woolly adelgids don’t like the rain. Massachusetts researchers looked at both observational field data and results from experimental rain simulations and found more rainfall leads to declines in adelgid populations. The trend is likely due to rainfall facilitating spread of fungal entomopathogens. [Chandler et al. 2021. Environmental Entomology.]

  • When it comes to seed collection, how local is local? Researchers from the Forest Service developed a map of 245 seed-collection zones (to describe the origins of seeds) for 37 eastern U.S. states based on hardiness zones and ecoregions. [Pike et al. 2020. Journal of Forestry.]

Have new research to share in the next GLB FHC newsletter? Email us.

Trees in the News

The Great Lakes Basin Forest Health Collaborative is an initiative co-sponsored by Holden Forests & Gardens and the USDA Forest Service, funded through the Great Lakes Restoration Initiative

USDA is an equal opportunity provider, employer, and lender.

MISSION: Holden Forests & Gardens connects people with the wonder, beauty, and

value of trees and plants, to inspire action for healthy communities

VISION: All communities transformed into vibrant places where trees, plants, and people thrive

Copyright © 2022. All Rights Reserved. "Holden Forests and Gardens" and the related logo is a trademark owned by The Holden Arboretum.