Finding New Hampshire's Magnificent Black Ash Tree

Tips for Identifying Ash

UNH Cooperative Extension manages the NH Big Tree Program in an effort to find, record and recognize our magnificent individual trees. Each county in New Hampshire maintains a list of its champion trees and Natural Resources Stewards measure the trees according to American Forest standards and guidelines. Nominations are submitted through the web site (nhbigtrees.org) and are then sent on for measuring by team volunteers.

Black Ash
The Black Ash State Champion, Hancock NH, measuring 92' tall.

A few years ago, Forester Jeremy Turner submitted a nomination for a Black Ash (Fraxinus nigra), also called swamp ash or basket ash. It is a rare tree in NH today, with no listing for Hillsborough County. I was not sure that I could identify this tree, so I was delighted to learn that Jeremy is a forester, and is in charge of managing forests for a variety of clients.  One such client is the Audubon de Pierrefeu-Willard Pond Wildlife Sanctuary near Hancock, where this Black Ash was found.

We met in July at the Willard Pond parking lot. I was even more thrilled to learn that the tree is located right along Willard Pond Road, and viewable by the public. Of course I had already driven right by the tree, as had everyone else who has been to Willard Pond. The tree is so tall that its top is lost in the high tree canopy. No leaves or twigs for clues. Jeremy recognized it from its bark. But it just looked like shaggy old bark to me - not at all like the neat diamond patterned bark of  White Ash. Jeremy manages stands of Black Ash for basket makers, who use young fast growing trees in the baskets they craft. The trunks for baskets need to be straight and 10-12 feet tall before branching to produce the long unblemished splints that are painstakingly separated by pounding.

The tall Black Ash we measured was a knobby old hollow tree; not the quality for basket makers. Using a clinometer we measured the height at 92’.  Then, using a tape measure we determined the circumference at breast height (CBH; 4.5 feet above ground) to be 59 “. The crown was oddly shaped and tricky to measure, but we figured an average crown spread of 23 feet. The scoring formula gives this tree total points of 157, making it the NH State champion!

Coincidentally, I had just stumbled onto a great new book: Bark, A Field Guide to Trees of the Northeast, by Michael Wojtech, University Press of New England, 2011, that is perfect for identifying big trees when the leaves and canopy are far beyond reach. The author explains how different barks develop, and their impacts on tree ecology. This very useful reference book has lots of photos, diagrams, and maps of each tree species range. For example, the author describes young black ash bark as “light brown to gray with soft, corky scales that can be easily rubbed off.” While mature bark is “darker gray to grayish-brown. Scales may build in thickness and become irregular and knobby-looking.” Exactly what caught Jeremy’s eye!

2018 Update

Meanwhile, since measuring this unique tree in July 2012, the Emerald Ash Borer (EAB) has arrived in NH. The first outbreak was in the Concord area in 2013.  See UNH Cooperative Extension’s website for a map of the current distribution of EAB in NH, as well as more information on EAB.

Sadly, all ash trees in NH are susceptible to EAB.  Infested ash trees are often killed in just a few years. Mountain ash is not a true ash species, so it is not affected, but NH’s Black and Green Ash trees are vulnerable, along with our much more widely spread White Ash.   These trees will be missed by basket makers, but also a host of wildlife species, hikers, and paddlers used to seeing ash in swamps, along riversides and on rich upland soils.

The loss of Black Ash trees is having its most devastating ecological effects in the Great Lakes region and Upper Midwest.  In these regions, Black Ash can be the dominant species in large forested wetlands. Based on research conducted by the US Forest Service and Michigan Technological University, millions of acres and billions of Black Ash trees are threatened by EAB: http://forest.mtu.edu/blackashwetlands/ and https://sfec.cfans.umn.edu/sites/sfec.cfans.umn.edu/files/171017.palik_black_ash.pdf.

Ash trees are easily recognized by their compound leaves and opposite branching and their abundant clumps of seeds or samaras in late summer. Look for a litter of small oar-shaped, winged seeds hanging in large bunches on trees, or scattered on the ground below. Seeds help to distinguish ash species because they are slightly different from one another. This is a helpful clue for the tall ash trees with leaves far from reach. 


White Ash vs. Green Ash Samaras

Here are two different samaras I found in my neighborhood - July 22. 2018. The round tip one is White Ash and the one with the flatter end is most likely Green Ash. With such an abundance of seeds, White Ash saplings pop up like weeds on the edge of our woods. I may be looking at the last survivors!

You can help the NH Big Tree Program update its records by looking for giant trees. To compare a tree you discover, look up the current champion, and then measure the circumference of your tree to see if it compares.  If you find one that seems bigger than those listed, please get in touch!  Use the below links to help you through the process: