Big Tree of the Month

NH Big Tree of the Month

Tree Measuring Tale - Searching for Atlantic White Cedar

 (Chamaecyparis thyoides)

Anne Krantz, UNH Big Tree Committee, Hillsborough County Chair


The tale begins years ago when my Tree Stewards class took a field trip to the unique and rare white cedar swamp at Hackett Hill in Manchester. I remember the lacy, arborvitae-like foliage and shaggy bark on the trunks trees growing on hummocks in the swamp. At that time the land was being sold and development threatened. A happy ending was worked out by many parties and the cedar swamp is now owned by the Nature Conservancy who have preserved 600 acres, including 42 acres of cedar swamp; the Manchester Cedar Swamp Preserve that is open to the public.

After completing the Tree Steward program (now Natural Resources Stewards program), I joined the Big Tree measuring team for Hillsborough County. We received a nomination for an Atlantic white cedar tree from a resident of Goffstown that we never managed to measure before the nominator moved. The site is open space for the development so I knew that it was protected, and finding the swamp remained on my ‘to do’ list.

The winter of 2011 was cold enough for the swamp to be frozen solid, so one bitter, yet sunny January day, I ventured out alone to search for the trees.  I was happy to find the swamp right along the roadside and very happy to see that they definitely were AWC swamp/forest.  I selected the largest one near the edge that I tried to measure by myself, beginning with the circumference of the trunk. The NH Extension Big Tree program uses the American Forests system for measuring. A score is derived from three tree measurements: circumference, height and crown spread.  I had to take off my mittens to measure the trunk and my hands instantly froze!!!  Quickly on to the height using a clinometer that is calibrated to sight the tree top at 100 feet from the trunk. Getting colder - just one more measurement; the crown. The trees were so close that the crowns were tiny and it was easy to measure the crown diameter in two directions and figure the average crown spread. 

It was so cold my camera didn’t work, so I pinched off a few tips from the young shoots to photograph at home. I stuck them in a little vase of water expecting them to turn brown and die.  They didn’t - instead the foliage looked quite perky and healthy on my kitchen windowsill. So I left the twig, only to notice months later it looked as if the foliage was growing longer tips. Later it seemed that a tiny root was growing from the stem in the water!  How exciting – by summer the vase was full of roots!  I had a baby tree! Last summer I finally potted it and left it outdoors for the winter – as soon as the snow melts I will know if it survived.

Because I was so cold and rushed, I planned to come back with help to get more accurate measurements and some photos. The next 2 winters were mild and I was not interested in falling through ice into the cold swamp. But this past bitter cold winter of 2013-14 was perfect for measuring trees in a swamp.  I knew that I needed help this time, and contacted UNH Extension Forester for Hillsborough County, Jon Nute.  He was unaware of this cedar swamp just minutes away from his office, and was eager to see it.  We made plans to go measuring, but had to postpone our adventure 3 times due to bad weather and snow!!!  Finally in March Jon, team member Mike Callaghan and I were able to get the job done; lots of snow covering melting ice.  Jon pointed out that this location at the top of a hill was a perched swamp – like a tea cup with a very consistent water level.  He thought the stand look to be about 80 years old.

AWC swamps are rare in NH according to the Natural Heritage Bureau’s Natural Communities fact sheet

NH is on the northern edge of their natural range and the trees survive in isolated pockets along the coast and some inland locations south of Concord.  Nationally, the tree is true to its name and is grows along the Atlantic coastal plain from Maine to the Gulf, but not far inland. 

It is classified in the Cypress family (Cupressance) along with  CA redwoods, our native arborvitae, or northern white- cedar (Thuja occidentalis) that grows in colder climates north of Concord, and our Eastern Redcedar, or red juniper  (Juniperus Virginia), that pops up in abandoned pastures statewide.  The foliage of these three NH conifer trees is similar, but the seed pods are not: AWC produces a crumpled roundish seed cone, the northern white cedar has an elliptical cone with scales, and red cedar has blue juniper berries.   

Atlantic white cedar is a new world tree unknown in Europe and one of the first exports from the Colonies. In the 1600s ships from Jamestown returned to Europe with lumber from the shores of Virginia. It was valued for its lightweight, straight grain - good for boat building. Its excellent rot resistant qualities make it perfect for shake roofs, clapboards, fence posts and later RR ties and outdoor furniture.

Coincidentally, between my first attempt to measure the Goffstown trees and our final success in March, I came across a fascinating book The Brother Gardeners, by Andrea Wulf.  She describes the amazing story of an early American farmer and naturalist John Bartram who had a little farm on the banks Schuylkill River on the outskirts of Philadelphia where grew exotic plants.  He stumbled into the horticulture business of shipping new American plants back to the obsessed gardeners of Britain and Europe. They were eager for plants from America that they hoped would be more cold hardy that those imported from Central and South America. In 1736 he apparently included Atlantic white cedar in his ‘boxes’ of plants shipped to England where it was a hit with landscapers and botanists (plant collecting seemed to be an obsession of the wealthy).  It was popular for its narrow conical shape and became one of his most expensive plants. So he searched the coast for more and discovered them in abundance in New Jersey in the Hackensack meadowlands. He and his English partner kept the secret that it was easy to propagate from cuttings!

It is interesting that it was so popular for landscaping back then.  It is not a plant used in the nursery business today, probably because of its precise water needs – not too much and not too little.  Another problem we would have with it in landscaping is that deer are fond of it and arborvitae, and eat the bottom branches during the winter in NH.  The swamps may limit the deer damage to the swamp cedars.

Lots of others discovered the valuable NJ coastal source of lumber and Atlantic white cedar was literally slashed down. Interest in the practicability of restoration of the lost New Jersey Atlantic white cedar forests let to a study and this excellent report that nicely summarizes the history of the white cedar lumber business in NJ from the 1600s through the 20th century: Atlantic white-cedar Ecology and Best Management Practices Manual By: Kristin A. Mylecraine and George L. Zimmermann Under the editorial guidance of the NJ Atlantic white-cedar Initiative Steering Committee 2000.

The researchers concluded that at the time of European settlement, there may have been as many as 500,000 acres of Atlantic white cedar in NJ.  By 1995 only 115,000 acres were estimated to remain and it is gone from the Meadowlands.  They even mined the logs buried in the swamps.  Heavy cedar cutting also occurred in other regions. In the 19th century, in North Carolina cedar harvesting was expedited by the development of steam-powered trains and dredging equipment, to drain previously inaccessible cedar swamps. Some speculate that 50% of all the existing white-cedar acreage in the state was cut between 1870 and 1890.  The lumbermen not only raped the land but the raped the swamps too!

With the hope of better protecting AWC wetlands, the  NH Heritage Bureau in 1993 commissioned a study that found 20 larger sites remaining in NH, many linked to glacial features like kettle holes and moraine hollows. Changes in water levels from dams to the draining of wetlands has been a factor in loss of AWC forests in NH.  In 1994 – less than 550-600 acres Atlantic white cedar remained, many of the locations are along the coast.

Another public one is the Cooper Cedar Woods in New Durham owned by the Forest Society

 “A short trail skirts the edge of an Atlantic White Cedar Basin Swamp, which is a rare natural community. This community features very slow-growing cedar trees adapted to wet conditions and an assemblage of uncommon plants that depend on just this particular habitat to survive.”

Conveniently, Kevin Martin a member of our NH big Tree Committee has just published a hiking guide book, Big Trees of New Hampshire that describes  28 short hikes to find 85 of the largest trees in NH; Maps, Trails, & GPS.   Included is another Forest Society Atlantic white cedar location in Kingston at the Webster Wildlife and Natural Area. 

To order the book that provides wonderful photos, maps and directions go to Enfield Publishing  or email

To see the NH Big Tree list of Champion trees including a few Atlantic white cedars and instructions for submitting a nominations go to NH Big Tree Program



             UNH Cooperative Extension and the NH Division of Forests and Lands sponsor the NH Big Tree program in cooperation with the National Register of Big Trees through American Forests.