Now deceased, this tree had the per- fect vase-shape of American Elms. Its trunk circumference (CBH) was ap- proximately 13’ 6”. Most leaves were dead by July 2018 and the tree had succumbed to Elm Yellows Disease by early 2019.
Elm Yellows is spread by leafhoppers (3rd photo) and is very aggressive with no known cure. Infection and death of the tree’s phloem girdles the tree and stops the flow of water and nutrients. Even collections of elms that had been carefully managed against Dutch Elm Disease (e.g., at Cornell and Penn State) have been destroyed by Elm Yellows.
The death of this stately tree, promi- nently situated at the home of Presi- dent James Buchanan, was a real loss. But plans are for its wood to be repur- posed by Fritz Schroeder and Martin Stolpe for garden benches, bowls, and other woodcraft.
With a trunk diameter of 5 feet 9 inches, a height of 111 feet, and a branch spread of 83.5 feet (as mea- sured in 2018), this is the second larg- est elm on record in Pennsylvania.
As noted by arboriculturist John Ro- senfeld, this elm could be old enough that the Continental Congress passed beneath its boughs enroute from Lan- caster to York in 1777. To have survived so long, the tree may be among the 1 in 100,000 American Elms that are tolerant of Dutch Elm Disease.
This amazing species is insensitive to length of daylight (i.e., photoperiod) and continues to grow well into au- tumn until injured by frost.