Posted by ILPARW
(southeast Pennsylvania - Zone 6b) on Dec 4, 2017 7:17 PM concerning plant:
Of course the American or White Elm was devastated by the Dutch Elm Disease, even with some Elm Phloem Necrosis, both diseases from east Asia. However, I have seen a number of lone American Elm trees still surviving from the Chicago area to the Philadelphia area, including Delaware. Some of these trees might have survived by isolation, but I think most are the very few that had resistance to DED. Some towns in the west suburbs of Chicago as Hinsdale, Elmhurst, and Des Plaines have really been on the ball by immediately removing any diseased trees and by pruning out infected parts before DED gets to killing trees off, so that, there still are a number of trees alive now in 2021 about 100 years after most were planted. Because this species has 2x as many chromosomes as other elms, it can't be hybridized, so some organizations have brought forth cultivars from resistant trees. The 'Princeton' Elm was already around in New Jersey as a cultivar that happened to be resistant already. A good number of larger, diverse nurseries are offering some American Elms as cultivars with 'Jefferson, New Harmony, Princeton, and Valley Forge' being the most commonly offered. I've seen a few spots in the borough in which I am dwelling in southeast Pennsylvania where some younger trees have been planted by landscape architects in parkways and some public spaces. I believe the Nature Conservancy is working on having resistant elms that are not cultivars, but seed grown.
The native range of the American Elm is large from Nova Scotia out to Alberta, down to east Texas to most of Florida and back up north. It grows fast of about 2 feet/year and lives 175 to 200 years or a little more. It usually gets good golden fall color, but some don't. It develops that wonderful vase shape. The leaves are 4 to 6 inches x 1 to 3 inches and are not really rough to the touch. It releases its many wafer-like samaras in spring, usually May. It is easy to transplant in spring or fall as a young tree, and it has shallow to deep lateral roots. I consider it as the best elm species in the world. It is making a comeback, but should not be planted in such huge numbers as it used to be all along streets or in yards.