Date: 2011-07-07
Gene Wengert, ewengert@wisc.edu
Beautiful grained hardwood
North American elms are divided into two groups...hard (the subject of this article) and soft (American elm and slippery or red elm). Hard elms include Hard Elms: Rock Elm (Ulmus thomasii), Winged Elm (Ulmus alata), Cedar Elm (Ulmus crassifolia), September Elm (Ulmus serotina).
Hard elms are considerably harder (50 percent or more) than the soft elms; the group name actually makes sense! Unfortunately, all of the hard elms are subject to Dutch elm disease, so supplies of these elms are not as abundant as they once were; these trees are becoming extinct. The good news is that research has found some trees that seem to have a natural resistance. These trees, along with some controlled breeding producing some new varieties including some genetic contributions from Asian elms, seem to offer excellent hopes that the elm tree will be returning to our forests and cities in years to come.
Rock elm (also known as cork elm) is a hardwood tree that is a native to Canada and the northeastern United States. The highest quality lumber is found at mills in north-central Wisconsin, lower Michigan, and southeastern Ontario. Winged and September elms are Southern elm; Cedar elm is most common in Texas; and September elm is found mainly in. However, because the four hard elms are so similar, the lumber from all four is commonly lumped together and sold as rock elm. (In this article, rock elm data is given; the other three are quite similar.)
Many sailing ships, because of elm’s high strength, were made with rock elm timbers. Caskets have been made from elm for many centuries, both in North America and Europe. More recently, rock elm has been used for cheese boxes, vegetable boxes, furniture (especially Danish styles), and upholstery frames, among its many uses. Bending qualities are superb; more severe bending operations should consider using elm, because rejects are few, even though the lumber can be expensive and hard to obtain at times.
Updated: Sep 11, 2011