The American Elm

American Elm

Ulmus americana, generally known as the American Elm or, less commonly, as the White Elm or Water Elm, is a species native to eastern North America, occurring from Nova Scotia west to Alberta and Montana, and south to Florida and central Texas. The American elm is an extremely hardy tree that can...

 Ulmus americana cultivar 'New Harmony' was raised by the Maryland Agricultural Research Service and released by the United States National Arboretum

United States National Arboretum

The United States National Arboretum is an arboretum in Washington, D.C., operated by the United States Department of Agriculture's Agricultural Research Service as a division of the Henry A. Wallace Beltsville Agricultural Research Center...

 in 1995, along with 'Valley Forge'.

Description

'New Harmony' is considered by some to have a more desirable form than 'Valley Forge' as it grows vertically on its own with a minimum of early training. The original parent tree (located on a roadside in Ohio

Ohio

Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...

) is already over 20 m high, with a slightly greater crown spread. The bole divides into several erect branches about 10 m above the ground terminating in slender, pendulous branchlets .

Growth is rapid, young trees gaining in height by almost 1.7 m per annum in trials at U C Davis, although d.b.h. increase remained a modest 1.8 cm.

Pests and diseases

Although resistant to Dutch elm disease

Dutch elm disease

Dutch elm disease is a disease caused by a member of the sac fungi category, affecting elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native...

 and Elm Leaf Beetle Xanthogaleruca luteola

Xanthogaleruca luteola

Xanthogaleruca luteola, commonly known as the Elm Leaf Beetle, is a serious pest of the elm. Indigenous to Europe, it was accidentally introduced to North America. Both the imagines and larvae feed on the emergent leaves of the elm...

, like most other American Elm cultivars 'New Harmony' is susceptible to Elm Yellows

Elm Yellows

Elm Yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts. Elm Yellows, also known as Elm Phloem Necrosis, is very aggressive, with no known cure. Elm Yellows occurs in the Eastern United States and southern Ontario in Canada. It is caused by phytoplasmas which...

 and Japanese Beetle Popillia japonica . In the trials at U C Davis, the trees remained free of leaf curling aphids (Eriosoma), unlike its U. americana stablemates 'Valley Forge' and 'Princeton'.

Cultivation

'New Harmony' is currently being evaluated in the National Elm Trial

National Elm Trial

The National Elm Trial is an American volunteer effort to evaluate a range of newly developed elm cultivars as replacements for elms destroyed by Dutch elm disease...

 http://treehealth.agsci.colostate.edu/research/nationalelmtrial/NET_Cultivars.htm coordinated by Colorado State University

Colorado State University

Colorado State University is a public research university located in Fort Collins, Colorado. The university is the state's land grant university, and the flagship university of the Colorado State University System.The enrollment is approximately 29,932 students, including resident and...

.
The tree was introduced to the UK in 2010.

Etymology

The tree is named for the Indiana

Indiana

Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...

 town renowned for its social innovations in the 19th century.

Accessions

North America

• Bartlett Tree Experts. Acc. nos. 2001-233, 2001-446.
• Brenton Arboretum
  Brenton Arboretum
  The Brenton Arboretum 121 acres is a new arboretum and botanical garden in early stages of development, located at 2629 Palo Circle, Dallas Center, Iowa, USA. The Arboretum aims to display all Iowa native trees and shrubs suitable to the site, as well as many other tree species which can grow in...
  
  , Dallas Center, Iowa
  Iowa
  Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...
  
  . No details available.
• Longwood Gardens
  Longwood Gardens
  Longwood Gardens consists of over 1,077 acres of gardens, woodlands, and meadows in Kennett Square, Pennsylvania, United States in the Brandywine Creek Valley...
  
  . Acc. nos. 2000-0361, 2002-0412, 2004-0674.
• U S National Arboretum
  United States National Arboretum
  The United States National Arboretum is an arboretum in Washington, D.C., operated by the United States Department of Agriculture's Agricultural Research Service as a division of the Henry A. Wallace Beltsville Agricultural Research Center...
  
   http://www.usna.usda.gov/index.htm, Washington, D.C.
  Washington, D.C.
  Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
  
  , USA. Acc. no. 29003.

Europe

• Grange Farm Arboretum
  Grange Farm Arboretum
  The Grange Farm Arboretum is a small private arboretum comprising 3 hectares accommodating over 800 trees, mostly native and ornamental species or cultivars, notably oaks, ashes, walnuts and elms, growing on a calcareous loam....
  
  , Sutton St. James, Spalding
  Spalding, Lincolnshire
  Spalding is a market town with a population of 30,000 on the River Welland in the South Holland district of Lincolnshire, England. Little London is a hamlet directly south of Spalding on the B1172 road....
  
  , Lincolnshire
  Lincolnshire
  Lincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...
  
  , UK. Whips planted 2011.

External links

• http://www.elmpost.org/2003-08.htm Photograph of New Harmony elms in their original test plot, showing their form of growth.
• http://www.extension.iastate.edu/Publications/SUL4.pdf Summary, including photographs, of elm cultivars resistant to Dutch elm disease available in the USA.
• http://www.sunshinenursery.com/elms.htm Review of current elm selections in the USA.
• http://www.ces.ncsu.edu/fletcher/programs/nursery/metria/metria11/warren/elm.htm Return of the Elm -the status of elms in the nursery industry in 2000. Warren, K., J. Frank Schmidt and Co.