The

American elm ''Ulmus americana'', generally known as the American elm or, less commonly, as the white elm or water elm, is a species of elm native to eastern North America, naturally occurring from Nova Scotia west to Alberta and Montana, and south to F ...

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...

''Ulmus americana'' 'New Harmony' was raised by the Maryland Agricultural Research Service and released by the United States National Arboretum in 1995, along with 'Valley Forge'. 'New Harmony' proved the most successful ''U. americana'' cultivar in the US National Elm Trial, averaging a survival rate of 85.5% overall.

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 () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

) 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.Townsend, A. M., Bentz, S. E., and Douglass L. W. (2005)
Evaluation of 19 American Elm Clones for Tolerance to Dutch Elm Disease
. ''Journal of Environmental Horticulture'', March 2005, Horticultural Research Institute, Washington, D.C. Growth is rapid, young trees gaining in height by almost 1.7 m per annum in trials at

U C Davis The University of California, Davis (UC Davis, UCD, or Davis) is a public land-grant research university near Davis, California. Named a Public Ivy, it is the northernmost of the ten campuses of the University of California system. The instit ...

, although

d.b.h. Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements. Tree trunks are measured at the height of an adult's breast, ...

increase remained a modest 1.8 cm.McPherson, G. ''et al''. (2008). National elm trial: Initial report from Northern California. ''Western Arborist'', Fall 2009, 32–36.

Pests and diseases

Although resistant to

Dutch elm disease Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America ...

and Elm Leaf Beetle ''

Xanthogaleruca luteola ''Xanthogaleruca luteola'', commonly known as the elm-leaf beetle, is a beetle species in the family Chrysomelidae that is native to Europe but invasive in other parts of the world.http://cisr.ucr.edu/elm_leaf_beetle.html - Center for Invasive Sp ...

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

Elm Yellows Elm yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts."Elm Yellows." Elmcare.Com. 19 Mar. 2008 . Elm yellows, also known as elm phloem necrosis, is very aggressive, with no known cure. Elm yellows occurs in th ...

and Japanese Beetle ''

Popillia japonica The Japanese beetle (''Popillia japonica'') is a species of scarab beetle. The adult measures in length and in width, has iridescent copper-colored elytra and a green thorax and head. It is not very destructive in Japan (where it is control ...

''.Brady, C., Condra, J., & Potter, D. (2008) Resistance of Landscape-suitable Elm (Ulmus spp.) Cultivars to Japanese Beetle, Leaf Miners, and Gall Makers. ''2008 Research Report, Nursery & Landscape Program'', 15–16. University of Kentucky. In the trials at U C Davis, the trees remained free of leaf curling

aphids Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

('' Eriosoma''), unlike its ''U. americana'' stablemates 'Valley Forge' and 'Princeton'.

Cultivation

'New Harmony' is currently being evaluated in the

National Elm Trial The National Elm Trial was an American volunteer effort to evaluate a range of newly developed elm cultivars as replacements for elms destroyed by Dutch elm disease. The Colorado State University College of Agricultural Sciences coordinated the tri ...

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coordinated by Colorado State University. The tree was introduced to the UK in 2010.

Etymology

The tree is named for the

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

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

Accessions

;North America *Bartlett Tree Experts, US. Acc. nos. 2001-233, 2001-446. *

Brenton Arboretum The Brenton Arboretum is a 141-acre arboretum and public garden in Dallas Center, Iowa, United States, established in 1997. The arboretum displays 175 native Iowa trees and shrubs suitable to the site, as well as many other tree species which ca ...

Dallas Center Dallas Center is a city in Dallas County, Iowa, United States. The population was 1,901 during the 2020 census. It is part of the Des Moines–West Des Moines Metropolitan Statistical Area. History Dallas Center got its start in the year 1869, f ...

Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to th ...

, US. No details available. *

Longwood Gardens Longwood Gardens is a botanical garden that consists of over 1,077 acres (436 hectares; 4.36 km2) of gardens, woodlands, and meadows in Kennett Square, Pennsylvania, United States in the Brandywine Creek Valley. It is one of the premier h ...

, US. Acc. nos. 2000-0361, 2002-0412, 2004–0674. *

Morton Arboretum The Morton Arboretum, in Lisle, Illinois, United States, is a public garden, and outdoor museum with a library, herbarium, and program in tree research including the Center for Tree Science. Its grounds, covering 1,700 acres (6.9 square kilometres ...

, Illinois, US. Acc. no. 124-2008. * U S National Arboretumbr>

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

, US. Acc. no. 29003. ;Europe *

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.Ostler, J. (2009) ...

, Sutton St. James, Spalding,

Lincolnshire Lincolnshire (abbreviated Lincs.) is a Counties of England, county in the East Midlands of England, with a long coastline on the North Sea to the east. It borders Norfolk to the south-east, Cambridgeshire to the south, Rutland to the south-we ...

, UK. Whips planted 2011. Acc. no. 1055. *Netherlands Plant Collection, ''Ulmus'': Gemeentehuis, Rading 1, Loosdrecht, gemeente Wijdemeren, planted 2016.Netherlands Plant Collection: Iepen, ''Ulmus''
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References

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 United States. *http://www.sunshinenursery.com/elms.htm Review of current elm selections in the United States. *https://web.archive.org/web/20061205022500/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. {{Elm species, varieties, hybrids, hybrid cultivars and species cultivars , state=collapsed American elm cultivar Ulmus articles missing images Ulmus