''Ulmus'' 'Patriot

is a

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two diff ...

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

raised by the

United States National Arboretum The United States National Arboretum is an arboretum in northeast Washington, D.C., operated by the United States Department of Agriculture's Agricultural Research Service. It was established in 1927 by an act of Congress after a campaign by USDA ...

in 1980. Derived from a crossing of the American hybrid 'Urban' (female parent) with the Wilson's Elm (now treated as Japanese Elm ''U. davidiana'' var. ''japonica'') cultivar 'Prospector', 'Patriot' was released to commerce, free of patent restrictions, in 1993.

Tested in the US National Elm Trial coordinated by

Colorado State University Colorado State University (Colorado State or CSU) is a Public university, public Land-grant university, land-grant research university in Fort Collins, Colorado, United States. It is the flagship university of the Colorado State University Syst ...

'Patriot' averaged a survival rate of 85% after 10 years.

Description

The tree develops an upsweeping crown, ultimately adopting a narrow vase-shape. The leaves are slightly leaf shape, obovate, with doubly serrate margins and typically acuminate apices; they are of an average size for the genus, < 10 cm long by 7.5 cm broad, glossy dark green turning yellow in autumn.Santamour, J., Frank, S. & Bentz, S. (1995). Updated checklist of elm (Ulmus) cultivars for use in North America. ''Journal of Arboriculture'', 21:3 (May 1995), 121–131. International Society of Arboriculture, Champaign, Illinois, US

/ref> The perfect flower, perfect,

apetalous Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''coroll ...

wind-pollinated flowers appear in March. Flowering usually begins when the tree is aged six years. Growth is vigorous; specimens in the USDA trials reaching a height of over 13 m (43 ft) and a spread of nearly 8 m (25 ft) after only 13 years. In an assessment at U C Davis as part of 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 ...

, 'Patriot' increased in height by almost 1.5 m and

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, ...

by 2.5 cm per annum.McPherson, G. ''et al''. (2008). National elm trial: Initial report from Northern California. ''Western Arborist'', Fall 2009, pp 32-36.
Image:Ulmus 'Patriot' leaves.jpg, 'Patriot' leaves

Pests and diseases

'Patriot' was found to have a very high resistance to Dutch elm disease (DED) in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, exhibiting 100% survival seven years after inoculation with the causal pathogen. Tolerance of the 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 ...

'' is generally regarded as only moderate, although specimens grown at the aforementioned trials at U C Davis were among those cultivars least affected; resistance to

Japanese Beetle The Japanese beetle (''Popillia japonica'') is a species of Scarabaeidae, scarab beetle. Due to the presence of Predation, natural predators, the Japanese beetle is not considered a pest in its native Japan, but in North America and some region ...

is poor.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. When grown for 11 years among hundreds of infected

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. The trees can live for several hundred years. It is a very hardy species that can ...

s in

Delaware Delaware ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic and South Atlantic states, South Atlantic regions of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey ...

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

, the clone showed no signs of susceptibility to Elm Yellowsbr>
ref name=Townsend>Townsend, A. M. & Douglass, L. W. (2004). Evaluation of elm clones for tolerance of Dutch elm disease. ''Journal of Arboriculture'' 21(3). International Society of Arboriculture, Champaign, IL. however when tested by deliberate infection, tolerance was found to be poor.Sinclair, W. A., Townend, A. M., Griffiths, H. M., & Whitlow, T. H. (2000). Responses of six Eurasian Ulmus cultivars to a North American elm yellows phytoplasma. ''Plant disease'', Vol. 84, No.12, 1266–1270. American Phytopathological Society, St. Paul, MN

Cultivation

The tree performs best in moist but well-drained soils, but will tolerate alkaline ground and salt

In trials by

Northern Arizona University Northern Arizona University (NAU) is a public research university based in Flagstaff, Arizona, United States. Founded in 1899, it was the third and final university established in the Arizona Territory. It is one of the three universities gove ...

in the hot and arid climate of Holbrook, eastern

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

br>
it did not perform as well as Ulmus 'Frontier', 'Frontier' and 'Regal', but not as badly as others such as 'New Horizon' and 'Sapporo Autumn Gold'. In the cooler climes of

Minnesota Minnesota ( ) is a U.S. state, state in the Upper Midwestern region of the United States. It is bordered by the Canadian provinces of Manitoba and Ontario to the north and east and by the U.S. states of Wisconsin to the east, Iowa to the so ...

, it was recommended for every forester's 'Top Ten' list of urban trees.Giblin, C. P. & Gillman, J. H. (2006). ''Elms for the Twin Cities: A Guide for Selection and Maintenance.'' University of Minnesota. 'Patriot' is extremely cold hardy; in artificial freezing tests at the Morton Arboretum Shirazi, A. M. & Ware, G. H. (2004). ''Evaluation of New Elms from China for Cold Hardiness in Northern Latitudes''. International Symposium on Asian Plant Diversity & Systematics 2004,

Sakura The cherry blossom, or sakura, is the flower of trees in ''Prunus'' subgenus '' Cerasus''. ''Sakura'' usually refers to flowers of ornamental cherry trees, such as cultivars of ''Prunus serrulata'', not trees grown for their fruit (although ...

, Japan. the LT50 (temp. at which 50% of tissues die) was found to be - 38 °C. Propagation from softwood cuttings is reputedly easy; taken in mid-May, treated with a 3000 ppm IBA rooting hormone and placed under mist, < 95% should root in less than four weeks. However, commercial propagation is commonly by grafting onto a

Siberian Elm ''Ulmus pumila'', the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes mistakenly called the "Chinese" elm (''Ulmus parvifolia''). ''U. pumila'' has been widely cultivated throughout A ...

Ulmus pumila ''Ulmus pumila'', the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes mistakenly called the "Chinese" elm (''Ulmus parvifolia''). ''U. pumila'' has been widely cultivated throughout A ...

'' rootstock. As height increase can rapidly outstrip stem width, lopping the stem above a leaf node at breast height and vertically training the new leader is recommended to create a more stable structure. The tree is currently being evaluated in the

br>
coordinated by

. 'Patriot' was introduced to the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

and the UK in 2008,Brookes, A. H. (2020). ''Great Fontley Elm Trial, 2020 Report''. Butterfly Conservation, Lulworth, England. and to Italy in 2011 by the

Istituto per la Protezione delle Piante The Istituto per la Protezione delle Piante (IPP), or 'Institute of Plant Protection', is part of the Food Department of the Consiglio Nazionale delle Ricerche (CNR; "Italian National Research Council"), an Italian government organization with the ...

Florence Florence ( ; ) is the capital city of the Italy, Italian region of Tuscany. It is also the most populated city in Tuscany, with 362,353 inhabitants, and 989,460 in Metropolitan City of Florence, its metropolitan province as of 2025. Florence ...

Accessions

North America

Arnold Arboretum The Arnold Arboretum is a botanical research institution and free public park affiliated with Harvard University and located in the Jamaica Plain and Roslindale, Massachusetts, Roslindale neighborhoods of Boston. Established in 1872, it is the ...

, US. Acc. no. 136–98. *Bartlett Tree Experts, US. Acc. nos. 2001–252/3/4, 2001–492/3, 2003–965, 2003–1007/8. *

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 c ...

, US. 5 trees, acquired 2009. Acc. no. not known. *

Chicago Botanic Garden The Chicago Botanic Garden is a botanical garden situated on nine islands in the northern Cook County Forest Preserves. It features 27 display gardens and five natural habitats including Mary Mix McDonald Woods, Barbara Brown Nature Reserve, Di ...

, US. 1 tree, in the Parking Lots. *

Holden Arboretum The Holden Arboretum, in Kirtland, Ohio, is one of the largest arboreta and botanical gardens in the United States, with more than , including devoted to collections and gardens. Diverse natural areas and ecologically sensitive habitats make u ...

, US. Acc. nos. 00–125, 2001–154. *

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 kilometre ...

, US. Acc. no. 122–2001. *North Central Region Plant Introduction Station, ARS,

Ames, Iowa Ames () is a city in Story County, Iowa, United States, located approximately north of Des Moines, Iowa, Des Moines in central Iowa. It is the home of Iowa State University (ISU). According to the 2020 United States census, 2020 census, Ames ha ...

, US. Acc. no. PI566597 * U S National Arboretum,

Washington, D.C. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...

, US. Acc. nos. 72141, 66830. *

University of Idaho The University of Idaho (U of I, or UIdaho) is a public land-grant research university in Moscow, Idaho, United States. Established in 1889 and opened three years later, it was the state's sole university for 71 years, until 1963. The un ...

Arboretum, US. Two trees. Acc. no. 2000090.

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) ...

Lincolnshire Lincolnshire (), abbreviated ''Lincs'', is a Ceremonial counties of England, ceremonial county in the East Midlands and Yorkshire and the Humber regions of England. It is bordered by the East Riding of Yorkshire across the Humber estuary to th ...

, UK. Acc. no. 505. *

, Italy. 2 small (<0.4 m) plants (2011). *

Royal Botanic Garden Edinburgh The Royal Botanic Garden Edinburgh (RBGE) is a scientific centre for the study of plants, their diversity and conservation, as well as a popular tourist attraction. Founded in 1670 as a physic garden to grow medicinal plants, today it occupies ...

, UK. Acc. no. 20110001.

Nurseries

North America

*J. Frank Schmidt & So

Boring, Oregon Boring is an unincorporated community and census-designated place (CDP) in Clackamas County, Oregon, United States. It is located along Oregon Route 212 in the foothills of the Cascade mountain range, approximately southeast of downtown Portl ...

, US. *Johnson's Nurser

Menomonee Falls Menomonee Falls is a village in Waukesha County, Wisconsin, United States. Its population was 38,527 at the 2020 United States census, 2020 census, making it the most-populous village in Wisconsin. It is part of the Milwaukee metropolitan area. ...

Wisconsin Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...

, US. *Pea Ridge Fores

Hermann, Missouri Hermann is a city in and the county seat of Gasconade County, Missouri, Gasconade County, Missouri, United States. It has been the county seat since 1842. It is near the center of the Missouri Rhineland and south of the Missouri River. The popula ...

, US. *Sun Valley Garden Centr

,

Eden Prairie Eden Prairie is a city in Hennepin County, Minnesota, United States. It had a population of 64,198 at the 2020 census, making it the 16th-largest city in Minnesota. The city is adjacent to the north bank of the Minnesota River, upstream from ...

, US.

References

External links

*http://www.extension.iastate.edu/Publications/SUL4.pdf Summary, inc. photographs, of elm cultivars resistant to Dutch elm disease available in the United States. *https://web.archive.org/web/20030413074605/http://fletcher.ces.state.nc.us/programs/nursery/metria/metria11/warren/elm.htm Warren, K., J. Frank Schmidt & Son Co. (2002). ''The Status of Elms in the Nursery Industry in 2000''. {{Elm species, varieties, hybrids, hybrid cultivars and species cultivars , state=collapsed Hybrid elm cultivar Ulmus articles with images Ulmus