Ulmus 'Morton Plainsman' Explained

Ulmus 'Morton Plainsman'
Hybrid:	U. pumila × U. davidiana var. japonica
Genus:	Ulmus
Cultivar:	'Morton Plainsman' =
Origin:	US

Ulmus 'Morton Plainsman' (selling name) is a hybrid cultivar raised by the Morton Arboretum from a crossing of Siberian Elm (female parent) and a Japanese Elm grown from openly pollinated seed donated by the Agriculture Canada Research Station at Morden, Manitoba. Tested in the US National Elm Trial coordinated by Colorado State University, https://web.archive.org/web/20080226012323/http://treehealth.agsci.colostate.edu/research/nationalelmtrial/NET_Cultivars.htm averaged a survival rate of 78% after 10 years.^[1]

Description

has modest upright growth, increasing in height by an average of 0.8 m in an assessment at U C Davis,^[2] with leaves much the same size and colour of the American Elm. http://www.ca.uky.edu/agcollege/plantpathology/vaillanc/for410/Dutch%20Elm%20Disease/BASIC/DED/CORE/00/00/F1C.HTML#_Vanguard However, its performance in the southern United States has not impressed, and it was dismissed, along with its Morton stablemates and, as "ugly" by Michael Dirr, Professor of Horticulture at the University of Georgia http://www.greenbeam.com/rs/nm_pdfs/16338_013.pdf, on account of its "wild" growth and splaying branches.

Pests and diseases

Although resistant to Dutch elm disease in the US, remains very susceptible to pests such as the elm-leaf beetle Xanthogaleruca luteola^[2],^[3] Japanese beetle,^[4] and cankerworms.

Cultivation

In trials at the University of Minnesota, was found to have the second highest (after ) incidence of branch breakage occasioned by bark inclusions.^[5] However, the tree has a high degree of drought and cold tolerance making it particularly suitable for afforestation in the Great Plains.^{[6] [7]} In artificial freezing tests at the Morton Arboretum^[8] the LT50 (temp. at which 50% of tissues die) was found to be −40°C.

The tree is currently being evaluated in the National Elm Trial https://web.archive.org/web/20080226012323/http://treehealth.agsci.colostate.edu/research/nationalelmtrial/NET_Cultivars.htm coordinated by Colorado State University. It is not known to have been introduced to Australasia.

Hybrid cultivars

was crossed with the hybrid cultivar ; a selection from the resultant seedlings was marketed under the name 'Charisma', later changed to 'Morton Glossy' = .

Accessions

North America

• Bartlett Tree Experts, US. Acc. nos. 2001–106, 2001-108
• Brenton Arboretum, US. 5 trees, acquired 2009. Acc. no. not known.
• Chicago Botanic Garden, US. 2 trees, no other details available.
• Dawes Arboretum https://web.archive.org/web/20071025005915/http://www.dawesarb.org/collectionsgardens/plant-search.asp, US. 3 trees, no acc. details available.
• Holden Arboretum, US. Acc. no. 00 - 127
• Morton Arboretum, US. Acc. nos. 273 - 97, 4 - 2004, 156 - 2005.^[9]
• Smith College, US. Acc. no. 36505
• University of Idaho Arboretum, US. Two trees. Acc. no. 2000093

Europe

• Grange Farm Arboretum, Lincolnshire, UK. Acc. no. 1139.

Nurseries

North America

• Acorn Farms http://www.acornfarms.com/acornfarmscontactus.htm, Galena, Ohio, US.
• Bailey Nurseries http://www.baileynurseries.com/, St. Paul, Minnesota, US.
• J. Frank Schmidt & Son https://www.google.com/search?hl=en&q=J.+Frank+Schmidt+&btnG=Google+Search&meta=, Boring, Oregon, US.
• Johnson's Nursery http://www.johnsonsnursery.com/, Menomonee Falls, Wisconsin, US.
• Sun Valley Garden Centre http://www.qscaping.com/NetPS-Engine.asp?CCID=20000011&page=results&Keyword=ulmus&Category=&Type=&Spread=Any&SpreadDim=feet&Growth=&Hardiness=7&Height=Any&HeightDim=feet&Canopy=&Application=&Texture=&Wildlife=&Form=&Density=&FlowerColor=&FlowerColorJS=&FoliageColor=&FoliageColorJS=&FallColor=&FallColorJS=&FruitPeriod=&BarkColor=&BarkColorJS=&FlowerPeriod=&Variegation=&VariegationJS=&FruitColor=&FruitColorJS=&Edible=&BarkTexture=&SunShade=&Moisture=&Pollution=&SoilType=&pH=&Submit=Search, Eden Prairie, Minnesota, US.

External links

• 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.
• http://www.mortonarb.org/plantinfo/plantclinic/phc/New-Elms-For-The-Landscape.pdf. Miller, F. (2002). New elms for the landscape and urban forest.

Notes and References

1. Griffin, J.. et al.. 2017. Ten-Year Performance of the United States National Elm Trial. Arboriculture & Urban Forestry. 43(3):107 - 120. International Society of Arboriculture, Atlanta, US.
2. McPherson, G. et al. (2008). National elm trial: Initial report from Northern California. Western Arborist, Fall 2009, 32 - 36.
3. Web site: Elm Leaf Beetle Survey. 17 July 2017. https://web.archive.org/web/20110719132152/http://www.sunshinenursery.com/survey.htm. 2011-07-19.
4. 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.
5. Giblin, C. P. & Gillman, J. H. (2006). Elms for the Twin Cities: A Guide for Selection and Maintenance. University of Minnesota.
6. Santamour . Frank S. . Bentz . Susan E. . May 1995 . Updated Checklist of Elm (Ulmus) Cultivars for use in North America. Journal of Arboriculture . 21 . 3. 122–131 . 20 June 2016.
7. Ware, G. (1992). Morton. Arb. Quarterly 28(1): 1 - 5, 1992.
8. 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, Japan.
9. https://www.cirrusimage.com/tree_vanguard_elm/ Photographs of Morton Arboretum elm, Acc. no. 273-97; cirrusimage.com