Ulmus 'Frontier'
From Wikipedia, the free encyclopedia
| Ulmus hybrid |
|---|
| Hybrid parentage |
| U. minor subsp. minor × U. parvifolia |
| Cultivar |
| 'Frontier' |
| Origin |
| USA |
The American hybrid cultivar 'Frontier' [2] is a U. S. National Arboretum introduction derived from a crossing of the European Smooth-leaved Elm Ulmus minor subsp. minor with the Chinese Elm Ulmus parvifolia in 1971, a unique example of the hybridization of spring-flowering and autumn-flowering elms. Released in 1990, 'Frontier' develops a vase or pyramidal shape, and glossy green foliage turning to burgundy in autumn. The ultimate height of the tree has yet to be determined, but should be in excess of 15 m. The tree rarely flowers, and has not produced seed [1] [2].
Reputed to have a high resistance to Dutch elm disease and elm yellows (phloem necrosis), it is only moderately resistant to elm leaf beetles. In trials in eastern Arizona [3], 'Frontier' and another American hybrid, 'Regal', were found to have the highest tolerance of the hot and arid climate, notably exhibiting minimal leaf scorch. However, 'Frontier' is known to have sustained winter damage where planted in the Great Plains [4]. This failing was repeated in the elm trials conducted by the University of Minnesota, although the tree often recovered the following year. It was also criticized for its form and integrity, considered "unsuitable" for urban forestry [3].
'Frontier' fared better in 10-year trials at Atherton, California, to evaluate replacements for Californian elms lost to disease: "Strong structure, rapid growth rate, attractive leaf color in spring and fall, and relatively low pruning requirement suggest that Frontier has promise..." [4], although the tree again proved only moderately tolerant of elm leaf beetles. The tree is currently being evaluated in the National Elm Trial [5] coordinated by Colorado State University.
'Frontier' has had a limited introduction to Europe [5], where it is largely restricted to arboreta and elm collections; it also featured in trials in New Zealand during the 1990s at the Hortresearch station, Palmerston North.
Contents |
[edit] Arboreta etc. accessions
- North America
- Bartlett Tree Experts acc. nos. 2001-097/8/9
- Brooklyn Botanic Garden [6], New York, acc. no. 20040606.
- Chicago Botanic Garden, Glencoe, Illinois. No details available.
- Dawes Arboretum [7], Newark, Ohio. 3 trees, no acc. details available.
- Holden Arboretum acc. no. 95-140
- Morton Arboretum acc. nos. 1284-2004, 433-2005
- Scott Arboretum acc. no. 91-242
- Smith College acc. no. 19804, 36005
- Europe
- Brighton & Hove City Council, UK, NCCPG Elm Collection [8].
- Grange Farm, Sutton St. James, Spalding, Lincolnshire, UK. Acc. No. 504
[edit] Nurseries
- North America
- Backyard Trees, Park Hill, Oklahoma.
- Charles J. Fiore [9], Prairie View, Illinois
- ForestFarm [10], Williams, Oregon
- Herd Farm Nursery, Belvedere, Tennessee
- J. Frank Schmidt & Son Co. [11], Boring, Oregon
- Johnson's Nursery [12], Menomonee Falls, Wisconsin
- Jost Greenhouses, Missouri
- North American Plants [13], Lafayette, Oregon, Oregon
- Pea Ridge Forest [14], Hermann, Missouri
- Sunshine Nursery [15], Clinton, Oklahoma
- Europe
[edit] References
- ^ 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, USA.
- ^ Townsend, A. M., Schreiber, L. R., Masters, W. O. and Bentz, S. E. HortScience, 26: 80-81, 1991.
- ^ Giblin, C. P. & Gillman, J. H. (2006). Elms for the Twin Cities: A Guide for Selection and Maintenance. University of Minnesota.
- ^ Costello, L. R. (2004). A 10 -year evaluation of the performance of four elm cultivars in California, U. S. Journal of Arboriculture, March 2004. [1]
- ^ Burdekin, D. A. & Rushforth, K. D. (Revised by Webber J. F. 1996). Elms resistant to Dutch elm disease. Arboricultural Research Note 2/96. Arboricultural Advisory and Information Service, Alice Holt, Farnham, UK.
[edit] External links
- http://www.extension.iastate.edu/Publications/SUL4.pdf Summary, inc. photographs, of elm cultivars resistant to Dutch elm disease available in the USA.
- 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.
