Ulmus 'Sapporo Autumn Gold'

Elm cultivar

Ulmus 'Sapporo Autumn Gold'
'Sapporo Autumn Gold' at Antella, Florence, believed to be the largest in Europe.
Genus	Ulmus
Hybrid parentage	U. davidiana var. japonica × U. pumila
Cultivar	'Sapporo Autumn Gold'
Origin	seeds: Sapporo, Japan; cultivated: United States

Ulmus 'Sapporo Autumn Gold' is one of the most commercially successful hybrid elm cultivars ever marketed, widely planted across North America and western Europe, although it has now been largely supplanted by more recent introductions.^[1] Arising from a chance crossing of the Japanese elm (female parent) and Siberian elm, seed was sent in 1958 by Prof. Nobuku Takahashi and his colleagues at the Sapporo Botanical Garden of Hokkaido University, Sapporo,^[2] to Eugene Smalley at the University of Wisconsin–Madison.^[3]^[4] The patent issued in 1975 has expired, and there are now no propagation restrictions. However, the tree has proven weak-wooded on maturity, and its popularity has waned in Europe as a consequence of susceptibility to wind damage. ^[5]

Description

The tree usually forks at 1.5–2 m from the ground to produce a broad, rounded, densely foliated crown, though immature plants produce vigorous side shoots requiring assiduous pruning to maintain shape. The bark is pale grey, and longitudinally fissured to form a random lattice pattern. The leaves are narrowly elliptical, < 9 cm long by < 4.5 cm wide, with 8 mm petioles. As the name implies, the leaves turn pale yellow in autumn.^[6] The perfect, apetalous wind-pollinated flowers appear in early March, followed by the seeds in April; flowering usually begins when the tree is aged six years.

Bark of 30-year-old tree
Foliage
Coastal tree, Mudeford, UK, felled 2017 owing to storm damage
Autumn colour of 'Sapporo AG', Beech Avenue, Bourne, Lincolnshire (November, 2021)

Pests and diseases

'Sapporo Autumn Gold' possesses a very high resistance to Dutch elm disease;^[7]^[8] in trials in Italy, it sustained only 2.8% defoliation and 1.2% dieback when inoculated with unnaturally high concentrations of the fungal pathogen.^[9] The cultivar also has a tolerance of Verticillium wilt.^[10] The tree's foliage was adjudged 'resistant' to black spot by the Plant Diagnostic Clinic of the University of Missouri,^[11] however it can be severely damaged by the elm leaf beetle (Xanthogaleruca luteola) in the United States ^[12] Several mature specimens near the Hampshire coast in England have become (2014) afflicted by Dryad's saddle fungus (Polyporus squamosus).^[13]

Cultivation

In favorable conditions; notably a moist, well-drained soil, the tree can grow at a rate of almost one meter per year. Trials by the Northern Arizona University^[14] found that it is not very tolerant of a hot, arid climate although its leaves sustained comparatively little scorch damage. In trials in southern England conducted by Butterfly Conservation, the tree was found to be intolerant of ponding overwinter.^[13] 'Sapporo Autumn Gold' was first introduced to the UK by technology company Pitney Bowes as part of its 'Elms Across Europe' campaign. The company supplied the cultivar to schools, parks and gardens throughout the UK and Europe.^[15] The tree remains popular in continental Europe but does not assimilate well in the countryside. In trials in France by Cemagref at Nogent-sur-Vernisson, Loiret, it was found to grow too vigorously in hedgerow conditions, eclipsing neighbouring shrubs and consequently creating gaps. In rich soils in the Netherlands the tree grows too fast and has poor wind resistance, whereas in poor, dry conditions growth is slower and more robust.

The hybrid was included in trials^[16] in Canberra, Australia started in 1988, but has not performed well there.

In the UK, 'Sapporo Autumn Gold' has been found to host the endangered white-letter hairstreak butterfly (Satyrium w-album), whose larvae feed exclusively on elm.^[17]

'Sapporo AG': damage sustained during Force 8 gale, Lincolnshire, UK (2020)
Branching of 'Sapporo AG', Bourne, Lincolnshire (2021)
'Sapporo AG', Hamstead Marshall, Berkshire, 2023
Trunk damage caused by major limb loss to storm, Antella, Italy.

Notable trees

The very first tree planted in the UK in 1979 at the Pitney Bowes technology company by Denis Thatcher (where he was a director), survived in perfect health as of 2012;^[18] however Poundland now occupy the site and the land was flattened in 2013/2014. Of five trees planted in 1980 on the green in Clifton, one survives (2016), the others having suffered "catastrophic branch collapse" in storms.^[19] Other notable plantings were as street trees across Bexhill-on-Sea, East Sussex in late 1980s, and as riverside trees along the Ouse in York (from Lendal Bridge to Clifton Ings). The largest specimen in Europe known to Dutch elm expert Hans M. Heybroek grows at the Istituto per la Protezione delle Piante's Monna Giovanella nursery at Antella, near Florence (see Infobox photo), but this too was badly damaged by a storm in 2020.^[13]

Synonymy

Shapiro Autumn Gold: Whitcomb, C. E. Know it and grow it, p. 171, 1976, missprint for 'Sapporo'.

Accessions

North America

Bartlett Tree Experts, US. Acc. nos. 88–1153, 88–1154
Dominion Arboretum, Ottawa, Canada. No acc. details.
Holden Arboretum, US. Acc. no. 91–79

Europe

Arboretum de La Petite Loiterie [5], Monthodon, France. No details available.
Brighton & Hove City Council, UK. NCCPG Elm Collection.^[20] Examples in Blakers Park, Stanmer Park, Preston Park and Woodvale cemetery.
Cambridge Botanic Garden [6], University of Cambridge, UK. No accession details available.
Grange Farm Arboretum, Sutton St James, Spalding, Lincolnshire, UK. Acc. no. not known.
Great Fontley, Fareham, UK, Butterfly Conservation Elm Trials plantation, Home Field.
National Botanic Gardens [7], Glasnevin, Dublin, Ireland. Location: A3 (158).
Royal Botanic Gardens, Wakehurst Place, UK. Acc. no. 1987–4028.
Royal Horticultural Society Gardens Wisley, UK, no details available.
Sir Harold Hillier Gardens, Romsey, UK. Acc. no. 1981.1753.
Thenford House Arboretum, Thenford, UK. No details available.
University Parks, Oxford, UK. Acc. no. 02565, 02566.
Westonbirt Arboretum [8], Tetbury, Glos., UK. Planted 1981, acc. no. 1980/159.
Wijdemeren City Council, Netherlands. Elm collection. Planted at Rading 1, Loosdrecht (2007); Overmeerseweg (2015) and De Vijnen (2017) Nederhorst den Berg.

Australasia

Waite Arboretum [9], University of Adelaide, Australia. Acc. nos. 572, 598

Nurseries

Europe

Ashridge Trees, [10], Castle Cary, Somerset, UK
Coles Nurseries [11], Thurnby, Leicester, UK.
Lorenz von Ehren, Hamburg, Germany. [12]
Van Den Berk (UK) Ltd., [13], London, UK

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, US. [1]
^ Smalley, E. B. and Guries, R. P. Asian Elms: Sources of Disease and Insect Resistance, in Dunn, C P. (ed.). (2000).The Elms - Breeding, Conservation, and Disease Management. Springer Science + Business Media LLC., New York. ISBN 9781461370321
^ Smalley, E. B. & Lester, D. T. (1973). HortScience 8: 514–515, 1973.
^ Smalley, E. B. & Guries, R. P. (1993). Breeding Elms for Resistance to Dutch Elm Disease. Annual Review of Phytopathology Vol. 31 : 325–354. Palo Alto, California.
^ Pinon, J. (2023). Le retour des Ormes dans les villes françaises. Revue forestière française, 74(3), 347–357. https://doi.org/10.20870/revforfr.2023.7686
^ Photograph of autumn colouring of 'Sapporo' elm, [2].
^ Pinon, J., Lohou, C. & Cadic, A. (1998). Hybrid Elms (Ulmus Spp.): Adaptability in Paris and behaviour towards Dutch elm disease (Ophiostoma novo-ulmi). Acta Horticulturae 496, 107–114, 1998.
^ Pinon, J. (July 2007). "Les ormes résistants à la graphiose" [Elms resistant to Dutch Elm Disease] (PDF). Forêt-entreprise (175). Paris, France: IDF: 37–41. ISSN 0752-5974. Retrieved 26 October 2017.
^ "Sapporo Autumn Gold – Resistant Elms". Retrieved 2020-12-28.
^ Burdekin, D.A.; Rushforth, K.D. (November 1996). "Elms resistant to Dutch elm disease" (PDF). Arboriculture Research Note. 2/96. Revised by J.F. Webber. Alice Holt Lodge, Farnham: Arboricultural Advisory & Information Service: 1–9. ISSN 1362-5128. Retrieved 26 October 2017.
^ "Soil and Plant Testing Laboratory - Programs | MU Extension". extension.missouri.edu. Retrieved 2020-12-28.
^ "Elm Leaf Beetle Survey". Archived from the original on 2011-07-19. Retrieved 17 July 2017.
^ ^a ^b ^c Brookes, A. H. (2020). Disease-resistant elm cultivars. Butterfly Conservation, Lulworth, England. [3]
^ "School of Forestry". School of Forestry. Retrieved 2020-12-28.
^ Great British Elm Experiment website, with photograph of one of the original Pitney Bowes' 'Sapporo Autumn Gold' elms: [4]
^ "Broadband, ADSL & ADSL2+ - Netspace". www.netspace.net.au. Retrieved 2020-12-28.
^ Davies, M.(1984). White-letter Hairstreak Project. Newsletter No. 12, Winter 1984/85, West Midlands Branch, Butterfly Conservation.
^ "The Conservation Foundation". www.conservationfoundation.co.uk. Archived from the original on 2011-09-27.
^ Richard Bland, 'The Downs Observer' in The Bristol Six, March 2016, p.14
^ "List of plants in the {elm} collection". Brighton & Hove City Council. Retrieved 23 September 2016.

Elm species, varieties, hybrids, hybrid cultivars and species cultivars

Species, varieties and subspecies

U. alata (Winged elm)
U. americana (American elm)
U. americana var. floridana (Florida elm)
U. bergmanniana (Bergmann's elm)
U. bergmanniana var. bergmanniana
U. bergmanniana var. lasiophylla
U. castaneifolia (Chestnut-leafed or multinerved elm)
U. changii (Hangzhou elm)
U. changii var. changii
U. changii var. kunmingensis (Kunming elm)
U. chenmoui (Chenmou or Langya Mountain elm)
U. chumlia
U. crassifolia (Cedar or Texas cedar elm)
U. davidiana (David or Father David elm)
U. davidiana var. davidiana
U. davidiana var. japonica (Japanese elm)
U. elongata (Long raceme elm)
U. gaussenii (Anhui or hairy elm)
U. glabra (Wych or scots elm)
U. glaucescens (Gansu elm)
U. glaucescens var. glaucescens
U. glaucescens var. lasiocarpa (hairy-fruited glaucescent elm)
U. harbinensis (Harbin elm)
U. ismaelis
U. laciniata (Manchurian cut-leaf or lobed elm)
U. laciniata var. nikkoensis (Nikko elm)
U. laevis (European white elm)
U. laevis var. celtidea
U. laevis var. parvifolia
U. laevis var. simplicidens
U. lamellosa (Hebei elm)
U. lanceifolia (Vietnam elm)
U. macrocarpa (Large-fruited elm)
U. macrocarpa var. glabra
U. macrocarpa var. macrocarpa
U. mexicana (Mexican elm)
U. microcarpa (Tibetan elm)
U. minor (Field elm)
U. minor subsp. minor
U. minor var. italica
U. parvifolia (Chinese or lacebark elm)
U. parvifolia var. coreana (Korean elm)
U. prunifolia (Cherry-leafed elm)
U. pseudopropinqua (Harbin spring elm)
U. pumila (Siberian elm)
U. rubra (Slippery elm)
U. serotina (September elm)
U. szechuanica (Szechuan (Sichuan) or red-fruited elm)
U. thomasii (Rock or cork elm)
U. uyematsui (Alishan elm)
U. villosa (Cherry-bark or marn elm)
U. wallichiana (Himalayan or kashmir elm)
U. wallichiana subsp. wallichiana
U. wallichiana subsp. xanthoderma
U. wallichiana var. tomentosa

Disputed species, varieties and subspecies

U. boissieri
U. minor subsp. canescens (Grey, grey-leafed or hoary elm)
U. elliptica

Hybrids

U. davidiana var. japonica × U. minor
U. × arbuscula
U. × arkansana
U. × brandisiana
U. × diversifolia
U. × hollandica (Dutch elm)
U. × hollandica var. insularum
U. × intermedia
U. × mesocarpa

Species cultivars

American elm	American Liberty Ascendens Augustine Aurea Beaverlodge Beebe's Weeping Brandon Burgoyne JFS Prince II College Columnaris Creole Queen Deadfree Delaware Exhibition Fiorei Flick's Spreader Folia Aurea Variegata Great Plains Hines Incisa Independence Iowa State Jackson Jefferson Kimley Klehmii L'Assomption Lake City Lewis & Clark Littleford Maine Markham Miller Park Minneapolis Park Moline Morden New Harmony Nigricans Patmore Pendula Penn Treaty Princeton Pyramidata Queen City Sheyenne Skinner Upright St. Croix Star Valley Forge Variegata Vase Washington
Cedar elm	Brazos Rim
Chinese elm	A-1 A. Ross Central Park Blizzard BSNUPF Burgundy Burnley Select Catlin Chessins Churchyard Cork Bark D. B. Cole Drake Dynasty Ed Wood Elsmo Emer I Emer II Emerald Prairie Frosty Garden City Clone Geisha Glory Golden Rey Hallelujah Hokkaido Jade Empress King's Choice Littleleaf Lois Hole Matthew Milliken Nire-keyaki Ohio Orange Ribbon Pathfinder Pendens Prairie Shade Prince Richard Red Fall Sabamiki Sagei Seiju Select 380 Sempervirens Small Frye State Fair Stone's Dwarf Taiwan The Thinker Todd True Green UPMTF Ware's Yarralumla Yatsubusa Zettler Ulmus parvifolia f. lanceolata
European white elm	Aureovariegata Colorans Helena Ornata Pendula Punctata Urticifolia
Field elm	Ademuz Albo-Dentata Amplifolia Argenteo-Variegata Atinia Atinia Pyramidalis Atinia Variegata Bea Schwarz Biltii Christine Buisman Concavaefolia Coritana Cretensis Cucullata Cucullata Variegata Dehesa de Amaniel Dehesa de la Villa Dicksonii Dijkwel Erecta Folia Alba-Punctata Glandulosa Goodyeri Hoersholmiensis Holmstruph Hunnybunii Hunnybunii pseudo-Stricta Laciniata Lanuginosa Majadahonda Microphylla Pendula Microphylla Purpurea Microphylla Rubra Monumentalis Pendula Picturata Plotii Propendens Punctata Purpurascens Purpurea Retiro Reverti Rugosa Rueppellii Sarniensis Schuurhoek Silvery Gem Sowerbyi Stricta Suberosa Umbraculifera Gracilis Umbraculifera Viminalis Viminalis Aurea Viminalis Betulaefolia Viminalis Gracilis Viminalis Incisa Viminalis Marginata Viminalis Pendula Viminalis Pulverulenta Viminalis Stricta Virgata Webbiana
Japanese elm	Discovery Freedom Jacan JFS-Bieberich Mitsui Centennial Prospector Reperta Reseda Thomson Validation
Siberian elm	Ansaloni Aurea Aurescens Chinkota Dropmore Dwarf Weeper Green King Hansen Harbin Manchu Mauro Mr. Buzz Park Royal Pendula Pinnato-ramosa Poort Bulten Puszta Pyramidalis Fiorei Zhonghua Jinye
Winged elm	Lace Parasol
Wych elm	Albo-Variegata Australis Camperdownii Cebennensis Concavaefolia Cornuta Corylifolia Purpurea Corylifolia Dovaei Fastigiata Macrophylla Fastigiata Stricta Fastigiata Variegata Firma Flava Gigantea Gittisham Grandidentata Holgeri Horizontalis Insularis Latifolia Latifolia Aurea Latifolia Aureo-Variegata Latifolia Nigricans Luteo Variegata Lutescens Macrophylla Maculata Minor Nana Nigra Nitida Oblongata Pendula Macrophylla Pendula Variegata Pyrenaica Spectabilis Superba Tomentosa

Hybrid cultivars

Androssowii Amsterdam Arno Cathedral Clusius Columella Den Haag Dodoens Escaillard Fiorente Frontier Fuente Umbria Homestead Karagatch Lobel Morfeo Morton Morton Glossy Morton Plainsman Morton Red Tip Morton Stalwart Nanguen New Horizon Patriot Plantyn Plinio Rebella Rebona Recerta Regal Repura Revera San Zanobi Sapporo Autumn Gold Sapporo Gold 2 Stavast Toledo Urban Wanoux Wingham
Dutch elm	Alba Angustifolia Balder Belgica Blandford Canadian Giant Cicestria Cinerea Commelin Dampieri Dauvessei Daveyi Dumont Elegantissima Eleganto-Variegata Etrusca Fastigiata Fjerrestad Folia Rhomboidea Freja Fulva Gaujardii Groeneveld Haarlemensis Klemmer Loke Macrophylla Aurea Major Microphylla Modiolina Muscaviensis Odin Pioneer Pitteurs Serpentina Smithii Superba Tricolor Tyr Vegeta Viminalis Viscosa Wentworthii Pendula Wredei Ypreau
U. × intermedia	Coolshade Fremont Improved Coolshade Lincoln Rosehill Willis