New Horizon (elm hybrid)
Encyclopedia
An American cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

 raised by the Wisconsin Alumni Research Foundation
Wisconsin Alumni Research Foundation
The Wisconsin Alumni Research Foundation is the nonprofit technology transfer office of the University of Wisconsin–Madison. It is a significant source of research support, independent of federal grants...

 (WARF), 'New Horizon' was derived from a crossing of Siberian Elm
Siberian Elm
Ulmus pumila, the Siberian Elm, is native to Central Asia, eastern Siberia, Mongolia, Xizang , northern China, India and Korea . It is also known as the Asiatic Elm, Dwarf Elm and Chinese Elm. Two varieties are recognized: var pumila and var. arborea, the latter known as Turkestan elm...

 Ulmus pumila with Japanese Elm
Japanese Elm
Ulmus davidiana var. japonica, the Japanese Elm, is one of the larger and more graceful Asiatic elms, endemic to much of continental north-east Asia and Japan.-Description:...

 Ulmus davidiana var. japonica and patented in 1994.

Description

Unlike an earlier crossing of the same species 'Sapporo Autumn Gold', the tree has a compact pyramidal form, with comparatively dense foliage comprising glabrous, dark-green, elliptical leaves < 12 cm long by 7 cm broad, occasionally without the asymmetric bases typical of the genus. The perfect, apetalous wind-pollinated flowers appear in March, followed by the seeds in April; flowering usually begins when the tree is aged 8 years.

The tree's growth is unusual; in an assessment at U C Davis as part of the National Elm Trial
National Elm Trial
The National Elm Trial is an American volunteer effort to evaluate a range of newly developed elm cultivars as replacements for elms destroyed by Dutch elm disease...

, its d.b.h. increased faster than any other of the 15 cultivars, but increase in height was one of the slowest, averaging a modest 0.9 m per annum.

In commerce in the USA, the tree is occasionally propagated by grafting onto an Ulmus pumila rootstock, rather than simply rooting cuttings as normally practiced in North America and Europe. More recently in the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

, cuttings have been successfully grafted onto Belgian Elm Ulmus × hollandica 'Belgica' rootstocks in the hope of making the tree more adaptable to heavy, clayey soils.

Pests and diseases

'New Horizon' has a high resistance, rated 5 out of 5 to Dutch elm disease
Dutch elm disease
Dutch elm disease is a disease caused by a member of the sac fungi category, affecting elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native...

, and is also resistant to elm leaf miner, and verticillium
Verticillium
Verticillium is a genus of fungi in the division Ascomycota, and are an anamorphic form of the Plectosphaerellaceae family. The genus used to include diverse groups comprising saprobes and parasites of higher plants, insects, nematodes, mollusc eggs and other fungi thus it can be seen that the...

 wilt . However, it has proven susceptible to attack by elm leaf beetle Xanthogaleruca luteola
Xanthogaleruca luteola
Xanthogaleruca luteola, commonly known as the Elm Leaf Beetle, is a serious pest of the elm. Indigenous to Europe, it was accidentally introduced to North America. Both the imagines and larvae feed on the emergent leaves of the elm...

http://www.fs.fed.us/psw/programs/cufr/products/CUFR_780_Elm_trials_2009.pdf and Japanese Beetle
Japanese beetle
The beetle species Popillia japonica is commonly known as the Japanese beetle. It is about long and wide, with iridescent copper-colored elytra and green thorax and head...

 in the USA .

Cultivation

The tree has not been an unqualified success. In the elm trials conducted by the University of Minnesota
University of Minnesota
The University of Minnesota, Twin Cities is a public research university located in Minneapolis and St. Paul, Minnesota, United States. It is the oldest and largest part of the University of Minnesota system and has the fourth-largest main campus student body in the United States, with 52,557...

, 'New Horizon' was found to need relatively high levels of maintenance, largely owing to its predilection for co-dominant leaders and heavy side branches . In the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

, removal of sideshoots from the lower trunk was found to be necessary twice a year. In trials in eastern Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 http://www.for.nau.edu/cms/content/view/512/706/ it often exhibited > 25 % crown dieback over winter and a very high level of leaf scorch in summer. The tree is currently being evaluated in the National Elm Trial
National Elm Trial
The National Elm Trial is an American volunteer effort to evaluate a range of newly developed elm cultivars as replacements for elms destroyed by Dutch elm disease...

 http://treehealth.agsci.colostate.edu/research/nationalelmtrial/NET_Cultivars.htm coordinated by Colorado State University
Colorado State University
Colorado State University is a public research university located in Fort Collins, Colorado. The university is the state's land grant university, and the flagship university of the Colorado State University System.The enrollment is approximately 29,932 students, including resident and...

.

'New Horizon' was introduced to Europe by the Conrad Appel nursery (ceased trading 2005) in Darmstadt
Darmstadt
Darmstadt is a city in the Bundesland of Hesse in Germany, located in the southern part of the Rhine Main Area.The sandy soils in the Darmstadt area, ill-suited for agriculture in times before industrial fertilisation, prevented any larger settlement from developing, until the city became the seat...

, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, which propagated the tree under licence as one of the hybrid elms offered in the Resista series http://www.resista-ulmen.com/; the tree is currently propagated by Eisele GmbH. Introduced to the UK, 'New Horizon' was named 'Best New Plant Variety' by Horticulture Week
Horticulture Week
Horticulture Week is a British horticultural periodical, covering nursery production, garden retail, landscaping, arboriculture, garden heritage, groundsmanship and amenity horticulture....

 in 2005, however, an assessment by Butterfly Conservation
Butterfly Conservation
Butterfly Conservation is an insect conservation organisation in the United Kingdom. It is one of the largest insect conservation organisations in the world.-History of the Organisation:...

found its growth on heavy, poorly-drained ground negligible. Nevertheless, the tree has tolerated flooding, by both freshwater in England, and seawater along the Baltic
Baltic region
The terms Baltic region, Baltic Rim countries, and Baltic Rim refer to slightly different combinations of countries in the general area surrounding the Baltic Sea.- Etymology :...

 coast in Germany http://translate.google.co.uk/translate?hl=en&sl=de&u=http://www.resista-ulmen.com/static_website/de/de_6.htm&ei=iFhZTJ3zMKK80gTQktHmCA&sa=X&oi=translate&ct=result&resnum=3&ved=0CA8Q7gEwAg&prev=/search%3Fq%3Darshadi%2Bhillier%26hl%3Den%26sa%3DG. Trees at exposed sites in Hampshire
Hampshire
Hampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...

 exhibited much the same degree of dieback experienced in the Arizona trials despite the extreme differences in climate. However no losses have been sustained, and in sheltered conditions on deep loam
Loam
Loam is soil composed of sand, silt, and clay in relatively even concentration . Loam soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils...

 over chalk
Chalk
Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite plates shed from micro-organisms called coccolithophores....

, 'New Horizon' grew healthily if relatively slowly, increasing in height by approximately 50 cm per annum, less than half the speed of the Dutch hybrids such as 'Dodoens'
Ulmus 'Dodoens'
The Dutch hybrid cultivar Ulmus Dodoens was derived from a selfed seedling of a hybrid of the Exeter Elm Ulmus glabra 'Exoniensis', and the Himalayan Elm Ulmus wallichiana...

 planted with it. The trees in the English trials first flowered aged 10 years, in late March .

In 2004, 80 trees were donated to the Greater London Council
Greater London Council
The Greater London Council was the top-tier local government administrative body for Greater London from 1965 to 1986. It replaced the earlier London County Council which had covered a much smaller area...

 as part of the grower's European Elm City promotion; similar gifts were also made to Belfast
Belfast
Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...

, Cardiff
Cardiff
Cardiff is the capital, largest city and most populous county of Wales and the 10th largest city in the United Kingdom. The city is Wales' chief commercial centre, the base for most national cultural and sporting institutions, the Welsh national media, and the seat of the National Assembly for...

 (Pontcanna Park), and Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

 (the central City Park). In 2010, 100 trees were planted in the London borough of Enfield
Municipal Borough of Enfield
Enfield was a local government district in Middlesex, England from 1850 to 1965.The parish of Enfield adopted the Public Health Act 1848 in 1850, and formed a local board of health of 12 members to govern the area. The local board's area was reconstituted by the Local Government Act 1894, and...

 to aid and abet the conservation of the White-letter Hairstreak Satyrium w-album. http://www.thisislondon.co.uk/standard/article-23808776-rare-butterflies-given-a-new-leaf-of-life.do Another hundred have been included in the tree planting at the Olympic Park
Olympic Park, London
The Olympic Park in London is a new sporting complex currently under construction, adjacent to the Stratford City development in Stratford, Bow, Leyton & Homerton in East London for the 2012 Summer Olympics and Paralympics....

. Specimens have also been planted in various parts of Edinburgh
Edinburgh
Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...

, such as Castle Terrace, the Meadows and Inverleith Park.

North America

  • Bickelhaupt Arboretum
    Bickelhaupt Arboretum
    Bickelhaupt Arboretum is a non-profit arboretum located at 340 South 14th Street, Clinton, Iowa. It is open dawn to dusk daily without charge....

    , Clinton
    Clinton, Iowa
    Clinton is a city in and the county seat of Clinton County, Iowa, United States. The population was 26231as of 2010. Clinton, along with DeWitt, Iowa , was named in honor of the seventh governor of New York, DeWitt Clinton. Clinton is the principal city of the Clinton Micropolitan Statistical...

    , Iowa
    Iowa
    Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...

    . Acc. no. 01-008
  • Chicago Botanic Garden
    Chicago Botanic Garden
    Located at 1000 Lake Cook Road, Glencoe, Illinois, USA, the Chicago Botanic Garden is a living plant museum situated on nine islands featuring 24 display gardens and surrounded by four natural habitats: McDonald Woods, Dixon Prairie, Skokie River Corridor, and Lakes and Shores. The Garden is open...

    , Glencoe
    Glencoe, Illinois
    Glencoe is a village in Cook County, Illinois, United States. As of the 2010 census, the village population was 8,723. Glencoe is located on suburban Chicago's North Shore. Glencoe is located within the New Trier High School District. Glencoe is regarded as one of the most affluent suburbs on...

    , Illinois
    Illinois
    Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

    . 3 trees, no other details available.
  • Morton Arboretum
    Morton Arboretum
    The Morton Arboretum, in Lisle, Illinois, covers 1,700 acres and is made up of gardens of various plant types and collections of trees from specific taxonomical and geographical areas. It includes native woodlands and a restored Illinois prairie. The Arboretum has over 4,100 different species of...

    . Acc. no. 271-2008.

Europe

  • Arboretum de la Petite Loiterie
    Arboretum de la Petite Loiterie
    The Arboretum de la Petite Loiterie is a young arboretum located in Le Sentier, Monthodon, Indre-et-Loire, Centre, France. It is open a few days per month; an admission fee is charged....

     http://lapetiteloiterie.free.fr/html/presentation/especes.html, Monthodon
    Monthodon
    Monthodon is a commune in the Indre-et-Loire department in central France....

    , France
    France
    The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

    . No details available.
  • Botanischer Garten Marburg http://web.uni-marburg.de/botgart/, Marburg
    Marburg
    Marburg is a city in the state of Hesse, Germany, on the River Lahn. It is the main town of the Marburg-Biedenkopf district and its population, as of March 2010, was 79,911.- Founding and early history :...

    , Germany
    Germany
    Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

    . No details available.
  • Brighton & Hove
    Brighton & Hove
    Brighton and Hove is a unitary authority area and city on the south coast of England. It is England's most populous seaside resort.In 1997 Brighton and Hove were joined to form the unitary authority of Brighton and Hove, which was granted city status by Queen Elizabeth II as part of the millennium...

     City Council, NCCPG Elm Collection http://www.brighton-hove.gov.uk/index.cfm?request=c1108042, UK.
  • Great Fontley Farm, Fareham
    Fareham
    The market town of Fareham lies in the south east of Hampshire, England, between the cities of Southampton and Portsmouth, roughly in the centre of the South Hampshire conurbation.It gives its name to the borough comprising the town and the surrounding area...

    , UK. Butterfly Conservation
    Butterfly Conservation
    Butterfly Conservation is an insect conservation organisation in the United Kingdom. It is one of the largest insect conservation organisations in the world.-History of the Organisation:...

    elm trials plantation, Home Field K4, planted 2007.
  • Royal Horticultural Society
    Royal Horticultural Society
    The Royal Horticultural Society was founded in 1804 in London, England as the Horticultural Society of London, and gained its present name in a Royal Charter granted in 1861 by Prince Albert...

     Gardens, Wisley
    Wisley
    Wisley is a small village in Surrey, England. It lies between Cobham and Woking. It is the home of the Royal Horticultural Society's Wisley Garden. The River Wey runs through the village....

    , UK. No details available.
  • Sir Harold Hillier Gardens
    Sir Harold Hillier Gardens
    The Sir Harold Hillier Gardens is an arboretum comprising 72 hectares accommodating over 42,000 trees and shrubs in about 12,000 taxa, notably a collection of oaks, camellia, magnolia and rhododendron....

    , UK. Acc. no. 2004.0177

North America

  • Carlton Plants, LLC http://www.carltonplants.com/, Dayton, Oregon
    Dayton, Oregon
    Dayton is a city in Yamhill County, Oregon, United States. The population was 2,119 at the 2000 census. As of July 2007 its estimated population was 2,495.-History:...

    .
  • Charles J. Fiore Nursery http://www.cjfiore.com/index.htm, Prairie View, Illinois
    Illinois
    Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

    .
  • J. Frank Schmidt & Son http://www.google.co.uk/search?hl=en&q=J.+Frank+Schmidt+&btnG=Google+Search&meta=, Boring
    Boring, Oregon
    Boring is an unincorporated community located in Clackamas County, Oregon, United States, on Oregon Route 212. It is approximately eight miles south of Gresham and about the same distance from Clackamas, both suburbs of Portland. The town is roughly twenty-two miles southeast from downtown...

    , Oregon
    Oregon
    Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

    .
  • Johnson's Nursery http://www.johnsonsnursery.com/, Menomonee Falls, Wisconsin
    Wisconsin
    Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...


Europe

  • Bonte Hoek kwekerijen http://www.bontehoek.nl http://bontehoek.nl/catalogus/product_info.php?cPath=32&products_id=184&osCsid=96636c70581f378d125ab3e5035b6215, Glimmen
    Glimmen
    Glimmen is a village that is part of the municipality of Haren, which lies in the province Groningen in the Netherlands. It is 10 kilometres to the city of Groningen and 5 kilometre to Haren. Glimmen has about 1700 inhabitants...

    , Netherlands
    Netherlands
    The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

    .
  • Clasen & Co Baumschulen GmbH, D-Rellingen
    Rellingen
    Rellingen is a municipality in the district of Pinneberg, in Schleswig-Holstein, Germany. It is situated approx. 7 km east of Pinneberg, and 10 km northwest of Hamburg. Population as of 31.12.2007 is 13.746. The total land area are 13,19 km²....

    , Germany
  • Eisele GmbH & Co KG Darmstadt
    Darmstadt
    Darmstadt is a city in the Bundesland of Hesse in Germany, located in the southern part of the Rhine Main Area.The sandy soils in the Darmstadt area, ill-suited for agriculture in times before industrial fertilisation, prevented any larger settlement from developing, until the city became the seat...

    , Germany.
  • Hillier Nurseries http://www.hilliertrees.co.uk/news.php http://www.hilliertrees.co.uk/, UK.
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