The 'dwarf' elmcultivarUlmus 'Jacqueline Hillier' ('JH') is an elm of uncertain origin. It was cloned from a specimen found in a private garden in Selly Park, Birmingham, England, in 1966.[1][2][3] The garden's owner told Hillier that it might have been introduced from outside the country by a relative.[4] Hillier at first conjectured U. minor, as did Heybroek (2009).[5][6] Identical-looking elm cultivars in Russia (if they are not imported 'JH') are labelled forms of Siberian Elm, Ulmus pumila,[7][8] which is known to produce 'JH'-type long shoots. Melville considered 'JH' a hybridcultivar from the 'Elegantissima' group of Ulmus × hollandica. Uncertainty about its parentage has led most nurserymen to list the tree simply as Ulmus 'Jacqueline Hillier'. 'JH' is not known to produce flowers and samarae, or (when grown from cuttings) root suckers.
With time 'JH' makes a large shrub, then a small tree, initially of dense habit, but spreading with age if left unpruned. It bears small, double-toothed scabrid leaves 2.5 cm to 3.5 cm long on densely hairy twigs. In winter its tidy 'herringbone' branches and branchlets proclaim it an elm, despite its shrublike size.
Foliage of 'JH'
Bark of 'JH'
Same
Pests and diseases
Resistance to Dutch elm disease is not known, but is probably academic as the tree is unlikely to attain the height at which it would attract the attention of the bark beetles that act as vectors of the disease. In trials in the United States, 'JH' was found to be virtually unaffected by the Elm Leaf Beetle Xanthogaleruca luteola[1].
Cultivation
'JH' is commonly found in cultivation in Europe and the United States,[9] where it is considered particularly suitable for small gardens, rockeries, low hedges, and bonsai. It is said that a hardy tree can survive temperatures as low as −25 °F (−32 °C) in North America.[10] Despite its dwarf nature and its reputation as a slow-grower, 'JH' is said to grow 6 ft (1.8 m) by 6 ft (1.8 m) in ten years,[10] faster than the dwarf wych elm 'Nana'.
The UK TROBI Champion grows at Talbot Manor in Norfolk, measuring 8 m high by 28 cm d.b.h. in 2008. Another at Exbury Gardens in Hampshire measured 6 m high by 35 cm d.b.h. in 2006 [11]
In keeping with the ancient tradition of planting funerary elms to commemorate the dead, specimens of 'Jacqueline Hillier' were planted on either side of the memorial to the dead in the Quintinshill rail disaster, Britain's worst rail disaster, in Rosebank Cemetery, Edinburgh.
'JH' beside the Quintinshill Rail Disaster Memorial, Rosebank Cemetery, Edinburgh.
Accessions
North America
Chicago Botanic Garden, Illinois, US. 1 tree in Educational Center Gardens, listed as U. × hollandica 'Jacqueline Hillier'.