Magnolia dawsoniana Rehd. & Wils.

One of the medium-sized Chinese magnolias with pink flowers on naked twigs, M. dawsoniana is exceptional neither in hardiness, stature or flower size. Nonetheless it has impressive foliage, and a well flowered specimen can be magnificent.

It is most similar to M. sargentiana, especially in flower, but is distinguished by the leaf undersides being more or less glabrous, sometimes rather glaucous, (much hairier in M. sargentiana) and in having on average fewer tepals (9–12 as opposed to 10–14). It is also more inclined than M. sargentiana to make a bushy multistemmed specimen. Rare and declining in the wild, it is apparently a victim of deforestation in Sichuan, one of China’s main timber producing regions. Even in protected areas illegal logging is a threat (IUCN 2021).

It was described by Rehder and Wilson from fruiting specimens collected by Wilson at a single site in Sichuan in 1908 and 1910 (W 1241, W 4116); seed from both was sent to the Arnold Arboretum. The specific epithet commemorates Jackson T. Dawson of the Arnold ‘in appreciation of his consummate skill in propagating the great mass of material that has reached his hands’ (Rehder & Wilson in Sargent 1913). Along with Wilson’s other magnolias, which were proving tender in Massachusetts, the Arnold’s material was sent to French nurseryman Leon Chenault for grafting, distribution in Europe and eventual return to North America (Howard 1980). First flowering in the British Isles was in 1932/3 at Rowallane, N Ireland (Savage 1980). More recent collections include SICH 759 (Gongga Shan, Sichuan, 1991), from which a specimen grows at Howick Hall, Northumberland (Howick Hall Arboretum 2021).

M. dawsoniana makes a large shrub or small-to-medium tree of a broad pyramidal outline, with a ‘twiggy’ network of branches. Growth rates vary, averaging from 30–60 cm per year. The shiny, dark green, leathery leaves are roughly oval in outline, to 15 cm long. The flowers are held horizontally and are very numerous, with white tepals suffused with a rich rosy red, and are faintly fragrant. Opening over quite a long spring season, they are more attractive before they open fully, the tepals hanging limply later. Like most magnolias, it flourishes in a moisture-retentive soil; somewhat acidic soil is ideal but not a requisite. Plenty of space in full sun is also needed for this plant to develop to its potential. Today most plants of M. dawsoniana are either grafted or budded, considerably reducing the time taken for flowering to start, about ten years from propagation being usual.

This species suits milder maritime climates in Western Europe, notably Britain and Ireland and the Low Countries. Examples planted in the early years of its cultivation are relatively few, but include trees at Caerhays Castle, Cornwall, planted 1921 (14 m × 286 cm, 2016); at Trewidden, Cornwall, planted 1946 (17 m × 353 cm, 2014); and at Birr Castle, Co. Offaly, Ireland, again planted 1946 (19 m × 283 cm, 2014 – The Tree Register 2021). In North America it is largely a plant for the Pacific seaboard, especially for wetter parts of the Northwest. A Canadian example in the Greig Garden, Stanley Park has been claimed as the largest magnolia in Vancouver (Cook 1999; 2008), and there are mature specimens in Washington Park, Seattle (Larson 2018). It rarely thrives on the East Coast, although Dirr (2009) mentions a well-budded specimen on Long Island bucking the trend.