Picea glehnii (F. Schmidt) Mast.

Picea glehnii has a relatively narrow distribution in the wild, in the southern half of Sakhalin island off Russia’s Pacific coast, and on Hokkaido and in the mountains of northern Honshu in Japan. It was discovered on Sakhalin in 1861 by Peter von Glehn, a Baltic-German member of the Russian Geographical Society’s expedition to the far east. Glehn’s colleague Schmidt published the discovery in 1868 (as Abies glehnii; Masters made the combination in Picea in 1880 – Plants of the World Online 2024). They found it growing there on plains and in valleys, never attaining great size, being a maximum of about 30 cm dbh (Elwes & Henry 1906–1913). As one tracks south through its range larger examples may be found. Wilson saw trees to 40 m tall around Kitami on Hokkaido (Wilson 1916) and in isolated populations in northwestern Honshu trees over 35 m have been recorded (Elwes & Henry 1906–1913).

The Veitchian collector Charles Maries found this spruce in northern Honshu in 1877, but according to Bean (1976) it was not successfully established in UK cultivation until the late 1890s. Several from an 1897 planting thrive still on the Jubilee Terrace at Murthly Castle, Perthshire; the tallest at 22 m (× 61 cm dbh in 2017) grows very near the champion Picea omorika, while a short distance away is the UK and Ireland champion for girth, at 21 m × 81 cm dbh in 2017. At Eastnor Castle, Herefordshire, an excellent tree, and the joint UK and Ireland champion for height, was 24 m × 63 cm dbh in 2023, having increased modestly since 1984 when it was 21.3 m × 48 cm dbh (Clarke 1988). Others UK trees have achieved 24 m at Crarae, Argyll, and Lael, Wester Ross (Tree Register 2008). The origin of all this material is unknown.

Picea glehnii was in cultivation in Germany before 1891, again from unknown source, while the Danish forester Johannes Rafn sent seedlings to Mustila Arboretum in Finland in 1908; these trees are still extant and have aged better than many other spruces in the arboretum (Arboretum Mustila 2024). The Arnold Arboretum in the US has multiple accessions of Sakhalin Spruce, the oldest dating to 1894; one of the best trees of that vintage has achieved a dbh of 66 cm, while a plant collected by Nicholson and Hay in Hokkaido in 1986 has reached 22 cm dbh (Arnold Arboretum 2024). Clearly this is a species better suited to continental climate regimes, but even in those parts of Europe that can claim such a climate, Sakhalin Spruce has only ever retained a toe hold in cultivation, being of very slow growth, modest stature and limited ornamental value.

Recent investigations into the genetic structure of of Picea glehnii have determined that, whilst there is ‘unambiguous species delimitation’ between it and P. jezoensis, there is also evidence of some introgression, particularly in southern Sakhalin (Aizawa et al. 2015). Purported hybrids are in cultivation, for example at Gothenburg Botanic Garden, Sweden (1997–1068, from a University of Helsinki expedition) but this tree resembles P. jezoensis subsp. jezoensis in its vegetative features (pers. obs. 2019, cones not seen).