It is closely related to Eucalyptus subcrenulata (Alpine yellow gum), which is less vigorous but hardier. The identification of the two species is frequently confused, and plantings of trees identified as E. johnstonii in the UK often prove to be E. subcrenulata. E. johnstonii is a vigorous tree that grows to large dimensions in favourable conditions. It requires a mild wet climate to grow well. In its native habitat in Tasmania it tends to occur on poor soils, but it appears to grow well on well-drained mineral soils. Based on the locations where it grows in the British Isles, it is likely to tolerate temperatures to -12°C, but this has not been critically tested and there is likely to be considerable provenance variation. It deserves to be trialled alongside E.nitens and E.denticulata.
Eucalyptus johnstonii in a former trial planting (probably dating from the 1930s) at Avondale, Co. Wicklow.