Eucalyptus Johnstonii

Stock status (May 2024)

General characteristics:

Hardy:Hardy from -8°C to -20℃ depending on which report you believe. PFAPCertainly as per the photo below from Wicklow, they survived the severe frosts of 2010 here in Ireland.
Soil:Dislikes clay and chalk, though will grow in most others including those low in mineral content. Tolerates drought once established.
Growth:Fast, up to 1.5m per year
Height:45m plus
Biomass:Good firewood, can be coppiced, polarded or logged

Common names

Also known as; Tasmanian Yellow Gum

Can’t say Eucalyptus Johnstonii has been a success for me here at Clounsnaghta, West Clare Ireland, though perhaps it is the soil conditions or my North facing slope. Perhaps the provenance of the seed.

Anyway as you can see from the photo below, those in Wicklow are growing well. Eucalyptus Johnstonii are mentioned in most of the early trials of Eucalyptus in Ireland with good results. There are some interesting specimens dotted around Mount Usher where a few have grown to over 35m. One in the Scottish highlands reaches almost 40m.

Those in the photo below are in Wicklow Ireland

Eucalyptus Johnstonii Wicklow

In the Avondale Forest Park, one Eucalyptus Johnstonii was accurately measured at just over 45m in 2014, source Monumental Trees.

The striking colour of the bark gives them their common name ‘Tasmanian Yellow Gum’, though I would add the one in the photo below looks as though there has been a shower of rain and the colours are probably a bit more vivid than in reality.

Eucalyptus Johnstonii specimen bark

Eucalyptus Johnstonii is generally a stately straight tree with dark brown bark and green foliage. The spread of the crown is limited in comparison to the height of the tree, perhaps making it a good choice for agroforestry 🤔 i.e. you could cultivate grass for grazing beneath it as sunlight will reach down. Assuming they are planted sufficiently far apart.

Eucalyptus Johnstonii specimen

Johnstonii sits well in the traditional Irish landscape and is sometimes used to create screening and hedging.

Johnstonii is also considered to be wind tolerant.

Some reports also suggest that this large Eucalyptus can tolerate coastal exposure, so would be a suitable trial variety for large parts of Ireland.