Thread: Southern Blue Gum Euc in-ground durability?

Greetings from California, USA, where we have more Blue Gum (Eucalyptus Globulus) than we know what to do with. 10 years ago I removed over 40 trees from my property, the largest of which were 4 feet in diameter at the base.

Fast forward to today - I'm planning a fairly tall retaining wall on my hillside property. The design is steel beam piers with wood lagging, and around here that usually means some kind of fir/pine that has been chemically pressure-treated for ground contact.

However, there is also a local mill that supplies Eucalyptus landscape timbers. I'm attracted by the idea of using "waste" timber as well as not filling my yard with toxic waste (PT lumber). These euc timbers are often used for steps, planter boxes, and low retaining walls but since Eucalyptus is not a widely-used building material here (or anywhere?) there is not a lot of data on the long-term in-ground durability, especially of the heartwood. We have anecdotes, including my own observations of the stumps on my property (sapwood lasts 5 years, oldest in-ground heartwood has no apparent insect or rot damage after 20).

Does anybody in Australia have any documented data or even examples of engineered ground-contact structures using blue gum? Heartwood fence posts? Google is coming up pretty empty. Would be much appreciated.

Thanks!