How to save dying Sliver Princess eucalyptus tree?

Bluetonge

Dear Ms/Sir,

The Silver Princess (Eucalyptus Caesia) in my garden is mature and has always flowered normally including last year but this spring it has lost most of its leaves, many branches are dead and the bark is curling off the trunk. There is some spotting on the remaining leaves.

There has been no changes to its environmental conditions such as soil, watering etc.

Can you help me?

Thanks and kind regards,

Bluetongue

EricL

Hello @Bluetonge 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your silver princess eucalyptus tree.

It sounds like your Eucalyptus caesia (Silver Princess) is under some stress, which could be due to a few potential factors. The symptoms you're describing—leaf loss, dead branches, curling bark, and spotting on remaining leaves—may indicate a fungal disease or root rot. Although Eucalyptus caesia is typically resilient, it is somewhat vulnerable to pathogens like Phytophthora root rot, which can cause dieback and similar issues. Even though you haven’t changed the watering or soil conditions, fungal diseases can still take hold, especially after unusually wet periods or if soil drainage isn’t optimal.

Environmental factors may also be playing a role. Mature Eucalyptus trees can sometimes react to delayed stress from extreme temperatures, such as a cold snap or sudden heatwave, even if these happened a season or two ago. This delayed response can appear in the form of leaf drop and bark curling. Additionally, pests or diseases may be involved in the spotting on the leaves, as Eucalyptus can sometimes suffer from pests like psyllids or eucalyptus beetles, or from fungal leaf spots caused by pathogens like Pseudocercospora or Alternaria.

To address these issues, consider pruning any dead branches to encourage healthier growth and prevent the spread of disease. A fungicide treatment specific to eucalyptus or trees, in general, could help if fungal disease is indeed the cause. It may also be worth carefully examining part of the root system to check for any signs of rot, such as soft, discolored, or foul-smelling roots. If you suspect root issues, improving soil drainage could help reduce further damage. 

However, looking at the trees current condition, I'm not sure if it can still recover. I also suggest engaging the services of an arborist to give you a more in-depth diagnosis.

Let me call on our experienced members @Noelle and @mich1972 for their recommendations.

If you need further assistance, please let us know.

Eric