What is wrong with my Silver Princess?
Welcome to the Bunnings Workshop community @roesy. It's wonderful to have you join us and many thanks for your question on Eucalyptus care.
Your Silver Princess (Eucalyptus caesia) is most likely affected by a fungal leaf spot disease, which causes the brown spotting seen on the leaves and is often brought on by moisture sitting on the foliage, poor airflow, or general plant stress. To manage it, start by removing the worst affected leaves and disposing of them rather than composting, as this helps reduce the spread of spores. Make sure the plant is in a well-ventilated spot and avoid watering over the leaves. Water the soil directly and allow it to dry slightly between watering, as this plant prefers drier conditions and good drainage.
If the problem continues or worsens, you can apply a copper-based fungicide like https://www.bunnings.com.au/yates-150g-mancozeb-plus-garden-fungicide-and-miticide_p3010237 every one to two weeks until new growth appears healthy. The damaged leaves won’t recover, but if conditions improve, the new leaves should come through clean.
Here's a helpful guide: How to grow and care for Eucalyptus.
Please let me know if you have any questions.
Mitchell
