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I'm not sure of the tree type but I have 4 and 3 are healthy and 1 not.
First photo shows the good tree and the other photos show the diseased tree.
I have sprayed with EcoPestOil, but no improvement.
What can you please advise?
Hello @PAF
Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your plant.
Based on the photos you provided and your description, your plant appears to be a type of Lilly Pilly, likely Syzygium australe or Syzygium smithii, which are commonly used in gardens as screening or hedge plants. These trees are generally hardy but can suffer from certain pests and diseases, especially when stressed. The unhealthy tree shows signs such as yellowing leaves with black and brown spotting, leaf curling and distortion, dieback of new growth, and an overall thinner canopy compared to the healthy trees.
These symptoms suggest a combination of pest damage and fungal infection. It’s possible that the tree was affected by psyllids or scale insects, common sap-sucking pests of Lilly Pilly and although you treated it with Eco PestOil, the damage may have already invited secondary issues such as sooty mould or even fungal diseases like myrtle rust.
The blackened areas on the leaves may be sooty mould, which is a fungus that grows on the sugary residue (honeydew) left behind by pests. While the mould itself doesn't directly infect the plant, it can block sunlight and reduce the plant's ability to photosynthesise. The yellowing and browning of the leaves, especially at the tips, also suggest root stress or nutrient deficiency, possibly linked to waterlogging or poor soil drainage.
To help the tree recover, begin by pruning off the most affected leaves and stems to reduce the fungal load and improve airflow. Follow up with a fungicide either a potassium bicarbonate-based option like Eco-fungicide or a copper-based spray which can help control fungal growth. Apply the spray thoroughly and reapply every 7 to 10 days as needed. Although Eco PestOil is a useful treatment for sap-sucking insects, it won’t fix sooty mould if the pests are already gone. It should only be reapplied under the right conditions: in the cool of morning or late afternoon, and never on a hot or stressed plant.
Additionally, apply a slow-release, low-phosphorus fertiliser suited to native plants to improve the tree’s health. Follow that with a seaweed-based tonic like Seasol to support root growth and immunity. Check that the soil around the tree drains properly Lilly Pillies can suffer if left in soggy ground. Since your other trees are healthy, the issue may be isolated to this one location, possibly due to different soil conditions or past root damage. Keep an eye on the surrounding plants for any signs of spread. With proper trimming, treatment, and support, your plant has a good chance of recovering.
Please remember to wear personal protection such as gloves, goggles and a mask when spraying your plants.
If you need further assistance, please let us know.
Eric
