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Hi there, a novice gardener here. I have a growing sweet viburnum hedge in my garden. I'm noticing that some leaves are yellowing and has black dots all over it (please see images). What is happening here? how can I mitigate it?
The hedge IS sprouting new growth, which makes me relieved but still i feel like the plant is not as well as it could be. Even with the new growth, I noticed that there is fuzzy orange and black dots all over them (picture included). Is this normal or is this infestation?
Thank you very much. Your help would be amazing.
Hello @sunnyg
Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your Sweet Viburnum.
You’ve done a great job noticing these early signs, as it really helps to keep your hedge healthy. Based on your photos, your sweet viburnum is showing two distinct but related issues: one fungal and one likely pest-related.
The yellowing leaves with black speckles are showing classic signs of fungal leaf spot. These fungi thrive in warm, humid conditions and spread through water splash, so they’re common on viburnums, especially in spring and early summer. Infected leaves gradually yellow and fall off, reducing the plant’s vigor if untreated. To manage this, remove and dispose of all infected leaves immediately and avoid composting them.
Improve air circulation by light pruning to allow sunlight and airflow through the hedge. Water at the base of the plant rather than overhead, and try to do it in the morning so foliage can dry during the day. Apply a fungicide such as Yates 200ml Liquid Copper Fungicide or Yates 150g Mancozeb Plus Garden Fungicide And Miticide, both of which are available at the store and are safe for ornamental shrubs. Repeat every ten to fourteen days for a few weeks or as recommended on the packet if the problem persists.
The fuzzy orange and black spots you’re seeing on new growth are not normal. They appear to be rust fungus, a separate but common issue in viburnums. Rust spores are orange, rust-coloured, and sometimes hairy or powdery. It can occur concurrently with leaf spot infections because both thrive under similar conditions. Prune away any affected new shoots and destroy them. After pruning, spray the plant with a systemic fungicide that targets rust, such as products containing myclobutanil or triforine such as Yates 750ml Fungus Gun Systemic Disease Spray. Continue regular monitoring because rust can recur quickly if humidity remains high.
It’s encouraging that your plant is putting out new shoots, as that means it’s still strong. After treating the fungal issues, give the hedge a light feed to help it recover. Use a slow-release balanced fertiliser like a “Complete Gardenia, Camellia & Azalea” mix or a general shrub fertiliser high in nitrogen and trace elements. Make sure the soil drains well, because viburnums dislike sitting in waterlogged ground.
Keep mulch a few centimetres away from the stems to prevent fungal spores from splashing back onto the leaves. Maintain good spacing between plants and prune lightly once a year after flowering to reduce humidity inside the hedge.
Please remember to wear personal protection such as gloves, goggles and a mask when spraying chemicals.
If you need further assistance, please let us know.
Eric
noted, Jacob. Thank you. I'll try this today and report back in a few weeks. 
