How to treat buffalo lawn with spotty white blades?

[Ee11]

I have beautiful buffalo lawn, and in the last few weeks there has been a patch that has blades turning spotty white. Started in a small area but is now increasing in size. I'm not sure what's caused it - the lawn has otherwise been healthy recently, had lots of rain in the last month or two. I used Scotts Lawn Builder Grub and Insect control about 6 weeks ago, and the rest of the lawn is now looking amazing.

I've attached some photos of the general area as well as close up of the blades of grass.

There is a tree next door that is coming in to flower, which could possibly be a Golden Penda (yet to have the yellow flowers come out - picture attached) - does this change in the lawn look like allelopathy? Or is it likely to be a different cause?

And what should I do about it?

[EricL · Accepted solution]

Hello @Ee11 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your buffalo lawn.

Thanks for the detailed description, from what you’ve shared, it sounds like your buffalo lawn is showing early signs of either a fungal issue or environmental stress, rather than something like allelopathy from the neighbouring tree. Golden Penda (Xanthostemon chrysanthus) isn’t known for strong allelopathic effects, so while it’s not impossible, it’s far less likely to be the culprit than moisture-related fungal disease or a chemical reaction.

Buffalo grass is generally hardy, but after extended periods of rain (especially in warm, humid conditions), it can develop fungal problems. The spotty white or bleached patches on the blades, especially if the affected patch is spreading, is consistent with a fungal issue like Grey Leaf Spot or Helminthosporium (Leaf Spot).

Here’s some recommended steps to treat the fungal infection:

1. Apply a lawn fungicide:
   
   Pick up a product like Yates Mancozeb, available at Bunnings. This can treat most fungal problems in lawns. Apply as directed and reapply in 10–14 days if the problem persists. Avoid mowing for a few days after applying.
    
2. Improve airflow and drainage:
   
   If the area stays damp, aerate the soil with a garden fork to help with drainage. Buffalo loves moisture but hates soggy roots, especially during humid periods.
    
3. Avoid overfeeding:
   
   While your use of Scotts Lawn Builder was appropriate, sometimes applying fertiliser when the soil is too moist or when disease is already starting can make things worse. Hold off on more feeding until the patch recovers.
    
4. Mow and disinfect:
   
   Mow the area (not too low) and remove clippings. Wash your mower blades with a weak bleach solution after, to avoid spreading spores.

Please make sure to wear personal protection such as gloves, goggles and a mask when spraying chemicals.

If you need further assistance, please let us know.

Eric