How to save Brisbane Ryegrass and Kikuyu lawn?

[RomainQ]

Hello everyone, I have this ryegrass/Kikuyu lawn that I seeded mid March (month and a half ago). It went all nice and green with the Rye establishing, but in the last few weeks we're noticing patches of dead looking grass (going orange/yellow) which seem to be spreading. I mowed the lawn for the first time 2 weeks ago, but I saw this issue prior to it (just not as bad). I still water it once a day in the morning. I'm not sure what I'm doing wrong. Is the soil potentially too sandy? Does it need some fertilizer/nutrients to get back up? When trying to pluck the 'dead' grass out, it's still holding, so I want to believe it's not fully dead yet. In some spots, it looks like the weeds are taking over as well. (The dark spots in the second pic is some top soil that I added 2 weeks ago while doing some light reseeding)

Any ideas? Thank you so much.

[EricL]

Hello @RomainQ 

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

It sounds like your lawn is going through a normal seasonal transition, especially since it’s a mix of ryegrass and Kikuyu. The yellowing or orange patches are likely caused by a combination of factors. Ryegrass thrives in cooler weather but can begin to fade or go dormant in late autumn. At the same time, Kikuyu, being a warm-season grass, also slows its growth and can look patchy or pale as the temperature drops. These seasonal changes often make lawns appear unhealthy even when the roots are fine.

A common cause of yellowing is nitrogen deficiency. Your lawn has been growing for over a month and may have used up the nutrients in the soil, especially with regular watering. Feeding it now with a slow-release lawn fertiliser—such as Scotts Lawn Builder All Purpose or Yates Dynamic Lifter Organic Lawn Food from Bunnings—can help restore colour and strength. At this stage, daily watering may be too much. In cooler weather, excessive moisture can lead to root stress or fungal problems, especially in sandy soil. It's best to reduce watering to every two or three days unless conditions are hot and dry.

Mowing may have added stress if it was done too short. Keep your mower set higher, around 40mm, to protect the grass as it matures. The weeds you’re seeing are also common in new lawns where grass coverage is still thin. Avoid full-lawn treatments while your turf is under stress.

The good news is that if the grass still holds when tugged, it’s likely not dead. With proper feeding, less frequent watering, and light weed management, it should bounce back. If you want to maintain green coverage through winter, overseeding with ryegrass again may help, while the Kikuyu will return strongly in spring. 

If you need further assistance, please let us know.

Eric

[RomainQ]

Hello Eric, 

Thanks for your quick reply. I followed your advice and fertilised the lawn and gave it some powerfood. That was a couple of days ago. Since, it looks like it's still dying.. I think some grass is coming off really easily now, and my front lawn is starting to do the same. The only green left is the weeds... I'm wondering what I did wrong?

[MitchellMc]

Hi @RomainQ,

Thanks for the update, and I’m sorry to hear the lawn still isn’t bouncing back. Given what you’ve described—particularly that the grass is now coming away easily and the issue is spreading to the front lawn—it’s likely the problem stems from the way the soil was prepared before seeding.

If the existing soil was too sandy, compacted, low in nutrients, or didn’t have good organic content mixed through, the grass roots may not have established properly. In new lawns, healthy root development is everything—especially with Kikuyu, which needs time to get a deep, strong root system in place to thrive through seasonal changes and compete with weeds.

Even with watering and fertiliser now, if the roots didn’t take hold well in the first place, the grass can easily fail once conditions change or nutrients run low. Poor drainage or waterlogging in sandy or poorly structured soil can also lead to rot and dieback. If the weeds are thriving while the grass is failing, that’s another sign that the conditions aren’t favourable for the turf.

If you can, try digging into a few problem spots to check how well the roots have grown and what the soil feels like beneath the surface. If it’s dry and powdery, overly wet, or thin and lifeless, you might need to consider topdressing or amending the soil to improve structure and nutrition before reseeding again.

Please let me know if you have any questions.

Mitchell