Hi
I am looking for advice regarding my lawn. I live in the central west of NSW and have a predominantly Kikuyu grass with a bit of Buffalo and some ryegrass mixed throughout. I have had my lawn thick and lush with regular watering and fertilising as I currently have my house listed for sale but in the last week my lawn has started drying out and and the dying off has spread from an area maybe 50cm2 to an area 3m2 (some is completely bare other parts you can see the dead leave underneath and a thing covering of green on top) and other patches have appeared in both my front and back yard. I have been regularly watering and in the last week we have had 31mm of rain spread out through the week so I am positive this is not a lack of water issue. I also regularly sprinkle lawn grub and beetle pellets, this along with the size of the patches makes me think that the issue isn’t that. I believe the problem is a fungus or a type of lawn disease.

I live out of town so it not likely that this has spread from a neighbours place. As we had to go out of town last week we had a yard care person come out and mow the lawn. We suspect that whatever thus fungus is has come in via their mover blades (though we can’t prove that). This extensive die off has happened in this week.

In my research online I have identified Pythian Blight as the possible issue given the local high temperatures, the recent rain (and my watering) and the fertiliser (Multi Grow) which I have been sprinkling around in the hopes of encouraging the surrounding lawn to grow out the fill the gap. These are all listed online as conditions which allow Pythium to thrive. Ryegrass is also very susceptible to attack from Pythium and seems to be the first grasses to die off. One thing we don’t have which is associated with Pythium Blight is a greasy or slimy texture to the lawn and in some instances a whitish mould like covering. So even though we think this is our problem we are not 100% that it’s not something else.

We spoke to someone at one of the local turf farms and he said that to treat Pythium they mix a 50/50 Dettol and Water solution which kills the fungus straight off but leaves the grass unharmed. He told up to spay up the 300mm out from the edge of the patches and then also inside. We sprayed this on yesterday afternoon and then had to go into town. When we returned in the evening we noticed that the grass that had been sprayed was all discolouring to a brown/grey colour and the tops of the Oxalys has gone crispy. I wouldn’t mind if it killed the Oxalys but it also looks to have killed off what green lawn there was in the bare patches. And to just make it all worse today was an open home day so it all just looked horrible, dead patches with brown grass, smelling of Dettol.

I was hoping that someone may have some experience with this, recognise the symptoms and identify what has happened. And if anyone can offer some suggestions or advice on how to recover my lawn as soon as possible it would be much appreciated.

I have attached some images below to illustrate the problem and what has happened since we tried to treat it.

This is my lawn out the back last month. Lush and beautiful

The lawn yesterday before we ‘treated it’ with Dettol – This is the same area which is in the foreground of the first image

Detail of the dead areas – pre Dettol treatment

Detail of the green on top but it has died underneath – pre Dettol treatment

This is the same area today. It might have killed the fungus, I don’t know, but it seems to have killed of the lawn as well.

The green patches are still there but they are not as visible. They seems to have taken on a slightly darker colour but now the yellow is so prominent I’m worried that these green patches are actually dying.

The transition between the dead lawn, the live lawn which was sprayed and the live lawn which wasn’t sprayed

For a start I’m no kikuyu lover and don’t be surprised if I suddenly start raving and ranting. However I’ll begin by using someone else’s words.
“If you’re wondering about reasons for dying grass and how to revive a dead lawn, there are numerous possible causes and no easy answers. The first step to brown lawn care is figuring out why it happens in most cases.”
Then I could suggest that picking one culprit and going gung ho with dettol doesn’t seem to match at all with the above statement. I shudder at the thought of 50% dettol.
If you suspect Pythium; http://nuturf.com.au/problem/pythium-leaf-blight-damping-off/
Didn’t see any dettol on their list.

pH is always an importan aspect to keep on top of. Have you measured this in different sections of the lawn area? Always keep pH in mind whist attempting to apply any chemical changes.

“A range of hospital disinfectants were assessed in vitro by Vanachter et al. (1991) for the control of a range of tomato pathogens and compared with formaldehyde. They found that Amocid® (180 g/1 sodium-ortho- phenyl-phenolate) was better than formaldehyde for the inhibition of growth and toxicity to Fusarium oxysporum f.sp. radicis lycopersici, Didymella lycopersici, Phytophthora nicotianae var parasitica, a Pythium sp. and Clavibacter michiganense. Vanachter et al (1991) found that other disinfectants such as Dettol®, chlorhexidine, and chloramine T had good bactericidal properties but were less effective against fungi.”
You’ll find out a lot by downloading this document and searching all instances of Pythium in the document.
https://www.ngia.com.au/Attachment?Action=Download&Attachment_id=1226

Trees and lawns are a difficult dance to learn the steps of. Grasses and trees use available water differently. In dry times never is this more evident. Tree leaves also decomopose differently to lawn clippings, which may be why you can see some people raking up the leaves before mowing. Thatching is a common problem which can be caused by mowing fallen leaves.

I see you also use a sprinkler. Probably the worst way to water a lawn in warmer weather.
Australia isn’t the native home to most of the stuff I can see planted in your garden.
I can also note that no application of companion planting awareness is evident.

Starting to rant here.. Why mix kikuyu and buffalo? Why put ryegrass with that? I believe you are asking for trouble.

No science can be done unless we know more. Location, soil types for a start. I see you say Central West NSW. That’s a big place. You could say that I also live there. Saline conditions usually worsen during dry spells, particularly in the case of lawns. Oxalis sours the soil and as such is inadvisable in lawns that one wishes to be verdant. There are also many species of Oxalis so it would be wise to know which types.

Choosing species of trees that are good companions for lawns is also a wise move. Many trees will suck all the surface water and different genera can introduce various unwanted lawn pathogens.

Now I am really ranting kill the lawn rip it up and start again, preferrably after doing more research into most of what has been mentioned above.

https://www.gardeningknowhow.com/lawn-care/lgen/reasons-for-dying-grass.htm

The 50/50 Dettol mix was used solely becasue it was recommended by the guy at one of the turf farms. Needless to say I will never be buying turf from him in the future.

The lawn mix was in place when we bought the place 25 years ago. Whether you like the mix or not, we have always had lush lawns and never had an issue of this type in the past. As I mentioned, our house is listed for sale so wholesale replacing the turf is something the future owner can consider if they feel as passionately about this as you do. I regularly spray the Oxalys (yellow flowing don’t know the type) and there is very little of it in the lawn so I do not expect it to be much of an issue.

You mentioned “I see you also use a sprinkler. Probably the worst way to water a lawn in warmer weather.” What would you suggest instead? I live near Dubbo so the temperatures are very high and dry. I also mentioned before that we live out of town. We are not on town water. We do not have high water pressure so by necessity we need to use wobbler sprinklers over a long period of time. Soaker hoses do not work and pop up sprinkler are not an option.

I have already read the page you provided a link to. I am intimately familiar with the environmental conditions at my place so I can confidently narrow the issues down to a fungus with the help of the Dettol mixture. My focus must now turned to recovering the lawn over the next couple of weeks before the next open home. Any help in that regard would be appreciated.

Ned said:

The 50/50 Dettol mix was used solely becasue it was recommended by the guy at one of the turf farms. Needless to say I will never be buying turf from him in the future.

The lawn mix was in place when we bought the place 25 years ago. Whether you like the mix or not, we have always had lush lawns and never had an issue of this type in the past. As I mentioned, our house is listed for sale so wholesale replacing the turf is something the future owner can consider if they feel as passionately about this as you do. I regularly spray the Oxalys (yellow flowing don’t know the type) and there is very little of it in the lawn so I do not expect it to be much of an issue.

You mentioned “I see you also use a sprinkler. Probably the worst way to water a lawn in warmer weather.” What would you suggest instead? I live near Dubbo so the temperatures are very high and dry. I also mentioned before that we live out of town. We are not on town water. We do not have high water pressure so by necessity we need to use wobbler sprinklers over a long period of time. Soaker hoses do not work and pop up sprinkler are not an option.

I have already read the page you provided a link to. I am intimately familiar with the environmental conditions at my place so I can confidently narrow the issues down to a fungus with the help of the Dettol mixture. My focus must now turned to recovering the lawn over the next couple of weeks before the next open home. Any help in that regard would be appreciated.

Why have a lawn at all if you don’t have water?
Anyway my suggestion doesn’t require pressure. Only requires a head. If you have an above ground tank leave the hose to soak an area before moving it.

Don’t take my advice if you don’t want to but research linked in my post states that Dettol isn’t useful against fungi. You’d be better off with vinegar.

What do you spray the oxalis with?

Why have a lawn at all if you don’t have water?

We have plenty of water just not at high pressure. Having the lawn lush and green has never been a problem before and is definitely unrelated to our water availability. It is not possible to use that method on all our lawn but I will try it on the affected areas and see how that goes. Thanks

I think I’ve used Kamba M on the Oxalis, but it has mostly been treated by a horticulturalist who does some work in our orchard. He treats it regularly and has something that is stronger than the Kamba but I’m not sure what he uses.

Ned said:

bq. Why have a lawn at all if you don’t have water?

We have plenty of water just not at high pressure. Having the lawn lush and green has never been a problem before and is definitely unrelated to our water availability. It is not possible to use that method on all our lawn but I will try it on the affected areas and see how that goes. Thanks

I think I’ve used Kamba M on the Oxalis, but it has mostly been treated by a horticulturalist who does some work in our orchard. He treats it regularly and has something that is stronger than the Kamba but I’m not sure what he uses.

Kamba M is basically 2, 4-D. Which can come in various strengths.

Yes. deep soaking will assist regrowth around the sad areas of your lawns.