What’s the white fluffy stuff on my lawn in the morning?
Amy idea on what is causing this and how to get rid of it? Seems like a lawn fungus?
Comments · 8
Want to like, comment or start a new discussion? Join us in the app.
Open the NZLA App →
That white cottony webbing across the blades is fungal mycelium. That bit can be a little misleading on its own, because dollar spot throws out mycelium too and the two can look similar on a damp morning. But given the time of year, cold and wet heading into winter, I'd say this is almost definitely Fusarium, also called Microdochium patch, or the early stages of it. You'll find the mycelium disappears as the sun hits it in the morning, but it'll be back overnight.
What causes it is pretty simple. It's a cold weather disease that gets going when the grass stays wet and the air sits still. Long dewy mornings, shade, poor drainage, no airflow, and soft growth from a late hit of nitrogen, especially common with people using fast release fertilisers late in the season.
First, fix the conditions. Knock the dew off in the mornings, even just dragging a hose or a brush across the lawn makes a difference because you're getting the leaf to dry faster. Hopefully you're not watering at night, you should hardly be watering at all this time of the year.
A lot of people make the mistake of throwing nitrogen at it, that isn't the best idea this time of the year. If you've had a late hit of fast release on it, that combined with the conditions would do it. Honestly avoid fast release fertiliser it's garbage and causes more problems than it solves.
For control, get Fungus Pro on as soon as you can. It's a contact, so it knocks the mycelium down where it touches it and protects the healthy grass around the patch straight away, and with Fusarium the sooner you get onto it the better. Leave the Fungus Pro on the surface for a few days after application. No irrigation, once it's washed off its useless as it's a contact fungicide.
Then consider an application of Azoxy (it can be applied in the tank with the Fungus Pro). That one's systemic, so it moves into the plant and provides 28 days preventative protection.
Disease pressure will drop off considerably once you've had some frosts. You also need to sharpen your mower blades, although pushing soft growth this time of the year and you’ll shred the leaf when cutting.
@Jonny Hicks appreciate this post as I found mycelium yesterday for the first time so was great to read this post. Here was me thinking how good the Auckland weather had been but still issues!
@Tessa Larsen I seen your post in your journal, definitely more advanced than this example and almost definitely Fusarium. I'd have a read of my fertiliser post I put up a couple of days ago.
@Jonny Hicks will do thx
@Jonny Hicks does HOC make a difference, especially having ETF with little to no sun this time of year.
@Jonny Hicks I’m not expecting any frost on my lawn in Auckland and my lawns are ‘boxed in’ with fences and buildings, almost no airflow at grass level.
@George A Cutting ETF too short is one of the things that does increase disease pressure, yes. It’s capable of being mowed shorter than most people think, but this time of year that’s not where you want it. The grass is already slowing down, and dropping the height adds stress on top of that.
@Jonny Hicks thanks, will keep it at 45mm and keep feeding it when I need to.