Lawn Fusarium

fusarium close up1


Lawn Fusarium

The disease fusarium may not be as widespread as our main disease, red thread – but it is far more deadly. So, when you’re caring for lawns, you need to be vigilant.

What is lawn fusarium?

fusarium close up 1

Fusarium is a family of fungi that live in soil and can attack plants. Lawn fusarium, or Snow Mould (because of its appearance – see photo) is a fungal turf disease and can attack many types of grass areas, from sports surfaces to treated lawns.  

Is fusarium a sign of a poor lawn?

Not at all.  This disease is a problem on sports surfaces across the world under certain conditions, and, ironically, this is because of the intensive care they receive. So, if we mimic this kind of care with our garden lawns – for example, watering when it’s not really necessary, feeding a lot more than normal and cutting very short – the stressed plants become more susceptible to a fusarium attack.

Which grasses do fusarium affect?

Fusarium takes no sides and will affect most grass species.  Vulnerability is more often to do with how healthy the grass is and whether it can withstand an attack.

Will lawn fusarium kill my grass?

Once the disease spreads from the leaf to the crown of the plant, the answer is a definite ‘Yes’.  And without vigilance and swift action it can spread very quickly too. 

fusarium on golf green 1
Characteristics fusarium circles, here on a golf green

When does lawn fusarium appear?

Fusarium traditionally thrives in the colder months between September and March. However, as with red thread, fusarium can appear almost any time of the year if our changeable weather permits it. It is at its most dangerous, however, during Winter when a) the grass plant is already under stress from the cold and wet environment, b) daylight hours are fewer, and c) there is the likelihood of extreme weather such as floods and snow.

Can I prevent fusarium from coming?

To a point, the best you can do is manage your lawn well as a healthy lawn can better fight the disease. And your best friend is your soil. Improving the soil bacteria levels (with soil conditioners, aeration etc) should increase the soil fungi that can and will attack the disease pathogen.  Fighting it with fungicides when it appears is fine, but prevention is better than cure, and so soil biology works best in the long run (see more below).

Can I make fusarium worse?

You can certainly make it worse, and dangerously quickly too. You can easily spread spores with feet and even animals, and especially by mowing, so refrain from that until some control has been made.

walking on grass

How do I treat lawn fusarium?

The best plan is to look at soil biology, but in a simple way.  Are you making best use of your soils?  Are you aerating them correctly and efficiently?  Do you add anything at all to enhance the soil bacteria and microbes?  You should give your lawn soils the same degree of care as soil in other parts of your garden. The use of organic feeds and soil conditioners is a simple way to do this.

Beyond looking after your soil, the one thing you mustn’t do if you have fusarium is to ignore it. During times of extreme weather, where your lawn may be under stress, diligence is critical and can save your lawn from becoming a mess.  There are a number of easy steps you can do which can help, but won’t cure. 

Moisture: The disease spores thrive on moisture so drying the lawn out as quickly as you can, can help slow it spreading. Knocking the morning dew off the grass is a way to help dry the plant out during winter months.  This can be done with a broom, a small blower and even a piece of hosepipe in between two ride-on mowers if your lawn is big enough. 

Thatch: Keep on top of your thatch levels.  You can slow the spread by ensuring rainfall gets through your lawn quickly rather creating a cold, wet thatch layer.

Mowing: If you do have to mow, refrain from using a roller mower so that you lessen the chance of it being spread.  This is actually a sensible mowing practice for winter, not just for disease control.

Ferrous sulphate: Don’t forget our good friend, ferrous sulphate.  That’s right, our simple, organic friend can come to the rescue again!  A spray of this product can slow and to some extent, stop the disease in its tracks.  And it simply does this by ‘drying’ the leaf blades out, thus possibly giving some respite to prevent the disease from worsening.

Fungicides: And last but not least is a simple fungicide treatment, professionally applied.  However, don’t think this will be an absolute cure.  Given the right conditions, it can and should work, but as some of our best sports venues will confirm, funguses can get resistant to fungicides even. 


Become a member and receive news of our e-learning modules and our professional courses.