How To Identify And Treat Lawn Rust (Fungus On Grass)

Do you have orange grass? Does your lawn look like it has a disease? Maybe it seems to be coated with orange-red or yellowish dust?

Well it is likely that you have lawn rust, which is a type of fungus that grows on grass.

But don't panic just yet... it is quite treatable and your lawn will likely recover from lawn rust. Let's take a look at how to properly identify this fungus, and what you can do about it if your grass has it.

What is Lawn Rust and what Causes it?

Lawn rust is a fungal disease that affect turf grasses.

It is usually prevalent in later summer/early fall when the lawns growth is quite slow.

Dry weather and lack of nitrogen can also be factors that lead the lawn rust growing.

Identification of Rust Fungus on Grass

Identification of rust fungus on grass is quite easy and it just requires looking for a few easy to spot signs.

Look for these signs:

Grass blades are coated in an orange-red to yellow/brown dust or spores that resembles rust
You will be able to rub the dust off with your fingers
You may notice orange or yellow powder/discoloration of your shoes after walking on the affected grass
If the lawn rust has gone untreated for some time then you may notice raised pustules
Affected patches of lawn will generally become thin and weak

Images of Lawn Rust

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Problems Caused By Lawn Rust

Overall, grass rust fungus is not a huge problem so don't stress if you have noticed it on your lawn.

Some of the minor problems that rust fungus does cause includes:

Reduces the ability for the grass to photosynthesize
Lawn will look less healthy
Grass growth will slow down
Lawn eventually become weak and will be damaged easily
The dust will cling to shoes,clothes and garden equipment and may stain

How to Treat Lawn Rust

Usually lawn rust can be treated without the need to resort to chemicals or fungicides.

So first, let's take a look at the non-chemical ways to treat rust fungus on your lawns:

Fertilize

Fertilizing your lawn is the best way to treat lawn fungus. Regular fertilizing of your lawn will encourage the grass to grow faster, slow growing grass gives the disease lots of time to develop and entrench itself in your lawn.

We recommend a nitrogen rich fertilizer such as Scotts. See why we recommend Scotts fertilizer here.

Water In The Mornings

Watering your lawn in the mornings gives it time to dry out during the day, which will help discourage further lawn rust growth.

Watering regularly also assists your grass to grow quickly, thus discouraging further lawn fungus growth.

Mow Regularly

Mowing the lawn regularly cuts off the top layer of lawn rust fungus and allows the remaining grass to get proper air circulation - reducing the amount of time the grass stays we for which in turn reduces the amount of lawn rust that can grow.

It is also recommended to always use a mower with a grass catcher so that the left over clippings aren't left on the grass, negating the effects of mowing. If you don't have a mower with a grass catcher, then rake up the clippings and dispose of.

Also ensure that your equipment is washed down properly after mowing to remove any left over rust dust.

Looking for a good cordless mower? Check out this post.

Using Fungicides To Kill Lawn Rust

Using Fungicides to kill lawn rust is usually not necessary, and due to the fact that most fungicides contain toxic chemicals we recommend using this method only when the previous three have failed.

If you do need to use a fungicide to control a particularly bad outbreak of lawn fungus, then you can use something like Scotts Lawn Fungus Control.

Be sure to follow the instructions of your chosen fungicide carefully.

Lawn Rust FAQ

Is lawn rust harmful to pets?

No, lawn rust is nor harmful to pets. You may however find that they get a bit of an orange tinge to their coat!

Is grass rust harmful to humans?

No, grass rust is not at all harmful to humans.