Lawn Rust: How to Identify, Treat & Prevent This Common Lawn Fungus

When you first notice strange orange dust on your grass, it’s weird.

What is this, Mars?

Unless there was a mass Cheetos-munching party out on your lawn, the culprit is probably lawn rust disease, a lawn fungus that occasionally pops up in Minneapolis and Eau Claire.

What exactly is lawn rust disease? Will it kill your lawn? What should you do about it?

Let’s learn more about lawn rust disease, including:

• First, What Exactly is Lawn Rust Fungus?
• How to Identify Lawn Rust Disease
• Lawn Rust Causes: Why Does It Happen?
• Does Lawn Rust Fungus Spread?
• What Kind of Damage Does Lawn Rust Fungus Do?
• You Have the Orange Dust: Now What? How to Treat Lawn Rust
• How to Prevent Lawn Rust Disease

First, don’t panic. Yes, it looks kind of alarming, but lawn rust fungus is just one of several lawn diseases that pop up in damp, humid weather and tend to strike lawns that could use more nitrogen.

It won’t kill your grass, but it’s pretty unsightly, so you’ll want to take some steps to get rid of it, keep it from spreading, and nourish your lawn so it won’t be so susceptible to this orange lawn invader.

First, What Exactly is Lawn Rust Disease?

Lawn rust (Puccinia spp.) is a fungus, one of several lawn diseases in Minneapolis and Eau Claire that typically pop up in mid-summer through late fall, once your grass growth has slowed down from its late spring and early summer growth.

Lawn rust typically strikes Kentucky bluegrass and perennial ryegrass — two common turf types in Wisconsin and Minnesota.

How to Identify Lawn Rust Disease

There’s not much mystery here.

Lawn rust shows up as an orange or rust-colored powdery substance on your lawn. It’s easy to see. It can appear as spots or completely cover a grass blade.

In the early stages of lawn rust disease, you might notice your lawn looking light yellow. That’s not a great clue, as other issues can cause grass to turn yellowish. But soon you’ll notice that tell-tale orange powdery fungus.

And this orange dust on your grass sticks to everything.

You’ll notice it on your shoes or pants after you walk across your grass. On your dog’s paws after he romps around chasing squirrels. On your lawnmower after you mow.

Lawn rust fungus easily rubs off the grass and onto anything that comes in contact with it.

Which brings us to…

Does Lawn Rust Fungus Spread?

Unfortunately, yes. In a big way.

All those powdery orange spores, so readily brushed off your grass blades, are easily carried from blade to blade of grass by the wind, those shoes of yours, your dog’s paws.

That spreads the disease across your lawn.

Lawn Rust Causes: Why Does It Happen?

Lawn rust, like most lawn fungal diseases in Minneapolis and Eau Claire, loves warm, humid weather and shade. If your grass stays wet for too long, either because of extended rain, poor drainage in your yard, or somebody set the irrigation controller wrong, (nobody’s judging) lawn rust can take hold.

Cool nights? Heavy dew? Light, frequent rainfall? That’s a big welcome mat for lawn rust.

But lawn rust fungus also loves under-nourished turf, especially Wisconsin or Minnesota lawns that are low in nitrogen, which is vital for color and growth and promotes strong root development.

Lawn rust prefers lawns that are slow growing, which is why it typically shows up in late summer, when the summer heat has slowed your lawn’s growth.

What Kind of Damage Does Lawn Rust Fungus Do?

If the bad news is that your lawn is orange, the good news is that lawn rust disease doesn’t usually cause lasting damage to your lawn.

Yes, it’s frustrating that your lawn looks weird and unhealthy, but this orange invader will not kill it.

But it can weaken your grass and make it more susceptible to other problems.

You Have the Orange Dust: Now What? How to Treat Lawn Rust

If lawn rust fungus strikes toward the end of summer, as it usually does, the change of seasons might give it the boot.

The return of cooler fall temperatures and more rain encourages grass to grow faster. Remember, lawn rust disease likes slow-growing lawns.

When you head out to mow, your mower blade will take care of the rust for you, shearing it right off.

Want to speed up the process? Apply a quick-release, high-nitrogen fertilizer to help stimulate your lawn’s growth. Then, mow regularly to remove the rust-covered blades.

But don’t let those orange powdery clippings hang around. Rake them up and remove them to prevent the disease from spreading.

Wash your lawn mower after mowing fungus-covered grass, or you’ll spread the fungus the next time you mow.

You’ll not likely need a fungicide to get rid of your lawn rust fungus. This lawn fungus usually clears up on its own if you’re patient. And the grass typically comes back on its own after the fungus disappears.

Tips for Preventing Lawn Rust and Other Diseases

A healthy lawn is better equipped for trauma like lawn rust and other diseases.

• Fertilize your lawn in the fall and spring to keep it healthy and to give it a better chance of surviving lawn fungus.
• Aeration, aeration, aeration. You want to reduce compaction, reduce thatch, and improve your lawn’s drainage.
• Don’t water too often — you don’t want your lawn too wet.
• Water less frequently but for longer. When the roots have to dive deeper for moisture, your lawn develops a stronger, healthier root system. Your lawn needs about one inch of water each week.
• Water early in the day, before sunrise, so your lawn can fully dry before evening.
• Mow tall. You’ve heard it here before, and for good reason. Keep your grass height between 3 and 5 inches, and avoid mowing during wet weather. 

Mowing too short is like a welcome mat for lawn fungus. It weakens the grass and makes it more vulnerable to diseases.

Frustrated by Lawn Diseases? Call RainMaster

If your Minneapolis lawn is covered in orange powder, you can eat all the cheese puffs you want out there and not worry about the crumbs.

Better get, keep lawn rust fungus and other lawn diseases from creeping in by setting up your lawn for success with a proactive lawn care program that includes a custom nutrition plan and aeration.

The roots will be nourished, the soil packed with nutrients and able to drain better, and your lawn thick and healthy, so lawn diseases will have a harder time taking hold.

Also, consider a regular irrigation maintenance program to ensure your sprinkler system delivers the right amount of water at the right time so you're not encouraging lawn fungus.

Want to be confident about your choice of lawn care in Minneapolis, MN & Eau Claire, WI? Request a quote today! We’ll review your lawn care options together so you can make a great choice.

Image Sources | Lawn Rust, Lawn Rust 2