How to Identify and Treat Rose Rust

Phragmidium spp.

Some years, I step outside and notice some sort of problem developing on my roses, and I ask myself why I bother.

There are much easier plants to grow, right? Then I cut some of my favorite flowers and bring them inside, and I remember why it’s all worth it.

A close up vertical image of a hand from the bottom of the frame holding the foliage of a rose that is suffering from rust. To the top and bottom of the frame is green and white printed text.

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Rose rust is one of those diseases that makes me question my dedication to roses. I live in an area where it’s a matter of when, not if, I’ll be dealing with fungal issues.

When those tell-tale orange spores pop up, I know I let my care routine slip, and it’s time to step it back up.

Rust can be prevented, to some degree, but it’s pretty hard to eradicate. Better yet, there are many resistant options out there.

It used to be that rust mostly stuck to warm, humid areas like the Southern US and the Pacific Coast states. But as the climate changes and previously frigid areas experience warmer winters, it’s taking hold in more areas.

In some coastal areas, it’s a chronic issue that growers will deal with year after year. In this guide, we’re going to do our best to help you keep this fungal issue out of your garden.

If it does come calling, we’ll also help you deal with it. Here’s what we’re going to go over to make that happen:

If you’re already dealing with rust, my condolences. You’re probably eager to figure out what you need to do, so let’s not wait one minute more:

What Is Rose Rust?

Rose rust is caused by several species of fungi in the Phragmidium genus.

The fungi in this genus only infect roses, so you don’t have to worry about the other plants in your garden coming down with this disease.

If you wanted to totally eradicate this disease, all you’d have to do is tear out all your roses and wait for a few years. The fungus would die because it doesn’t have a host.

A close up horizontal image of rust disease under high magnification.

Rose rust spreads through the air and on water, so it’s pretty hard to prevent it from moving about a garden, since we can’t control the wind and rain.

Temperatures need to be around 65 to 70°F for the spores to actually infect the plant.

More importantly for our purposes, there needs to be moisture present on the leaves for at least two hours for infection to take place.

Symptoms

This disease looks like the typical rust you’ll see on many other species. It manifests as round, blackish-brown spots with orange, tan, or yellow centers.

The leaf itself might turn yellow, as well. If you turn the leaf over, you’ll see orange fungal spores. They look kind of like orange powder clustered together.

A close up horizontal image of foliage showing symptoms of rust, a fungal infection.

Usually, foliage on the bottom of the plant succumbs first, and then the disease moves its way up the plant. In the fall, the leaves will develop black spores.

You might also see galls and lesions on the canes.

It rarely kills a plant, but the disease can cause complete defoliation. When a plant is defoliated, it can’t produce and store up energy, which means poor growth and definitely no flowers.

Prevention

Since the spores spread in the air and in water, your job is to try to reduce the chances that the spores will be able to travel around from plant to plant.

As I said, in some areas, just expect to be dealing with rust to some degree every year. But that doesn’t mean it needs to spread like wildfire or seriously damage your plants.

A close up horizontal image of a gardener using a pair of secateurs to prune the branch of a shrub.

Prevention can go a long way.

Remember, this plant likes moderate temperatures and lots of moisture. So when spring and fall come around, it’s time to start being vigilant. Keep your plants well pruned so that they’ll dry out more quickly after a rain.

A close up horizontal image of the symptoms of rust on foliage.
Photo by Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org.

When it comes to watering, only water at the soil level, not on the leaves. You should also water in the morning, so the plant has plenty of time to dry out.

When the right conditions are present for spreading the disease, break out the preventative fungicides.

Products containing sulfur, copper, mancozeb, or Bacillus subtilis all work as preventatives. You can also use hydrophobic neem oil.

There are even products out there labeled specifically for treating rose rust. That’s how prevalent this disease has become.

A close up of a bottle of Bonide Rose Rx 3 in 1 Concentrate isolated on a white background.

Bonide Rose Rx 3 in 1

Bonide’s Rose RX 3 in 1 contains neem oil and is available in 32 ounce ready to use and 16-ounce concentrates at Arbico Organics.

Spray every few weeks during wet weather, high humidity, and temperatures in the high 60s.

Finally, when working in the garden, be sure to clean your tools thoroughly between plants. You don’t want to prune one specimen that’s infected with rust and then take those pruners to an uninfected plant.

Treatment

You did your best, but rust got your roses anyway. Don’t feel bad, it happens to all of us.

The first thing you should do is prune off any symptomatic leaves. Then, pull out the fungicides.

Before you start spraying, know that you probably won’t ever get rid of the disease from the plant. Treatment will just reduce the symptoms and spread.

A close up horizontal image of a gardener using a spray bottle to apply fungicide to plants in the garden.

Use the same products as described above.

Unless you have a beloved plant that you don’t mind pampering year after year, seriously infected plants should be pulled and disposed of.

Resistant Cultivars

Since rust is part of our lives, now, planting resistant types can make your life much easier. Hybrids are more prone to rust, so avoid those.

Rugosas are nearly immune, so they’re perfect if you’re frequently struggling with this problem.

Boscobel

It took several double takes to convince myself that I wasn’t looking at a peony when I first saw ‘Boscobel.’

A close up horizontal image of two pink 'Boscobel' flowers growing in the garden pictured on a soft focus background.

This David Austin has cupped flowers so packed with petals that it’s not clear how they all fit. Initially, the buds on this plant are red before opening and transitioning to coral pink.

Carefree Delight

If a rose was ever appropriately named, it’s ‘Carefree Delight.’

A horizontal image of 'Carefree Delight' roses growing in the garden pictured on a soft focus background.

The continually blooming, single pink flowers on this shrub type will perform all season long with little input from you.

Cecil Brunner

This polyantha is part of the World Federation of Rose Societies’ Old Rose Hall of Fame.

It was bred in the late 1800s and continues to enjoy widespread popularity.

The heavily fragrant, pale pink flowers stick around for weeks and weeks, and the flushes will repeat throughout the summer and fall.

A close up square image of light pink 'Cecile Brunner' flowers pictured on a dark background.

‘Cecil Brunner’

Bring one home from Nature Hills Nursery.

Graham Thomas

‘Graham Thomas’ is a David Austin rose named for the acclaimed British breeder.

A close up horizontal image of yellow 'Graham Thomas' English roses growing in the garden pictured on a soft focus background.

It’s a climber that’s positively smothered in fully double, yellow blossoms that are faintly scented like violets.

A close up of an orange 'Graham Thomas' flower pictured on a soft focus background.

‘Graham Thomas’

Bring home this legendary type from Burpee as a bare root.

Livin’ Easy

Life is easy when you’re growing this repeat blooming floribunda with salmon-orange blossoms.

It’s pretty much immune to black spot and rust, so you can enjoy your summer basking in the sun rather than fussing over your plants.

A close up square image of a single red 'Livin' Easy' rose pictured in bright sunshine on a soft focus background.

‘Livin’ Easy’

Snag one in a #2 container from Nature Hills Nursery or grab it paired and trained as a tree with another disease-resistant rose, ‘Easy Going,’ at Fast Growing Trees.

New Year

Celebrate summer with the grandiflora ‘New Year.’

The golden-yellow double flowers bring instant cheer wherever they grow, and the fact that you don’t have to waste time spraying and pruning will make you feel more like celebrating.

Sexy Rexy

Mention ‘Sexy Rexy’ to a rosarian, and they’ll probably comment on how it’s one of the most floriferous roses they’ve ever seen. It’s a vigorous floribunda with classic pink blossoms.

A close up of light pink 'Sexy Rexy' flowers growing in the garden.

‘Sexy Rexy’

Add some color to your garden by purchasing one in a #2 container at Nature Hills Nursery.

Mr. Lincoln

‘Mr. Lincoln’ is so disease-resistant that, for a long time, it was the rootstock of choice for grafted roses.

The blood-red, double flowers on this hybrid tea are incomparable. That’s right, I know I said you should avoid hybrid teas, but this is the exception.

A close up square image of a single 'Mister Lincoln' flower pictured on a soft focus background.

‘Mr. Lincoln’

Nature Hills Nursery carries this tried-and-true toughy in #2 containers.

Peace

Some roses need no introduction. Rosarians will know exactly what you’re talking about when you mention ‘Peace.’

The orange and pink blossoms put noted breeder Meilland on the map, and it’s the standard that other roses are held to.

A close up square image of pink and yellow bicolored 'Peace' flowers growing in the garden pictured on a soft focus background.

‘Peace’

Bring some serenity to your yard by picking up a shrub from Fast Growing Trees.

Stop Rust From Ruining the Party

None of us want to deal with rust, but we don’t always get a say in the matter. Still, a little bit of knowledge goes a long way.

A close up horizontal image of rose foliage covered in the symptoms of a fungal disease known as rust, pictured on a soft focus background.

Are you struggling with rust this year? What kind of roses are you growing? Share your woes with us in the comments.

Are you still facing problems with your plants? Unfortunately, when a plant is suffering from one problem, it’s not unusual for other pests and diseases to join in.

We have a few guides to help you deal with issues on roses, if that’s the case:

Photo of author
Kristine Lofgren is a writer, photographer, reader, and gardening lover from outside Portland, Oregon. She was raised in the Utah desert, and made her way to the rainforests of the Pacific Northwest with her husband and two dogs in 2018. Her passion is focused these days on growing ornamental edibles, and foraging for food in the urban and suburban landscape.

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Gail Leachman
Gail Leachman (@guest_29533)
11 months ago

Very very very very very, helpful. Thank you for the ‘complete’ lesson which I will now adhere to as if, and it is, the law of caring for one’s roses.

Beverly
Beverly (@guest_29667)
11 months ago

What if I can’t burn or bury the infected branches?

Sarah Lancaster
Sarah Lancaster (@guest_30022)
11 months ago

My Mr Lincoln and Peace both have rust. 🤦🏻‍♀️ Still, there’s no way I’m pulling those gorgeous boys out, so I’ll have to get out the fungicide and baby them for the next few weeks until it dries out.

Krys
Krys (@guest_31160)
10 months ago

Would like to join this group!

Allison Sidhu
Allison Sidhu(@allison-sidhu)
Reply to  Krys
10 months ago

Thank you for being a part of a our community of readers! Feel free to follow us on social media.

RALPH COOPER
RALPH COOPER (@guest_31310)
10 months ago

What pesticide is effective on rust????

Allison Sidhu
Allison Sidhu(@allison-sidhu)
Reply to  RALPH COOPER
10 months ago

Pesticides are generally used to destroy insects, whereas a fungicide is what you’re after in the case of rust. Have you tried the suggestions provided above in our article? We recommend it!

Carol Johnson
Carol Johnson (@guest_31675)
10 months ago

I think I have lost my knock out roses. They were gorgeous in spring, so full. Am not an intense gardener… we had drought and then lots of rain. This seemed to happen over the past two months. So now I am applying fungicide…but maybe I should pull these out?

PXL_20230710_182841828.jpg
Carol Johnson
Carol Johnson (@guest_32054)
Reply to  Kristine Lofgren
9 months ago

Thank you. I have trimmed most of the bush. It is about 10-12 years old, so a lot of dead wood at the bottom. Will check out the guide.