8 Common Rose Diseases and How to Treat Them

There’s nothing quite as stunning as a perfectly manicured rose garden throughout the spring and fall. But while you can expect your roses to develop into a beautiful garden, the truth is that getting them there can take a bit of work.

But the first sign of distress can be a little overwhelming, especially if you don’t know what’s going on and how to treat it. That’s why we decided to highlight some of the most common rose diseases here, before diving into the best products out there to treat them.

If you keep reading and treat your rose bushes properly, then you’ll have them back to presenting those signature blooms in no time!

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8 Common Rose Diseases

If you’re looking to keep your roses healthy then you need to be able to identify the most common rose diseases. That’s why we took the time to highlight eight of the most common rose diseases here, so keep reading to find out more.

Black Spot

Black spot is one of the most common rose diseases out there, but just because it’s common doesn’t mean that it’s not extremely serious. Black spot comes about after extended periods of wet weather in a warm climate, and if you leave it untreated it can take out your entire rose bush in no time.

Black Spot looks just like the name makes it sound like, as it presents itself as black spots about ½” in diameter around the leaves. If you have a severely infected plant, you should remove the infested canes and leaves, but for newer and milder infestations you can use a fungicide to get it under control.

Powdery Mildew

Powdery mildew is one of the most common fungal diseases to infect plants, and roses are far from immune. Powdery mildew spreads via the air from spores, making it nearly impossible to stop once it takes root in your garden or landscape.

Once you notice powdery mildew on your plants, it’s essential to treat all the plants in your landscape to prevent it from spreading. And since it spreads via airborne particles, your plant doesn’t even need to be near an infected one to get it!

Like most fungal infections powdery mildew thrives in wet conditions, so you’re more likely to notice it taking root on our plants if they remain wet for an extended period.

Compared to many other fungal diseases, powdery mildew doesn’t do much to the plant, but it does prevent it from getting enough sunlight to properly grow and thrive!

Cankers

Few fungal diseases on your rose bushes are as unsightly as cankers. Cankers typically leave the actual rose heads alone, but if you don’t treat them, they can prevent the development of the heads altogether.

A common cause of canker is using dirty prunes from plant to plant, but that’s not always the case. Keep in mind that while cankers can be an extremely challenging problem to solve, it’s also one of the easiest to prevent.

Simply use clean prunes, and mulch your rose bushes roots to prevent them from getting too cold during the winter. Follow these two simple steps, and you should be able to put your canker rose bush woes behind you in no time!

Botrytis Blight

Botrytis blight is one of the most frustrating and disappointing diseases that can afflict your rose bush. That’s because there are often no outward signs that your plant has any problems until the flowers start to bloom.

But when that happens, the flowers will turn brown and wilt, which completely ruins the beautiful appearance of the flowers. Botrytis Blight often occurs in hot and humid temperatures, but there are a few tricks you can try to keep it from cropping up in the first place.

Try skipping feedings in the summer to reduce the nitrogen levels in the soil, which blight thrives off of. Also, keep in mind that if you live in an area with plenty of sunny and dry weather, you shouldn’t have to worry about blight taking root.

However, if you find your rose bushes do have blight, you can treat them with a fungicide for a little while. But one of the most frustrating parts of dealing with blight in your rose garden is that over time it will develop a resistance to these fungicides.

If this happens, you’re either stuck with finding a new fungicide, or you end up writing the plants off entirely. So, if you’re dealing with blight in your garden, it’s important to address the root cause instead of just treating the symptoms if you want to keep your rose bushes healthy and thriving year after year.

Rose Rosette

Rose Rosette can come to afflict your plant by the wayward bite of a mite. Because of this one of the best ways to prevent Rose Rosette from taking root in the first place is with a miticide product. However, if you’re unfortunate enough to have a rose bush with Rose Rosette, you won’t be able to miss its distinct appearance.

The leaves turn brittle and develop a red or yellow pigmentation, and over time they develop bright red shoots as the size of the leaves shrink. The number of thorns will rapidly increase, and your rose bush will start to lose its distinctive appearance.

Sure, it’ll still bloom, but not as often and it simply won’t look right. Rose Rosette twists the natural beauty of the rose in a way that it’s still recognizable, but you can just tell that something’s not right. If your rose bush already has Rose Rosette, you’re out of luck.

There’s no bringing a plant back once it’s infected, and you need to remove it as quickly as possible to prevent the disease from spreading to other plants in your garden and killing them too.

Rust

Rust is a fungal infection that’s relatively common among roses. Rust gets its name from its signature appearance of brown or yellow spots, which look like rust forming on the leaves. You’ll notice these spots all over the plant, as the only area you won’t find them is on the roots and petals.

Having your rose plants in an area with plenty of circulation is the best way to prevent rust, but once it takes root, you need to apply a fungicide to keep it from spreading. For badly affected plants, the best thing you can do is simply remove the affected portions of the plant and provide a fungicide over the rest.

Rose Mosaic

While Rose Mosaic might sound like a beautiful name, it’s not something you want growing on your prized rose bushes. Rose Mosaic presents itself as wavy yellow lines or spots, and it will mottle the leaves as it spreads.

While Rose Mosaic typically won’t kill your plant all on its own, it will weaken the overall integrity of the plant. This means it won’t be able to respond to other stressors as well, and over time this will cause your plants to not to look as healthy, and can eventually kill them.

While Rose Mosaic might not seem like a big deal, one of the worst parts is that there’s no way to really treat it. If your rose bush has Rose Mosaic, you need to remove the infected plant before it has a chance to spread.

Because while Rose Mosaic spreads slowly, eventually it will spread, and then you’ll have to remove all of the rose bushes in your garden.

Crown Gall

Crown Gall is the last rose disease to make our list, and it’s a bacterial infection that you want to keep far away from your rose bushes. Crown Gall looks like no other rose disease, as it grows large woody growths on the stems of your rose bush.

These galls rob nutrients like water from reaching the top of your plant, which can weaken and prevent the top of the plant from blooming and continuing to grow.

Crown Gall spreads through direct contact, so it’s generally a relatively easy problem to take care of as long as you take all the proper precautions. This means removing the infected plant, as well as all of the surrounding soil.

After removing the rose bush you need to thoroughly disinfect all of the tools in a solution of 0.5 percent bleach for 10 to 15 minutes. Otherwise, the next time you go to use the tools, you’ll spread Crown Gall to those plants, and you’ll wind up right back where you started!

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5 Best Rose Disease Fungicides

Now that you know how to identify some of the most common rose diseases out there, it’s time to learn how to take care of them. Below are the five best rose disease fungicides you can use in your garden to clear up infestations fast to get your rose bushes back on track!

1. BioAdvanced 701290B Insecticide, Fungicide, and Miticide – Best Overall

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Application Style: Ready-to-use direct spray

Size: 24 or 32 ounces

Coverage Area: 45 plants

Reapplication Schedule: 30 days

If you’re serious about getting rid of rose diseases, but don’t want to use a complicated product, then BioAdvanced 701290B Insecticide, Fungicide, and Miticide is exactly what you need. It’s extremely easy to use, comes in multiple sizes, and it’s affordable too!

All you need to do to use this 3-in-1 product is point it at the plant you’re trying to protect and spray – it couldn’t be any easier. As the name implies, this product can take out any kind of fungal disease that hits your rose bushes, and it’ll also protect them from harmful insects and mites.

However, you’ll need to reapply it every 30 days to get sustained results, and it doesn’t have the largest coverage area compared to concentrated formulas. Still, with how easy it is to use and how affordable it is, it’s hard to go wrong with it, unless you have a ton of rose bushes.

Pros

• Easy to use
• Multiple size options
• Covers a ton of plants
• Very affordable
• 3-in-1 product

Cons

• Not the largest coverage area

2. BioAdvanced 701260B All in 1 Rose Care – Best Budget

[lasso ref=”bioadvanced-701260b-32oz-all-in-1-rose-care-32-oz-concentrate” id=”3693″ link_id=”2715″]

Application Style: Concentrate

Size: 32 ounces

Coverage Area: 192 square feet

Reapplication Schedule: Six weeks

Furthermore, this formula lasts a full six weeks, which is longer than any other product on our list. But none of this would matter if it didn’t do a great job at eliminating fungicides and another rose disease. Luckily for all of us, it’s an extremely effective formula that can keep your plant healthy.

Even better, it also provides plant food, so it’s the only product you need to apply to your rose bush to get phenomenal results. However, while there are tons of things to love about this product, there are two drawbacks.

First, it’s not an organic product. Second, you need to mix it up yourself to get the best results. It’s not a huge deal, but it’s one more step you need to complete before you can apply it to your rose bushes.

Pros

• Large coverage area
• Very affordable
• Long-lasting formula
• Provides rainproof protection
• Does an outstanding job at preventing diseases
• Also provides plant food

Cons

• Not an organic product
• You need to mix it yourself

3. Bonide 811 Copper 4E Fungicide – Best Organic Fungicide

[lasso ref=”bonide-811-copper-4e-fungicide-16oz-473ml” id=”3075″ link_id=”2716″]

Application Style: Concentrate – hose-end sprayer or tank sprayer

Size: 16 ounces

Coverage Area: 750 square feet

Reapplication Schedule: 10 days

Whether you’re applying your fungicide near your garden or if you’re simply looking for a product that’s better for the environment, then Bonide 811 Copper 4E Fungicide is an outstanding choice.

This fungicide is 100% organic, and it’s completely safe around pets and children. And while organic products have a bad reputation for not being as effective as non-organic choices, that’s simply not the case with Bonide.

It’s extremely effective, and it’s surprisingly affordable for what you get. Because not only is it extremely effective, but it has a very large coverage area for each bottle.

However, the real thing you notice by going with an organic product is that you’ll need to reapply it more often, and it only acts as a fungicide. You need to reapply this fungicide every ten days, which is about three times more often than its next closest non-organic competition.

Pros

• Completely organic
• Very large coverage area
• Affordable option for what you get
• Safe around people and pets
• Very effective formula

Cons

• You need to reapply it more often
• Only acts as a fungicide
• Needs to be mixed yourself

4. BioAdvanced 701262 All-in-One Rose and Flower Care – Premium Choice

[lasso ref=”bioadvanced-701262-all-in-one-rose-and-flower-care-plant-fertilizer-insect-killer-and-fungicide-64-ounce-concentrate” id=”3694″ link_id=”2717″]

Application Style: Concentrate

Size: 64 ounces

Coverage Area: 384 square feet

Reapplication Schedule: 6 weeks

For starters, it has a large application area, which helps offset the higher upfront cost – but not completely. Another perk is that you only need to reapply it once every six weeks, and that means that your bottle will last longer than other products too.

But while it’s certainly going to go a long way, it’s the extra perks that really help set it apart. First, it’s extremely effective at killing off various rose diseases, but that’s not all it does. It also acts as an insecticide, which is a pretty big deal when you’re dealing with multiple problems at once.

Second, this fungicide is also completely rainproof after the initial application, and that keeps your plants’ safe longer. However, not only is it a more expensive option, but you also need to mix it yourself before you apply it.

Pros

• Very large application area
• You don’t need to reapply it very often
• Insect and disease control applications
• Rainproof design
• Very effective formula

Cons

• More expensive option
• You need to mix it yourself

5. Ortho Rose & Flower Disease Control Concentrate – Runner Up Choice

[lasso ref=”ortho-rose-flower-disease-control-concentrate-16-oz” id=”3695″ link_id=”2718″]

Application Style: Concentrate

Size: 16 ounces

Coverage Area: 60 plants

Reapplication Schedule: 4 weeks

Even better, it starts working after just 24 hours, and it has a rainproof formula after the initial application. And since you only need to reapply it once every four weeks, a single bottle can last you quite some time.

However, it is our runner-up choice for a reason. To begin with, you’ll need to mix it up yourself. From there, it only comes in a smaller bottle option, which means you’ll need to replace it more often.

Finally, what really drops it to the bottom of our list is that it’s a more expensive choice per ounce. While it’s not the most expensive upfront, since it comes in a much smaller size you might find yourself spending more in the long run, compared to if you went with a different option to begin with!

Pros

• Very effective formula
• Decent reapplication schedule
• Starts working in only 24 hours
• Rainproof formula

Cons

• You need to mix it yourself
• Only comes in a smaller bottle
• More expensive per ounce/not the largest coverage area

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Final Thoughts

If you’re combating common rose diseases it can feel like a struggle to get everything under control. But once you learn some common practices, how to identify the diseases, and some of the best treatment options, you can make fighting common rose diseases a thing of the past!

So just because you’re dealing with a frustrating disease now, don’t let it deter you from growing more roses in the future!

FAQ

Even after you’ve read about the different rose bush diseases and their potential treatment options, it’s only natural to have a few questions. That’s why we decided to answer some of the most frequently asked questions for you here.