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Rose Black Spot

Diplocarpon rosae
Updated Apr 23, 2024
 
1

Make a Positive Identification

  • Rose black spot is a fungal disease that causes black spots on rose bush leaves and stems.
  • It causes leaves to turn yellow and fall off the bush.
  • Severely infected plants often look bare with few leaves and flowers.
Species: Black Spot
Rose foliage with black spots before leaves yellow

Signe Danler, Oregon State University

Look for brown-to-black spots forming on the leaves and stems in the spring.

Species: Black Spot
Mottled green and yellow leaf with black spots; the spots have diffuse edges

William Fountain, University of Kentucky, Bugwood.org (cropped)

Black spot can cause leaves to turn yellow and fall off. The black spots have diffuse edges as shown in the photo.

Species: Black Spot
Rose leaves with black spots joined along leaf veins

Signe Danler, Oregon State University

Spots may be unevenly distributed. They may follow the veins of the leaf.

Species: Black Spot
Sparse leaves on rose stems

Molly Hoffer, 1996, Oregon State University

Black spot defoliates rose bushes.This bush has few leaves to create energy the bush needs to live now and in winter.

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LOOK-ALIKE: DOWNY MILDEW
Species: Downy Mildew
Purple spots from downy mildew on rose leaf

Jean L. Williams-Woodward, University of Georgia, Bugwood.org

Downy mildew (Peronospora sparsa) is a fungal leaf disease. It causes purple spots on the upper leaf surface. Downy mildew spots have crisp, angular edges. In comparison, the spots caused by rose black spot have diffuse edges.

 
2

Rose Black Spot Benefits

  • Rose black spot is a plant disease that harms susceptible rose plants. It doesn’t have any benefit for people or the environment.
 

Rose Black Spot Risks

  • Rose black spot causes damage to leaves, stems, and flowers.
  • Rose bushes often lose many leaves during the growing season.
  • The plants may eventually die.
Risk Card
Does it cause harm?
Adults & Children
None
Property
Low
Pets
None
Annoyance
Some
Environment
None
Action Optional
 
3

TAKE ACTION?

Rose black spot affects the way rose plants look. Take action if you can’t tolerate the damage.

Do I need to take action?
If you don’t like how it looks, you will have to take action.

What if I do nothing?
Rose black spot weakens the plants.

NEED HELP?

Consider a licensed pest control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon  and other states  can suggest other methods.

 
4
HOW TO GET RID OF ROSE BLACK SPOT

Prevention

  • For new rose plantings, choose varieties that are resistant to black spot and other diseases. See Rose Cultivar Resistance  (PNW Plant Disease Management Handbook).
  • Prune established rose plantings to promote air flow. Good air flow lowers the conditions that favor plant diseases.

Non-chemical Methods

  • Remove stems, leaves, and flowers that show disease. Rake up fallen leaves to disrupt the disease’s life cycle.

Chemical Methods

  • Fungicides effectively control rose black spot when used according to the label instructions. Fungicides are pesticides that target fungal diseases on plants.
  • Check for application timing on the label. It may be hard to control black spot once plants develop disease symptoms. 

Jump To

Method Does it work? Is it safe? Recommendation
A
Pruning & Raking Leaves
Effective
Low risk
B
Control with Fungicides
Effective
Moderate risk
Use if Necessary
C
If Using Fungicides, Protect Yourself & Minimize Risks
D
PREVENT ROSE BLACK SPOT
 
A

Pruning & Raking Leaves

Non-Chemical Method

Signe Danler, Oregon State University

Pruning & Raking Leaves

Pruning to promote air flow and raking fallen leaves disrupts the rose black spot disease cycle.

Does it work?
Effective

These non-chemical strategies help minimize rose disease problems.

How much effort?
Moderate effort
What's the risk?
Low risk
Possible risk of exposure or harm from chemicals
NONE
Loppers cutting a rose cane

Signe Danler, Oregon State University

Prune roses to promote airflow. Thin out and space canes to open up the center of the shrub. This helps the leaves dry quickly after rain to reduce disease pressure. Avoid overhead watering.

Gloved hand pulling infected leaves from rose bush

Signe Danler, Oregon State University

Remove stems, leaves, and flowers that show disease to limit the spread.

Raking up black spot-infected leaves

Signe Danler, Oregon State University

Rake up and remove diseased leaves that fall to the ground. Dispose of diseased material in your debris bin, compost pile, or burn pile. Don’t use homemade compost that includes diseased rose material to amend the soil near your rose bushes.

 
B

Control with Fungicides

Chemical Method: Use with caution

iStock

Control with Fungicides

Use if Necessary
Does it work?
Effective

Fungicides effectively prevent rose black spot when used according to label directions.

How much effort?
Moderate effort
What's the risk?
Moderate risk
Possible risk of exposure or harm from chemicals
Using fungicides includes some amount of risk. The lowest risk comes without using fungicides.

You may be exposed to a fungicide if you:

  • Get it on your skin
  • Breathe it in
  • Eat or smoke afterward without washing hands
  • Touch or eat plants that are wet with spray (you, pets, or children)
  • Bring it inside on your shoes or clothes

Follow directions closely to reduce risk.

Some products are available for home use. A few are listed below. These active ingredients are suggested chemical treatments to control rose black spot. Look for these chemical names in the “Active Ingredients” section of product labels.

  • Bacillus amyloliquifaciens strain D747
  • Mineral oil 
  • Neem oil Clarified hydrophobic extract (Some formulations are OMRI-listed for organic use.)
  • Sulfur
  • Chlorothalonil 
  • Copper fungicides

Suggested pesticides are from the Pesticide Information Center Online (PICOL) Database. They are permitted for HOME use in Oregon. Read the label for application directions and effectiveness information.

ONLY professional pesticide applicators can use Restricted-Use Pesticides (RUP) that may be more effective. If you need further support, contact a licensed pesticide applicator.

Example label with active ingredient neem oil

Sample product label with Active Ingredient(s) highlighted

A red box on the example label highlights active ingredient Clarified hydrophobic extract of Neem oil. The label lists black spot. 

Fungicide Application Tips

  • Proper timing of fungicide sprays is important for them to be effective against rose black spot. 
  • Check for application timing on the label. It may be hard to control rose black spot once plants develop disease symptoms. 
  • Researchers recommend alternating products (by active ingredient). Local populations of rose black spot may develop resistance if only one type of fungicide is used repeatedly.
  • Using fungicides comes with real risks. ALWAYS read the entire label front to back. Review instructions even for brands you know.
 

If Using Fungicides, Protect Yourself & Minimize Risks

Chemical Method: Use with Caution
Gloved hands holding pesticide package to read label

Weston Miller, Oregon State University

Why Is It Important to Read Fungicide Product Labels?

  • They have detailed information on how to use the product correctly and legally.
  • They contain information on potential hazards of the product.
  • They provide instructions you should follow for poisonings and spills.
  • Following label instructions helps you to minimize the risks and maximize the benefits.

Key Fungicide Safety Tips

  • Read the entire label front to back.
  • Follow the instructions.
  • Review the instructions even for brands you know.
  • Only apply the product where the label says it can be applied.
  • Keep all fungicides in their original container.

The Label is the Law

ALWAYS read the label before using fungicide products. The label is a legal document that provides information on how to safely use the fungicide. This helps avoid harm to human health and the environment. Using a fungicide in off-label ways is illegal. It can result in legal enforcement actions.

READ THE LABEL & Follow Instructions
It has instructions to protect you and the environment.

  • Labels are different for every product and they often change over time.
  • Use a magnifying glass.
  • Pay attention to CAUTION, WARNING, and DANGER statements.
  • Pay attention to the PRECAUTIONARY STATEMENTS.
  • The law states you must read and follow fungicide instructions.

Protect Yourself
Eye, skin & lung irritants

  • Wear the correct personal protection equipment. The right gear often includes chemical-resistant gloves, safety glasses, a long-sleeve shirt, pants, socks, and shoes.
  • Mix fungicide products outdoors or in a well-ventilated area.
  • Wash hands after you mix or apply fungicides and before smoking or eating.
  • Wash clothes worn while mixing and applying fungicides separately from all other laundry.

Protect Children & Pets
Children and pets are at risk if they eat or touch the plant before fungicides dry.

  • Keep them away during and after applying fungicides (read label for how long).
  • Remove toys and pet dishes from yard before applying.
  • Don’t track fungicide products into home on shoes or clothes.

Storage & Disposal

  • Store out of the reach of children and pets.
  • Store in a cool and dry place.
  • Never pour down any drain.
  • If you mix too much, apply it rather than storing it.
  • Don’t put fungicide containers in the trash unless instructed by the label.
  • Take unused fungicides to a hazardous waste facility.

Call  1-800-CLEANUP (1-800-253-2687) to find out where to dispose of pesticides.

For the Portland metro region in Oregon, contact Metro’s Recycling Information. Call  503-234-3000, email   or visit Metro’s website  

More about:

Protect Pollinators

  • Apply early morning or evening when bees are less active.
  • Avoid spraying flowering plants, if possible.
  • Don’t spray on bees or insects.

About Using Pesticides on School Grounds in Oregon

If using pesticides on school grounds, there are special rules in Oregon. See School Integrated Pest Management  (Oregon Department of Agriculture).

NEED HELP?

The National Pesticide Information Center (NPIC)  can answer questions about pest control chemicals.
 1-800-858-7378 or npic@ace.orst.edu  

Consider using a licensed pest or weed control company. Learn How to Hire a Pest Control Company.

Your local Extension Specialist in Oregon  and other states  can suggest other methods.

 

PREVENT ROSE BLACK SPOT

Plant resistant rose varieties
  • Rust resistant rose varieties include ‘Carefree Spirit’, ‘Just Joey’, ‘Tournament of Roses’, ‘Europeana’ and ‘Showbiz’, climber ‘Dublin Bay’, and Rosa rugosa varieties.
  • For more varieties, See Rose Cultivar Resistance   (PNW Plant Disease Management Handbook).
Roses in container at store

rcmirani, iStock

Don’t bring diseased roses into your garden
  • Inspect new rose shrubs for rose diseases before buying. Avoid bringing a diseased rose plant onto your site.

Content provided by editor Weston Miller and writer Signe Danler. Pesticide safety information edited by Kaci Buhl.

 Peer reviewed by OSU Department of Horticulture.

Photo of Weston Miller

Weston Miller

Project Founder and Content Writer

Weston Miller served as Community and Urban Horticulture faculty for Oregon State University Extension Service for Clackamas, Multnomah, and Washington Counties. Weston is an author for content for this website. He developed funding partnerships with Portland area agencies to initiate and build out the Solve Pest Problems website focused on this goals:

Signe Danler

Signe Danler (Editor/Writer)

Signe supports the OSU Extension Master Gardener Program by producing educational content for online Master Gardener training courses, and teaching and managing the OSU-Extension online Home Horticulture courses. She also designs residential and commercial landscapes, specializing in regenerative gardening and landscaping practices.

Photo of Kaci Buhl

Kaci Buhl

At the state level, I lead the Pesticide Safety Education Program (PSEP). The program hosts live recertification events around the state, serving over 1,000 licensed pesticide applicators each year. We also produce web-based training modules and license-preparation study manuals. Special training for unlicensed pesticide applicators is also available through a grant from the USDA Specialty Crop Block Grant Program. The PSEP at OSU works closely with the Oregon Department of Agriculture's Pesticides Division.