How to Control Black Spot Fungus on Roses

Black spots and yellow leaves on rose bush
The signs of black spot fungus on roses are hard to miss.

Black spot (blackspot) is one of the most common diseases of rose bushes; and, if left unchecked, it can cause quite a bit of damage to your rose garden.

Caused by the fungus Diplocarpon rosae, black spot begins just as its name suggests, with black spots showing up on the surface of the leaves.

As the spots grow larger, they become ringed with yellow, eventually causing the whole leaf to turn yellow and fall off. The stems may also have black or purplish spots. If not treated, black spot will leave your rose garden not only naked, but significantly weakened and unprepared for the next winter.

Like most fungal diseases, black spot thrives in wet, humid weather, usually when temperatures are in the mid-70s Fahrenheit. The spots produce spores which spread to other leaves and plants. The spores can survive the winter in fallen leaves and infected canes.

Rose leaves with yellowing and black spots
Leaves on roses with black spot eventually turn yellow and fall off.

While black spot may seem relentless in your rose garden, it’s actually easy to manage with the right treatment and prevention strategies. Here’s how to control black spot in your garden.

How to Treat Black Spot

If you’ve noticed telltale black spots on your roses, you should:

Remove Infection

Prune away the infected leaves and infected stems. Also, rake up all the fallen leaves under the plant. Throw the infected debris away, rather than putting it on your compost pile.

Spray Roses

Spraying rose bush with neem oil
Neem oil fungicide for black spot.
Once the infected leaves and stems have been removed, treat your rose with a fungicide. Spray the entire plant, making sure to get the tops and bottoms of the leaves as well as the stems. You can use a chemical fungicide or any number of organic options such as:

  • Copper
  • Lime Sulfur
  • Neem Oil
  • Potassium or Ammonium Bicarbonate
  • Sulfur

How to Prevent Black Spot

With these gardening habits in place, you can keep black spot at bay:

  • Water in the Morning: This allows the moisture to evaporate from the leaves.
  • Avoid Watering Foliage: Especially if the weather is warm and humid, avoid getting the foliage wet when watering.
  • Choose Resistant Roses: Some varieties of rose are resistant to black spot.
  • Allow Air Circulation: Choose a planting site with plenty of air circulation, and be sure to space your roses 3-4 feet apart. Prune dense bushes to let air circulate between the branches.
  • Dead rose leaves on ground under bush
    Discard fallen leaves under rose bushes.
  • Choose Sunny Location: Roses prefer full sun anyway, and choosing a sunny location for your rose garden will help burn off moisture.
  • Keep Garden Clean: Regularly rake and clean up around your roses, and throw away any fallen leaves. This is especially important in fall and winter, to remove spores that might be awaiting the spring warm-up to become active. After the cold-weather cleanup, apply fresh mulch to keep any remaining spores away from your roses.
  • Stay Alert: Inspect your roses regularly, and immediately remove and throw away any spotted leaves, both on the plant and on the ground. If the problem isn’t severe, this may be all the treatment you need.
  • Preventive Treatment: If black spot is a perennial problem in your yard, begin a preventive treatment with an organic, nontoxic, fungicidal spray (such as those on the list above), right before your roses sprout in spring. Continue treatment every couple of weeks to keep the fungus under control.

Further Information

55 COMMENTS

  1. Love your show! Would you please advise on how to get rid of the pesky Japanese Beetle. I’d like my “rose restaurant” to be closed to them in 2013. Thank you.

  2. I am new at planting anything i have some minature roses and i noticed the speckled leaves on the bushes ,i have been picking the infected leaves off the plant not knowing that i was doing the right thing alas i did not dispose of the infected leaves i just dropped them on the ground thanks to this article i know now what to do thank you so very much.

  3. I purchased 2 rose trees(small miniature roses)(one red rose and the other white) in pots in April. They were beautiful, full of flowers and buds. The next set of blossoms came in tiny and never opened much. They are dry looking with black in the center… I have tried pruning them, am careful not to over water, etc. I think they have a fungus.. What do you suggest?

  4. should I use dormant oil or lime-sulfurs spray on and around my rosebushes before I mulch them for winter? I have had had some problems with black spot disease.

  5. Dear Sir,
    Thank you for your valuable informetion on blackspot of roses. Please give some hints on sticker used with fungicide.

  6. I would like a recipe for black spot on roses that is not a chemical, I think it has soda and something else that would be found in the kitchen. Also will skim milk really do the job?
    Thank you so much.

  7. I have heard that it is Dawn and baking soda and water, like 2 squirts of dawn, 2T baking soda, and then fill with water. Spray bottom and top of leaf. Repeat every week and after rain.

  8. Thank you for the information, I try to keep on top of my roses. I sometimes over water if I forget. Anyway this was a big help, I went right out and cut the bad leaves and sprayed. Again, thank you

  9. I live in Portland, Oregon. It rains all fall, winter and spring. Sometimes off and on in summer. Last year, black leaf spread to all of my miniature roses. I removed infected leaves and stems. One bush wouldn’t clear and kept re-infecting the others. I’ve separated it from the others. I can re-pot the ones that cleared up last year, but what else can I do to keep them clear and what can I do for the other bush? It is February, rainy, and the bush is starting to grow again, but already has black leaf this year.

  10. Nearly all my roses have black spot. They are still flowering since October. Will it hurt to prune now as they growing pretty messy?

  11. Heard I could spray 1 cup milk mixed with 2 cups water on my roses to get rid of black spots. Will this work?

  12. What do you do with the diseased leaves when you remove them? You can’t put them in the rubbish bin, can’t burn them, so what do you do, please.

  13. I have a beautiful red climbing rose.this is the second year and the flowers are in abundance.alas the leaves had. Blackspot I treated the plant with required spray that was called BUG.I is for numerous conditions,blackspot one of them. The leaves turned yellowish, and worse than before. (I forgot to add, the flowers are all droopy, no sign of greenfly) I tried spraying again, and the whole plant has near but died, except one stem seem OK except droopy flowers.
    I have cut all the affected stems right down and discarded. So apart from the long stem not too infected, I have lost this plants growing year.
    What have I done wrong,or has my rose another disease, being that the f!owners are droopy, which you don’t mention a condition for black spot ( just leaves).
    Any help would be appreciated.

  14. I can see my rose plants start flowering but buds don’t grow to become blooms . They shrivel and become black. I wonder why. I in south India, Asia. The plant enjoys full sun light.

  15. I have a Rio Samba Hybrid Tea Rose. I am having a major problem w/ Black Spot. I have done everything I now to do to stop it. I live in North Texas, zone 7b to 8a. Used every treatment, except a natural remedy. It is late October & has stopped blooming & all the leaves are covered w/ black spot, I have removed the leaves as soon as I saw the black spot appearing & disposed of them properly. It has only a few leaves left, should I prune the stem? And if so how much should I prune it back? I lost this very same type of Rio Samba to Black Spot 2 yrs. ago & am trying my best to save this one. I would appreciate any help I can get, I am afraid it will infect my other climbing rose, which only has a little black spot & I remove the leaves on it immediately. I’m afraid if I remove the leaves left on the Rio Samba it will die, but if I don’t I know it will die. Help me please, I don’t want to lose this one.

  16. I’m from Melbourne, Australia. I found u’r info on black spot helpful, but am looking for a safe treatment for it, I have grandkids & staffordshire bull terriers, and won’t use anything unsafe. I even kill weeds with boiling water rather than risk it. is there an organic nonchemical mixture that works?
    thnx

  17. Its been non stop raining and now its getting the spots. I cant help the rain. Any suggestions plz. If I move them to my back porch then thet wont get any sun.
    Thank You

  18. Sandra bennett, use Cleary 3336F. mix .5-1.5 teaspoons to each gallon of water. Spray every two weeks.-Robert Saville

  19. I have an Anniversary Rose bush, lovely red with creamy centre. I have it in a large pot in full sun against a south facing wall. This us its first season with us. It has had loads flowers and was glorious, lots dark glossy leaves 13 buds on at one point.
    We have had about a month of almost constant rain and now black spot has arrived. I took off affected leaves and within a week the rest of them are affected. If I take them all off there will not be anything left H E L P P L E A S E !!!

  20. Remove all discoloured leaves, flick the plant with a soft brush to remove any leaves that are ready to drop & remove the fallen leaves from beneath the plant. Make up a spray as follows, In a gallon of water mix 2 teaspoons of Bicarbonate of Soda, 2 teaspoons of washing up liquid & 2 teaspoons of vegetable oil, mix well and spray all over the plant under & over the leaves until the spray drips off the leaves. Repeat every 2 weeks.

  21. I am going to go with either a fungicide spray or milk and water, I recently tried the baking soda, vinegar, vegetable oil and hand soap and I’m guessing it changed the ph so much that it literally turned my roses and leaves solid black. I have been pruning, raking mulch and pulling leaves for days now to no avail. I used the mixture to the tee which I pulled from another website, I’m assuming the vinegar is what caused the total damage completely changing the PH, maybe leaving it out it quite possibly have worked! Thank you for your tips.

  22. I moved to a new property where roses were not pruned in last 2 years and disease made them ugly. So, I am pruning in September, will treat the disease, clean out all leaves from the bed and pray for the best. Some watering will help too. Hope it saves them for next year.

  23. I have an inherited trail rose . It spread about 10 ft in each direction. I treated it last yr as suggested but it came back as bad this year. I really don’t want to cut it back as it’s so beautiful when it blooms and covers the entire fence. It’s in a sunny position with little shade. Any suggestions?

  24. I have climbing rose But it will only have just two roses every year n it as black spots on the leaves and then eventually fall off
    Please could you advise me on this.

  25. Very informative and enlightening. I was spraying but mot the undersides of the leaves and I was not raking up the fallen leaves.I will start right away.

    Thank you

  26. ok so how will I water my roses I have other plants next to them that need water and what is the right time of the day to water the roses I did buy same fungus spray so how often should I water my roses
    thank you Del

    • Hi, Tony,

      Gardening questions can be tricky since the rules can change based on the region. We would suggest contacting your local Master Gardeners association.
      Master gardeners train on a range of topics so they can provide advice, at no charge, for people in their area.

      Thanks for your question, and good luck!

  27. Black spots on my standard roses i used the comercial fungice for blac spots it does not work could you please advice in this problem thank yyou john

    • Hi, John,

      Gardening questions can be tricky since the rules can change based on the region. We would suggest contacting your local Master Gardeners association.
      Master gardeners train on a range of topics so they can provide advice, at no charge, for people in their area.

      Thanks for your question, and good luck!

  28. We have a standard Rose one year old it is early summer in New Zealand and we have had a lot of rain,do I strip the leaves now and stems ie prune it or put fungicide on,Thanks for your help.

  29. Please give me advice on how to get rid of rust spots on my rose. Prefer home remedy if possible. If not commercial spray will be used
    Thanks

  30. I have small roses that are potted on my patio that is infected. Can it infect my other potted hydrangeas that are near as well?

    • Hi, Carol,
      Some things you can only determine in person (and this is one of ’em)! We suggest contacting your local Master Gardeners association for a quick visit. Master gardeners train on a range of topics so they can provide advice, at no charge, for people in their area.
      Thanks for your question, and good luck!

  31. I have followed these steps and just when I think it’s gone it comes back! I water at the base, cut back everything and spray weekly with a treatment that says it’s for black spot. Any other ideas? We pick up the leaves on the ground and I place then in a bucket to move far away so they aren’t left by the roses.

    • Hi, Amy,
      Sorry to hear this fungus keeps coming back.
      We’re opening this question to the TodaysHomeowner.com community.
      Any ideas, y’all?

  32. Hi,

    On black spot on roses: I have dealt with black spot for 3 years here in washington state, to which I rarely had to contend with in Boise. Dryer climate obviously. Some of my rose here are disease resistant, to where others are more prone to rust, black spot, white mildew. You have to stay a step ahead of these things. Spring treated is best to get ahead of the issues. Then by midsummer, it’s baaaaack!, but easier to maintain at this point. I use and swear by BioAdvance 3 in 1 spray. It treats many different problems all at one time…insects included and it waterproofs your shrubs. You can use this on anything except fruits and vegetables. I suggest that if you do not want to or have time to baby your roses on a regular basis/fight diseases then look for roses that are more disease tolerant. They have many varieties that are beautiful and fragrant without the fuss and hassle of trying to keep them alive.

  33. Having so much problem with black spot. As soon as I see a hint of the disease, I spray but doesn’t seem to stop the spread. Just wondering if I should use Mancozeb which should kill off the black spore spores and prevent the disease spreading up the rose.
    Simply don’t know much about this fungicide especially on young roses.
    Could you help?

    • Hi, Marian,
      We haven’t used Mancozeb and could not vouch for its effectiveness.
      That said, we do recommend seeking advice tailored to your zone.
      You didn’t mention the location, so we suggest contacting your local Master Gardeners association.
      Master gardeners train on a range of topics so they can provide advice, at no charge, for people in their area.
      They’re awesome, and can steer you in the right direction.
      Thanks for your question, and good luck!

  34. I enjoy your program for the roses growing and hope to get good way remove the black spots on the leaves

    Brisbane Australia

  35. Thank you for the information on black spot treatment. I have a major problem with black sport on a climbing rose. The leaves have fallen or I have pruned all the infected leaves up to 5 feet from the bottom of the rose. So far the ends of the plant are still healthy and growing. Will the lower part of the canes produce new leaves eventually?

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