Black Spot


Primarily affects roses. At first, lower leaves of susceptible plants become covered with brownish-black spots; eventually the leaves yellow and drop off. A severe infestation can completely defoliate a plant over a period of weeks. Disease spores are spread by rain and irrigation. Black spot spreads quickly in wet or humid, warm weather.


Avoid wetting foliage. Prune plant to allow good air circulation among branches. At the first sign of disease, remove infected leaves and begin spraying a sulfur-based fungicide or a soil inoculant every 5-7 days for control. Clean up any dead leaves from the base of plants (don't compost dead or diseased leaves), especially in fall. We recommend Plant Guardian™ Biofungicide Liquid Concentrate or Sulfur Guard™ Fungicide.

« Back to Garden Diseases

Related products

  • Plant Guardian Biofungicide

    Controls bacterial spot, powdery mildew, rust, gray mold, leaf blight, scab and more. Plant Guardian Bio-fungicide effectively controls or prevents a wide range of important fungal and bacterial plant diseases and may be used on...

    Read More

Sign-Up and Save

You’ll enjoy…

  • • Exclusive offers and specials
  • • First access to new products
  • • $25 off your first order of $50+

Gardens Alive!® respects your privacy. Unsubscribe anytime.

Close Pop Up