Hortsense

• Avoid overhead watering. If overhead watering is necessary, water during the morning hours so leaves can dry quickly.
• Space plantings and prune to improve air circulation. Good air circulation limits disease development.
• Prune and destroy diseased leaves and canes. Do not compost diseased material.
• Rake and destroy all fallen leaves from under plants.
• Plant resistant varieties. Your county extension agent or WSU Master Gardeners can make recommendations.

Apply frequently in wet spring weather and occasionally in summer. Copper fungicides may cause some discoloration of foliage or blooms.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

• Bonide Copper Fungicide Spray or Dust RTU [Organic]
  Active ingredient: basic copper sulfate  |  EPA reg no: 4-58
• Bonide Fung-onil Multi-Purpose Fungicide Conc.
  Active ingredient: chlorothalonil  |  EPA reg no: 60063-9-4
• Bonide Infuse Systemic Disease Control Lawn & Landscape
  Active ingredient: thiophanate methyl  |  EPA reg no: 53883-183-4
• GardenTech Daconil Fungicide Conc
  Active ingredient: chlorothalonil  |  EPA reg no: 67572-82-71004
• Monterey Horticultural Oil [Organic]
  Active ingredient: mineral oil/pet distillate light  |  EPA reg no: 48813-1-54705
• Monterey Liqui-Cop Copper Fungicidal Garden Spray
  Active ingredient: copper-ammonia complex  |  EPA reg no: 54705-7
• Ortho Max Garden Disease Control Conc
  Active ingredient: chlorothalonil  |  EPA reg no: 239-2522
• Spectracide IMMUNOX Multi-Purpose Fungicide Spray Conc
  Active ingredient: myclobutanil  |  EPA reg no: 9688-123-8845
• This list may not include all products registered for this use.

Caption: Rose black spot on leaves Photo by: R.S. Byther
Caption: Rose black spot on leaves Photo by: R.S. Byther
Caption: Rose black spot stem infection Photo by: R.S. Byther