Black spot is a common fungal disease causing dark brown to black leaf spots on the upper surfaces.
Identify the problem
Black spot is caused by fungus. Dark-brown to black leaf spots develop on the upper leaves, which eventually become yellow and drop.
Black spot can be distinguished from other leaf spot diseases by its fringed edges and dark black colour. Raised, reddish-purple spots may also appear on the plant. Warm, humid conditions favour its germination and growth.
- Good garden hygiene is important for treating black spot. Remove garden litter, ensure plants have plenty of sunlight and good circulation. During the growing season, overhead watering should be avoided.
- To control blackspot spray with PLANThealth Fungus Control or PLANThealth Spectrum. PLANThealth Fungus Control and PLANThealth Spectrum are a systemic fungicides. Spectrum combines an insecticide.
- Prevention is always better than cure. Measures to improve black spot disease control include ensuring appropriate planting sites, the use of resistant cultivars, and regular pruning (for more information read Protect Your Plants from Disease). Early spraying with PLANThealth Liquid Copper and/or Organic Super Sulphur will help prevent disease.
Did You Know
Black spot disease is caused by variety of fungi:
- Black spot in apples also known as apple scab - Venturia inaequalis
- Citrus black spot - Guignardia citricarpa
- Rose black spot - Diplocarpon rosae