Fungal infections are difficult to treat since the usual fungicides are more toxic than the actual disease itself and never fully destroy all the spores occurring naturally. The sprays can also be messy to apply. The best treatment is sanitation to prevent re-infection in the upcoming season.
- Start by raking up all the fallen leaves, debris and branches.
- Don’t use them for mulch since the spores can overwinter and become airborne in the spring spreading the infection.
- Tekavcic also recommends fertilizing to boost the tree’s immune system combined with a light pruning to remove interior branches and improve air flow. “Just be sure to do the pruning and fertilizing after leaf drop when the tree has become dormant,” says Tekavcic.
- “A mild sulphur-based spray can be used if the infection is serious, but sprays are not that effective and shouldn’t be used on the fungal infections that are not fatal,” she recommends.