Black spot disease spreads from drips and splashes in moist conditions. Your plants are especially prone to it if the leaves stay wet for a long time. In the case of indoor plants, you can take these steps to prevent black spots:
- Water from the bottom of the plant to keep the leaves dry.
- Water early in the day to let the leaves dry.
- Ensure good ventilation of foliage.
- Do not mist the leaves unless it’s a requirement for your plant.
In the case of outdoor plants, here are some additional measures:
- Keep the base of the tree clean of fallen infected leaves by raking.
- Prune the lower canopy that rarely dries out and leave the upper one intact.
- Plant new greenies apart from each other so they don’t touch when mature.