When tulsi leaves turn black, it can be due to several factors, usually related to environmental stress, pests, diseases, or soil conditions. Starting with environmental stress, it’s crucial to ensure that your tulsi plant receives the right amount of light and water. While sunlight is beneficial, too much direct sun or erratic watering can lead to stress resulting in black leaves. Consider shifting the plant to a spot with filtered sunlight and consistent watering, ensuring the soil remains moist but not waterlogged.
Disease can also play a role. Fungal infections such as Cercospora leaf spot or bacterial infections might lead to blackening. Check the undersides of the leaves for any visible mold or web-like formations, which can indicate a pest or fungal issue. If so, an application of neem oil or a mild baking soda solution (1 teaspoon baking soda in 1 liter water) can be sprayed on affected leaves to control the situation. Do this in the morning to allow it to dry with the daylight hours.
Soil quality and drainage are also essential. Poorly drained soil retains too much moisture, suffocating roots and encouraging fungal growth. Make sure your pot has effective drainage holes and consider adding some sand or perlite to your soil mix to improve its aeration and drainage.
You mentioned trimming the leaves, which can help but remember to use clean, sterilized tools to prevent spreading any pathogens. Monitor for improvement; if the issues persist, consider repotting with fresh soil, inspecting roots for rot, and removing any affected parts.
While tulsi is hardy, a severe disease or root issues can require professional guidance. If the plant keeps declining, consulting with a local horticulturist or plant expert may provide more targeted advice. This way, you might save your purifying plant before things worsen.
