Sweet Basil Leaves Turning Black

Question

Why are my sweet basil leaves turning black on the undersides? The new leaves are beautiful but as they grower larger, the leaf develops black underside, similar to mildew, but not on the tops. How can I fix this problem? What am I doing wrong, as new to growing in Florida.

Answer 1

Sounds like a fungus, possible from too much moisture or even pests. Remove infected leaves and treat the plant with neem oil. Here is more information: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm, https://www.gardeningknowhow.com/edible/herbs/basil/basil-diseases.htm, https://www.gardeningknowhow.com/edible/herbs/basil/how-to-grow-basil-plants.htm