Sick Basil Plant – Leaf Tips of New Growth Turning Black
This problem was a very sudden onset. New growth is turning black at leaf tips. Other plants nearby are not being affected. Older growth has begun yellowing and some have brown spots. Sprayed it with neem oil but that is not stopping it. There are blooms on it and I haven't cut them off to slow the growth some.
I would trim back to green leaves. If this continues on the affected plant, it should be removed.