Q.problem with basil wilting
All of a sudden my basil (sweet basil) plants wilt and shrivel, starting from the top. No bugs anywhere, at least not on leaves. Soil is fresh from large bags. Problem is only in one container. I grow the basil on the roof in NYC and gets good sun, water. Had just put in agri-fos, a safe fungicide and never any trouble before. Other pots have same mulch, soil, water, agr-fos, etc but are healthy.
Normally, fungus would take a while to affect plants. Stem turns brown and plant slowly dies. This is first time the plant quickly wilted without any signs. Wilting starts at upper leaves and droop over, stem curves down. Bottom leaves healthy but soon wilt. Only one section of one pot has trouble so far. All other plants are fine. I gave all the plants another agri-fos spray. I also sprayed when there was no problem, which should have prevented any fungus. So this is a mystery. When I pulled a wilting plant up, the main root was nice and long. Didn’t see any bugs.
Fusarium Wilt is a common issue with Basil plants.
These articles will help you pinpoint the cause.