You can treat your plant with Neem oil by drenching the soil at the very first sign of a fungus gnat. … Neem oil won’t kill all of the pests on contact, so it might take a few days, weeks or even months for all of the bugs to disappear from the plant.

Does Neem oil kill gnats on contact?

Neem oil is an all-natural, non-toxic insecticide that kills many pests on contact, including fungus gnats.

How long does it take for neem oil to kill gnats?

Neem oil won’t kill all of the pests on contact, so it might take a few days, weeks or even months for all of the bugs to disappear from the plant. If you see a lot of little gnats, you probably have too many in your soil for the Neem oil to wipe them out. At this point, the best plan is to repot your plant.