Hello; Years ago a friend worked with both indoor and outdoor plants I recall her advising that when plants are effected by gnats to add 1-tsp. of bleach to one gallon of water, shake well and use that to water plants a couple of times - until infestation is died off.
I've used this method and it worked... but it's been many years and don't want to kill my plants either.
What are your thoughts...?
Thank you,
Theresa