Fungus gnat invasion on marijuana!

A question from a fellow grower:

Hi there I need a solution to the fungus gnat invasion in having…please help its bad

Fungus gnats is usually a sign that you are over watering. Other detrimental things can happen from over watering as well. Exessive fungus gnats is a sign the soil is staying too wet too long and too often.

For most beginners it is safer to under water a little at first rather than over-water. Remember, in the wild, plants often will have to go a little with out a rainfall or such and a little wilting from being a little dry won’t really harm your plant. And it is much better than the alternative. For beginners you should wait until the pot and plant feel noticeably lighter and the first signs of leaf wilt from the soil being a little too dry before watering the soil to saturation. If your soil isn’t drying out in about a day or two and no more than a short few days(3-4) with a large fast growing plant, then your soil needs to be amended to drain better. Keep track of how long it takes for this lighter weight and slight wilting to occur and before you know it you will be able to tell when it is best to water just by glancing at your plant’s leaves, even before your average Joe is able to notice any leaf wilt. Also you may begin to see the leaf swell when too wet and this will give a good idea to back off on the watering before you end up with a fungus gnat outbreak and other water logged root problems. On average you should also notice timeline patterns for each strain, where they will use more or less amounts of water depending on different stages of the plant’s life cycle such as the amount of water required will change during different times of vegetative and flowering growth.

In the meantime, stop over watering and lots of yellow sticky traps and or fly trap ribbons. Also there is a specific color blue the fungus gnats seem to be attracted to, so smearing some “tanglefoot” (the sticky stuff that makes stick traps sticky) can be purchased in a container to smear on whatever you feel the need to have it on, some people make re-usable traps out of blue and yellow plastic square sheets.

1 Like