Sunday, July 3, 2016

Indoor Plants and Gnats! So Annoying...

How to Combat Those Little Flying Bugs - GNATS!

Although fungus gnats can be a problem with indoor plants at anytime of year, they can be a bigger problem during the warmer months as they are also outside in greater numbers and, no doubt, plotting an invasion of your home...  :)

Aglaonema Silver Bay Indoor Plant
Not a Fungus Gnat-Just One of My Plants
Here is a little information about fungus gnats:
  • Fungus gnats are small flies, about 1/8" long, black or dark colored. Adult females may lay up to a few hundred eggs in a 7-10 day period. And they will lay them in the moist topsoil of your indoor plants, if they get a chance.
  • Fungus gnat eggs hatch in about six days, producing small, white maggots.
  • Larvae will grow to about 1/4" in two weeks and then form pupae.
  • Then adults will emerge from plant media in a week or less. And the cycle begins again!
While adult fungus gnats do not damage your indoor plants, they can be very annoying. You may see numbers of them about your plants, if they are disturbed. They also seem to be attracted to lights, computer monitors, etc.

The larvae feed on organic material, including your houseplant's roots and can cause damage to your houseplant's health. This damage can allow disease to enter plant tissue.

Your plant may or may not show signs of decline. It is possible to have leaf loss, stunted growth and yellowing of foliage.

Properly watering your indoor potted plants (not keeping plant media constantly soggy) can help ease the problem to some extent. Using sub-irrigation containers for your plants is also a good way to keep these little pests from becoming a problem.

If you are having a problem with gnats in your indoor plants, one of the things you can do is remove the top inch or so of soil from your plants and replace with fresh, sterile soil. Gnats reproduce mainly in the topsoil of your plants so removing this and replacing with sterile potting soil should remove a large part of the problem.

It is best to use sterile soil for your indoor potted plants. Here are some ideas for sterilizing your own potting soil:
  • Place slightly moist potting mix in an oven proof tray. Cover with foil and bake for about 45 minutes in a 200 degree oven. Turn on the fan! Remove and allow to cool before using.
  • During the hot summer months, you can sterilize using the energy from the sun. Dampen soil and place in black plastic pot. Cover any drainage holes with plastic first. Set in the sun and cover with a sheet of clear plastic.This will adequately heat the soil and it should be ready to use in about a week. Saves electricity too!

One other helpful, non-chemical way to fight fungus gnats that are already present is to use sticky trap cards. These attract the fungus gnats, they get stuck and can not get away. Basically just fly paper in card form. I use these in my interior landscape accounts by placing them just inside the grow pot, usually stuck to the side. This catches the fungus gnats and keeps them from bothering anyone and from reproducing.

Hope this helps you with any problem you may have with these little, flying creatures.


Happy growing everyone!