Fungus Gnats - Houseplants Pests and how to Control them

houseplant Pest, Fungus gnat

Fungus Gnats

Fungus gnats are a major problem in houseplants. The small, black, flying adult is harmless. The problem is that it lays eggs in the soil which hatch into tiny, black-headed maggots which are harmful. These normally feed on organic matter in the soil but they can devour young roots. The gnats are troublesome in over-damp conditions. They multiply very fast and easily spread from one plant to another. Be on the look out for these black fly-like insects and take immediate control as they can infest your entire houseplants collection.

Control:
  • To prevent infestation, cover the soil surface with a layer of sand or ornamental stones and let the soil slightly dry out between waterings.
  • Where there is infestation, repot the plant in fresh soil, avoid overwatering the plant and institute the prevention measures.
  • Use yellow sticky traps to trap the adults and keep them from laying eggs.
  • Drench the infected soil with a solution of 4 parts water to 1 part rubbing alcohol. Repeat the treatment until the problem is cleared.
  • Drench the infected soil with a solution of 1 part hydrogen peroxide to 4 parts water and repeat as necessary.
  • Sprinkle Mosquito bits over the surface of the infected soil and water them in. Repeat until the problem is cleared.
  • Lightly spray all the plant surfaces with a Pyrethrin-based insecticidal spray and spray the infected soil to thoroughly moisten the surface. Allow the top 2 in. of soil to dry out before watering.
  • Drench the infected soil with an insecticidal solution as per the manufacturer's recommendations.

Was this insightful? Feel free to share on social media.


Related Articles



Related Articles


Houseplants Watering
How to Water Houseplants Correctly

Water is one of the major requirements for the proper growth of houseplants and without water a houseplant will die. Providing water for a houseplant is key and not just water. Read more »

Houseplant Temperature, Thermometer
Understanding Temperature for Houseplants

It is important to maintain the right temperature range for your houseplants. If the temperature is not right, growth may suffer. Read more »

Light for houseplants
Understanding Light for Houseplants

Light is a major component required by houseplants in making their own food for growth and energy in the process called photosynthesis. Read more »

Houseplants Hand Sprayer, Mister
How to Raise Humidity for Houseplants

Sometimes the indoor air can be very dry but very few houseplants can tolerate dry air. Employ these techniques. Read more »

Houseplant Fertilizer
How to Feed Houseplants

Feeding houseplants involves providing them with the nutrients they require for growth and good health. Plants need an adequate supply of nutrients. Read more »

Houseplant Pruning Scissors
How to Prune Houseplants

Pruning houseplants is meant to control growth of the houseplants, rejuvenate growth and keep the plant neat and attractive. Read more »