How can I get rid of gnats on my petunias?

Answer by  BrendaG (6111)

A homemade salt spray will help fight gnats and other nuisances. Spray plants once a week with spray made from two tablespoons of salt added to one gallon of water. You can also buy insecticides for this purpose.

Answer by  ToyotaDude (44)

Fertilome is a great gnat product that seems to help the most. The only catch is that you have to keep spraying daily repedetly. This is because you are only killing off adult gnats while eggs are in the soil. Limit watering so that the eggs in the soil die off. Eventually you'll kill them all off.

Answer by  worker7162 (166)

gnats can be attack plants in cool months to avoid this you can use organic spray and keep the soil temperature (60 degree) and petunias need full sun all day..