Can be used on all indoor house plants, tropical plants and any time you add more potting soil to your plants * Fungus gnat control nematodes are microscopic worms which seek out larval stages of various fly and other dipteral insects which develop in the soil * Easy to apply with a watering can or hose-end sprayer for outdoor uses * Ideal preventative treatment for tropical plants which are brought indoors after the outdoor gardening season is over