I spray it on the plants. I use Orthene granules mixed at a rate of 1 teaspoon per gallon of water. Orthene is a systemic organophosphate so use gloves and a mask when spraying it. You don't want to get much on your skin. Take a shower right after applying it to your plants. Orthene is also known for it's strong odor. The odor only lasts on the plants for a couple days but it really stinks. Store it where children can't get to it and where the odor won't bother you.