Neem oil has a dual purpose in the vegetable garden as both a pesticide and a fungicide. It works on arthropod pests that often eat your vegetables, including tomato hornworms, corn earworm, aphids and whiteflies. In addition, neem oil also controls common fungi that grow on vegetable plants, including: Mildews.

Neem Oil acts as an systemic pesticide, meaning the plant will absorb the Azadirachtin compound and distribute it throughout its vascular system. Once distributed, any part of a treated plant a pest ingests will also contain the Azadirachtin.