What do organic farmers do
to control pests if they
can't use chemicals?

Prevention methods begin with the soil. A healthy soil makes the plants that grow in it more resilient to disease. When pest populations are high, time honored prevention methods like the use of insect predators, traps and barriers are used. Only under the most severe conditions will the certifier grant the use of botanical pesticides. By definition, a botanical pesticide is made of natural products (that are plant-based) and are broken down by the elements-air and sun.