For effective organic gardening, you need to visually inspect all the plant leaves in the morning, evening and especially after a rainfall to remove any unwanted visitors.
also planting certain plants together will repell an unwanted visitor. such as planting basil between tomato plants will repel tomato hornworms.
I too am an organic gardener and living in humid southwest florida means we have lots of pests. I work very hard to not use chemicals as I have many birds, butterflies and bees that visit my yard. I check my plants daily for pests or fungus and at the first sign I treat with a green product. Preventative measures such as crop rotation and interplanting herbs between vegetables or roses also works well. Herbs are rarely attacked by pests as their natural chemical structure makes them unpalatable to chewing insects. As you harvest your tomatoes you can also pick basil leaves. Later you can layer them with slices of fresh mozzarella, drizzle with olive oil and serve.
