I read that plants that have umbril shapes like parsley and Queen Anne's Lace deter hornworms as the tiny wasps that destroy the hornworm pupae like these plants. The summer that I planted parsley under the peach tree instead of the garden, I was inundated with hornworms even though the tree is only a few feet from the garden. When I resumed planting parsley in the garden, the hornworms disappeared.

I wonder why. I didn't know what they were and I was picking in the garden and grabbed one. YUK! It was so soft and mushy. Now I know. My tomato plant was almost all eaten. Thanks Jan

Planting dill and marigolds has not kept me from getting them. It is possible that without these plants I would have far more than I do! I still pick off at least 10 to 20 each year. I grow around 15 to 20 tomatoes a year. I inspect them every morning.

I plan several basil plant around tomatoes to deter sphinx moths from laying eggs. It seems to work.

I plant lots of basil, too. Same deal as dill and marigolds.