Helps: roses, peppers, asparagus
Helped by: basil, oregano, parsley, carrots, marigold, Alliums, celery, Geraniums, Petunias, Nasturtium, Borage, any type of onion or chives
Attracts: Tomato Hornworm
Repels: asparagus beetle
Avoid: Black walnut, corn, fennel, peas, dill, potatoes, beetroot, brassicas (kohlrabi, cabbage, etc), rosemary
Comments: Black walnuts inhibit tomato growth, in fact they are allelopathic to all other nightshade plants (chili pepper, potato, tobacco, petunia) as well, because it produces a chemical called juglone. Dill attracts tomato horn worm.