Q: Can insects be controlled by Companion Planting?

A: Yes. Included is a partial listing of specific controls:

marigolds for companion plantingPlant basil against flies and mosquitoes;
borage against tomato worms;
garlic against Japanese beetles, aphis, weevils, fruit tree borers, and spider mites;
horseradish against potato bugs;
lavender against clothes moths;

marigolds against Mexican bean beetles, nematodes and many other insects;
mint against white cabbage moths (use dried against clothes moths);
nasturtium against aphids, squash bugs, striped pumpkin beetles, wooly aphids and white flies;
pennyroyal against ants, mosquito, plant lice;
petunias against beetles;

rose geraniums oil or crushed leaves as insect repellants;
rosemary against cabbage moths, bean beetles, carrot flies; rue against Japanese beetles;

sage against cabbage moths, carrot flies and ticks;
summer savory against bean beetles;
tansy against flying insects, Japanese beetles, striped cucumber beetles, squash bugs and ants;
thyme against cabbage worms.