Marigolds (Tagetes sp.) belong to the family Compositae. These plants are known to control a wide range of nematodes including the Meloidogyne (root-knot nematodes) and Pratylenchus. Marigolds can be used as a cover crop or in a crop rotation. When grown as a mono-culture in high density their nematode suppressing effect is highest.

Extracts of marigold are known to be effective repellents against aphids and other insects.

Tagetes with bee
Extracts of Marigold (Tagetes) can be used as repellents