Nematode Control Marigold was developed for the control of nematodes in crop fields and is a good alternative to chemical nematicides and fumigants. Nematode infestation can lead to millions of dollars in damage every year. Typical crops that can benefit from Nematode Control Marigold include potato, tomato, tobacco, curcurbits, soybean and squash. The Marigold cover crop should be grown prior to planting the cash crop and tilled into the soil as a green manure. In areas with short growing seasons, the Marigold should be grown as a cover crop the previous season.