Do Marigold Flowers Get Rid of Cockroaches?

Natural Pesticide

• Marigolds of the Tagetes erecta and Tagetes minuta family, including American marigold, African marigold, Aztec or Mexican marigold, have been found to contain pyrethrum, an insect neurotoxin, previously only found in Chrysanthemum cinerariaefolium and C. coccineum. Pyrethrum disrupts the insect's nervous system causing paralysis and prevents the insect's eggs from hatching. It is considered non-toxic to mammals, but care should be taken if used around babies and small pets. Other varieties of marigolds such as pot marigolds (Tagetes calendula) do not contain pyrethrum, but do contain terpenoids, which also act as insect repellents. Marigolds have been killing and repelling a wide variety of insects in gardens and homes for centuries.

Marigold Tea

• Pour boiling water over marigold flowers and leaves and let it steep for several hours. Adding a bit of dish detergent to the mix helps it cling where it is sprayed. Strain the mixture and pour into a spray bottle. Spray around areas where roaches enter the house. Do not wipe up for several days. Keep in mind that marigold flowers are also used in dyes and may tint light-colored fabrics or painted walls. Label the bottle and keep the tea in the refrigerator.

Marigold Powder

• Pick marigold flowers and allow them to dry. Pulverize them with a mortar and pestle or simply crumble them in your hands. Sprinkle the powder in the bugs' favorite places such as the corners of cabinets and drawers, along baseboards and under appliances. Cockroaches will avoid these areas. Regular treatment with the powder will discourage the roaches from establishing a permanent habitat.

Marigold Plants

• Planting marigolds around the perimeter of the house can help prevent roaches from entering. It is not a strong barrier, but it can be a part of an overall program of cockroach preventative. The plants are annuals so they generally have to be planted every year, but they will often self-seed and bloom again in the second year. Setting potted marigolds around a patio, deck or porch is an additional way to bring more pyrethrum and terpenoids to the fight against cockroaches.