Two Great Options
When discussing marigolds, it’s important to differentiate the two genera, both of the aster family, that share the same common name. Pot marigolds (Calendula officinalis) are native to southern Europe and have been known and used in food and medicine since ancient times. African marigolds, French marigolds, Mexican marigolds and several others (Tagetes species) originated in the New World from far southwestern North America to northern South America and were carried around the world by post-Columbian Portuguese and Spanish vessels. These marigolds quickly made their way to India, Spain, France and North Africa where they were further domesticated and in some cases naturalized. Apparently Tagetes bore enough resemblance to Calendula to warrant the same common name as it’s Old World cousin.
Pot marigold is probably given that distinction because of its culinary usefulness. Ancient Arabs, Greeks and Romans were all familiar with calendula and had a variety of culinary, medicinal, cosmetic and other uses for the flower. A few petals added to rice will add a yellow tint, and the same is true in cheese making. An infusion of flower petals steeped in water will heal dry, cracked skin, spots or enlarged pores.
Calendula is considered by herbalists to be an excellent antiseptic for eczema, ulcers, rashes, fungal infections, varicose veins, minor wounds, burns and sunburns. Many over-the-counter cosemetics have calendula in them. Even our healing lotion bar uses an extract of calendula.
Two species of Tagetes are of general herbal importance: Tagetes lucida (Mexican tarragon) and Tagetes patula (French marigold). French marigold made it to Europe in the 1570’s and is widely grown, with lots of varieties available. Mexican tarragon was more than two hundred years later to arrive on the European horticultural scene, and has not become as popular.
Mexican tarragon, along with the closely related T. anisatum (anise marigold) and T. filifolia (Irish lace marigold), have an anise-like flavor and may be used where true tarragon is difficult to grow. French marigold has become a popular flavoring in parts of Africa and central Asia. Both species are diuretic and helpful in relieving indigestion.
T. erecta (Aztec or African marigold) features pungent leaves and yellow flowers that may be used similarly to saffron/calendula. T. lemmonii (Copper Canyon daisy) and T. tenuifolia (lemon or signet marigold) have lemon scented flowers and foliage.
Helping Your Garden
Both Calendula and Tagetes offer benefits for your garden. Calendula tea has been used as a natural insecticide, with studies showing reduced cabbage moth and cutworm damage. The pot marigold is also useful in cleaning and restoring polluted soil, building populations of beneficial soil fungi and reducing populations of root knot nematode. Tagetes are effective against root knot nematodes, when used as a cover crop for three or four months before or between production crops. As a companion, they help repel whitefly and rabbits.
Marigolds prefer sunny, well drained average garden soil. Both Calendula and Tagetes grow in hot and cool weather until hard frost arrives, providing a long bloom season. The plants will continue to bloom profusely if you deadhead the spent blooms. Limit fertilizers on marigolds; fertilizers stimulates lush foliage at the expense of flowers.