Calendula officinalis, the pot marigold, ruddles, common marigold or Scotch marigold. It is probably native to southern Europe, though its long history of cultivation makes its precise origin unknown, and it may possibly be of garden origin. It is also widely naturalised further north in Europe (as far as southern England) and elsewhere in warm temperate regions of the world.
The Latin specific epithet officinalis refers to the plant’s medical and herbal uses.
Calendula officinalis is a short-lived aromatic herbaceous perennial, growing to 80 cm (31 in) tall, with sparsely branched lax or erect stems. The leaves are oblong-lanceolate, 5–17 cm (2–7 in) long, hairy on both sides, and with margins entire or occasionally waved or weakly toothed. The inflorescences are yellow, comprising a thick capitulum or flowerhead 4–7 cm diameter surrounded by two rows of hairy bracts; in the wild plant they have a single ring of ray florets surrounding the central disc florets. The disc florets are tubular and hermaphrodite, and generally of a more intense orange-yellow colour than the female, tridentate, peripheral ray florets. The flowers may appear all year long where conditions are suitable. The fruit is a thorny curved achene.
Diseases and Problems
Calendulas are used as food plants by the larvae of some Lepidoptera species including Cabbage moth, Gothic moth, Large yellow underwing, and Setaceous Hebrew character.
Calendula officinalis is widely cultivated and can be grown easily in sunny locations in most kinds of soils. Although perennial, it is commonly treated as an annual, particularly in colder regions where its winter survival is poor, and in hot summer locations where it also does not survive.
Calendulas are considered by many gardening experts as among the easiest and most versatile flowers to grow in a garden, especially because they tolerate most soils. In temperate climates, seeds are sown in spring for blooms that last throughout the summer and well into the fall. In areas of limited winter freezing, seeds are sown in autumn for winter color. Plants will wither in subtropical summer. Seeds will germinate freely in sunny or half-sunny locations, but plants do best if planted in sunny locations with rich, well-drained soil. Pot marigolds typically bloom quickly from seed (in under two months) in bright yellows, golds, and oranges.
It is recommended to deadhead (remove dying flower heads) the plants regularly to maintain even blossom production.
Pot marigold florets are edible. They are often used to add color to salads or added to dishes as a garnish and in lieu of saffron. The leaves are edible but are often not palatable. They have a history of use as a potherb and in salads.
Flowers were used in ancient Greek, Roman, Middle Eastern, and Indian cultures as a medicinal herb, as well as a dye for fabrics, foods, and cosmetics.Many of these uses persist today. They are also used to make oil that protects the skin.
Marigold leaves can also be made into a poultice that helps scratches and shallow cuts to heal faster, and can help prevent infection.
Plant pharmacological studies have suggested that Calendula extracts may have anti-viral, anti-genotoxic, and anti-inflammatory properties in vitro. In an in vitro assay, the methanol extract of C. officinalis exhibited antibacterial activity and both the methanol and the ethanol extracts showed antifungal activities.
Along with horsetails (Equisetum arvense), pot marigold is one of the few plants which is considered astringent despite not being high in tannins.
Calendula flower is used to prevent muscle spasms, start menstrual periods, and reduce fever. It is also used for treating sore throat and mouth, menstrual cramps, cancer, and stomach and duodenal ulcers. Calendula has also been used for measles, smallpox, and jaundice.
Calendula is applied to the skin to reduce pain and swelling (inflammation) and to treat poorly healing wounds and leg ulcers. It is also applied to the skin (used topically) for nosebleeds, varicose veins, hemorrhoids, inflammation of the rectum (proctitis), ear infection, gum disease, peeling lips (exfoliative cheilitis), diaper rash, vaginal yeast infection, and inflammation of the lining of the eyelid (conjunctivitis). Essential oil of calendula has been used as an insect repellant.
It is thought that the chemicals in calendula help new tissue grow in wounds and decrease swelling in the mouth and throat.