Calendula Uses, Benefits, Side Effects, and More

Calendula (Calendula officinalis) is a short-lived perennial in warmer climates, but in cooler climate zones it is usually grown as an annual flower in garden beds and containers. Although commonly known as pot marigold, calendula differs from the common marigold (Tagetes spp.). It is, however, part of the Asteraceae family along with daisies and chrysanthemums, and has a daisy-like appearance. It is planted in spring after the last frost and grows relatively quickly, flowering six to eight weeks from seeding.

The common name of pot marigold originated from the gold flowers that bloomed during the festivals of the Virgin Mary in Renaissance times (mary + gold = marigold). Ancient Greek, Roman, Arabic, and Indian cultures used calendula as a medicinal herb and as a dye for fabrics, food, and cosmetics. Today, gardeners grow these plants for their cheery flowers and profuse blooming habit. Though they most commonly are seen in varieties with yellow, orange, and red flowers, you can also find them in subtle shades of pink and cream.

Common Name	Calendula, pot marigold, common marigold
Botanical Name	Calendula officinalis
Family	Asteraceae
Plant Type	Perennial, annual
Mature Size	1-2 ft. tall, 1-2 ft. wide
Sun Exposure	Full, partial
Soil Type	Well-drained
Soil pH	Neutral
Bloom Time	Spring, Summer, Fall
Flower Color	Yellow, orange, red, white, pink
Hardiness Zones	2a-11b (USDA)
Native Area	Mediterranean

Calendula Care

Calendula is primarily an annual unless you live in hardiness zones 9 to 11, where it can be grown as a perennial.

It is easy to grow from seeds directly sown in the garden or containers. Plant seeds indoors in early spring and repot or transplant sturdy seedlings after the danger of frost has passed. Calendula will tolerate poor conditions but grows best when it has rich soil. Once established, it doesn’t need much water or fertilizer to grow. Calendula is a full sun plant, however, it’s not a fan of sweltering hot temperatures and might start wilting in intense heat.

Pinching back young plants will promote more compact, bushy growth and prevent the plants from becoming leggy. Deadhead the old flowers to encourage reblooming.

Light

Calendula generally prefers full sun, but it sometimes languishes during the hottest months unless it receives some afternoon shade.

Soil

Like most members of the daisy family, calendula needs well-drained soil high in organic material. Dense, wet soils can cause the roots to rot. This plant tolerates a wide range of soil pH but prefers slightly acidic to neutral soil (6.0 to 7.0).

Water

Water frequently until the plants are established. Mature plants thrive on only occasional watering. Avoid too much water with these plants.

Temperature and Humidity

Calendula prefers mild summer temperatures and may die away by the end of summer in very hot climates.

A hard freeze will kill the plants. If you expect some frost for a day or so, you can protect the plants with a frost blanket overnight and uncover as the sun warms up the air the next day. Three to four inches of mulch will also protect the plants from cold temperatures.

Fertilizer

Calendula does not need much in the way of feeding. If planted in fertile garden soil, it requires no additional feeding at all. Marginal soils may require feeding with a balanced, water-soluble fertilizer, but over-feeding can make the plants leggy and spindly.

Container plants require monthly feeding with a diluted, balanced fertilizer.

Calendula Varieties

There are numerous cultivars of Calendula officinalis. Popular varieties include:

‘Pink Surprise‘: Ruffled gold and yellow flowers, sometimes with pink edges and dark apricot centers
‘Touch of Red‘: Flowers with a mixture of orange and red shades with red-tipped petals
‘Greenheart Orange‘: Flowers with orange petals surrounding lime-green centers; a very unusual-looking plant
‘Citrus Cocktail’: A compact, short plant with yellow and orange flowers; works well in containers
‘Dwarf Gem’: A compact variety with double-petal blooms of orange, yellow, and apricot; another good variety for containers
‘Prince‘: A tall variety that is heat-tolerant with orange and yellow blooms.
‘Golden Princess‘: Bright yellow blooms with a contrasting black center.

Harvesting Calendula

Although some people find the peppery taste somewhat bitter, the flowers and leaves of calendula can be used as edible flowers in salads and other recipes, either fresh or dried. The petals can also be used to create a rich yellow dye.

Collect calendula flowers in the late morning, after the dew has dried. Pick flowers when they are fully open. To dry the flowers, spread out the cut flower heads on a screen in a dry, shady spot. Turn them occasionally until they are papery dry, then store them in canning jars until ready to use.

How to Grow Calendula From Seed

Calendula is very easy to grow from seeds, which easily germinate and sprout. Seeds collected from the flowers can be saved and replanted; the plants will also readily self-seed in the garden.

Start calendula seeds indoors in a seed starter mix about six to eight weeks before the last frost date. Or, you can sow them directly into the garden just before the last spring frost date. Most plants bloom within two months of seeding. These plants very often self-seed in the garden; don’t mistake the seedlings for weeds.

Potting and Repotting Calendula

Although the “pot” in the common name “pot marigold” refers to this plant’s traditional use in cooking, calendula is also commonly planted in pots, where it thrives. Most varieties grow well in containers, particularly shorter cultivars.

Use any well-draining, organic potting soil, or make a mixture with a blend of half garden soil and half compost. Make sure the pot has plenty of drainage holes since this plant does not like to be soggy. Potted specimens need regular feeding with a balanced fertilizer.

Common Pests & Diseases

Calendula has no serious insect or disease problems. The plant can sometimes be susceptible to powdery mildew, which can be remedied by good air circulation.

Slugs and snails may feed on the plants, especially when they are young. Keep the ground clear of debris to minimize slug and snail damage. Aphids and whiteflies can sometimes be a problem. To control them, spray them with water or treat them with insecticidal soap.

Watch The Healing Powers of Calendula on YouTube

FAQ

Is calendula toxic to dogs?
Calendula is not toxic to dogs and cats1.
Is calendula a good companion plant?
Calendula is an excellent companion plant for a vegetable garden because it attracts pollinators such as bees and bumblebees, as well as beneficial insects. The bright blooms are a favorite of butterflies.
When should I collect Calendula seeds?
In the late summer or early fall, instead of deadheading your calendulas, leave the faded flowers on the plant until the petals have shriveled and fallen off and the remaining flower heads with the seeds have become dry and turned tan in color. These are the seeds you want to collect for starting the calendula from seed in the following spring.

Parts Used

The dried petals of the calendula plant are used for medicinal purposes.

Medicinal Uses and Indications

Today, calendula is not usually taken by mouth. The exception is when it is used in extremely small amounts in homeopathic preparations. Calendula is usually applied topically, to the skin.

Burns, cuts, and bruises

Calendula tinctures, ointments, and washes are often applied to the skin to help burns, bruises, and cuts heal faster, and to fight the minor infections they cause. Calendula cream is also used to treat hemorrhoids. Animal studies show that calendula helps wounds heal faster, maybe by increasing blood flow to the wounded area and by helping the body make new tissue. No scientific studies are examining whether calendula works in humans, but using it on your skin is considered safe.

Professional homeopaths often recommend using ointments with calendula to heal first-degree burns and sunburns.

Dermatitis

Early evidence suggests that calendula may help prevent dermatitis, and skin inflammation, in people with breast cancer who are undergoing radiation therapy, however, other studies show no effect. Calendula is also a safe and effective remedy for diaper rash.

Ear infection (otitis media)

Ear drops containing calendula are sometimes used to treat ear infections in children. A few scientific studies have found no side effects. More research is needed to determine whether calendula helps treat ear infections.

Available Forms

Fresh or dried calendula petals are available in tinctures, liquid extracts, infusions, ointments, and creams.

Calendula products should always be protected from light and moisture, and should not be used after 3 years of storage.

How to Take It

Pediatric

Use only topical and homeopathic preparations for children.

For homeopathic dosages, consult a licensed homeopath.

Adult

Speak to your doctor regarding dosing instructions.

Precautions

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.

Calendula is generally considered safe to use on your skin. DO NOT apply it to an open wound without a doctor’s supervision. People who are allergic to plants in the daisy or aster family, including chrysanthemums and ragweed, may also have an allergic reaction to calendula (usually a skin rash).

Pregnant and breastfeeding women should not use calendula. In theory, calendula could interfere with conception, and possibly cause miscarriage, so couples trying to get pregnant should not use calendula.

Possible Interactions

There are no known scientific reports of interactions between calendula and conventional or herbal medications. In theory, taking calendula orally may interact with the following medications, so talk to your doctor before combining these drugs with calendula:

Sedatives
Medications to treat high blood pressure
Medications to treat diabetes

Supporting Research

Akhtar N, Zaman SU, Khan BA, Amir MN, Ebrahimzadeh MA. Calendula extract: effects on mechanical parameters of human skin. Acta Pol Pharm. 2011;68(5):693-701.

Alnuqaydan AM, Lenehan CE, Hughes RR, Sanderson BJ. Extracts from Calendula officinalis offer in vitro protection against H2O2-induced oxidative stress cell killing of human skin cells. Phytother Res. 2015;29(1):120-4.

Barajas-Farias LM et al. A dual and opposite effect of Calendula officinalis flower extract: chemoprotector and promoter in rat hepatocarcinogenesis model. PLanta Med. 2006;72(3):217-21.

Basch E, Bent S, Foppa I, et al. Marigold (Calendula officinalis): An evidence-based systematic review by the Natural Standard Research Collaboration. J Herb Pharmacother. 2006;6(3-4):135-59.

Duran V, Matic M, Jovanovc M, et al. Results of the clinical examination of an ointment with marigold (Calendula officinalis) extract in the treatment of venous leg ulcers. Int J Tissue React. 2005;27(3):101-6.

Fronza M, Heinzmann B, Hamburger M, Laufer S, Merfort I. Determination of the wound healing effect of Calendula extracts using the scratch assay with 3T3 fibroblasts. J Ethnopharmacol. 2009 Dec 10;126(3):463-7.

Hematology/Oncology Clinics of North America. Dietary supplement use in cancer care: Help or harm. Hematology/Oncology Clinics of North America. 2008;22(4).

Jimenez-Medina E, Garcia-Lora A, Paco L, Algarra I, Collado A, Garrido F. A new extract of the plant Calendula officinalis produces a dual in vitro effect: cytotoxic anti-tumor activity and lymphocyte activation. BMC Cancer. 2006;6:119.

Kassab S, Cummings M, Berkovitz S, van Haselen R, Fisher P. Homeopathic medicines for adverse effects of cancer treatments. Cochrane Database Syst Rev. 2009 Apr 15;(2): CD004845. Review.

McQuestion M. Evidence-based skin care management in radiation therapy: clinical update. Semin Oncol Nurs. 2011;27(2):e1-17.

Panahi Y, Sharif MR, Sharif A, et al. A randomized comparative trial on the therapeutic efficacy of topical aloe vera and Calendula officinalis on diaper dermatitis in children. Scientific World Journal. 2012;2012:810234.

Pommier P, Gomez F, Sunyach MP, D’Hombres A, Carrie C, Montbarbon X. Phase III randomized trial of Calendula officinalis compared with trolamine for the prevention of acute dermatitis during irradiation for breast cancer. J Clin Oncol. 2004 Apr 15;22(8):1447-53.

Saini P, Al-Shibani N, Sun J, et al. Effects of Calendula officinalis on human gingival fibroblasts. Homeopathy. 2012;101(2):92-8.

Sarrell EM, Cohen HA, Kahan E. Naturopathic treatment for ear pain in children. Pediatrics. 2003 May;111(5 Pt 1):e574-9.

Sarrell EM, Mandelberg A, Cohen HA. Efficacy of naturopathic extracts in the management of ear pain associated with acute otitis media. Arch Pediatr Adolesc Med. 2001;155(7):796-799.

Sharp L, Finnila K, Johansson H, Abrahamsson M, Hatschek T, Bergenmar M. No differences between Calendula cream and aqueous cream in the prevention of acute radiation skin reactions–results from a randomized blinded trial. Eur J Oncol Nurs. 2013; 17(4):429-35.

Calendula Uses, Benefits, Side Effects, and More