Calendula is a flowering herb known for its cheery, orange-yellow exterior and array of medicinal uses. Its name stems from the latin word “kalendae“, which translates to “first of the month”, and has been known to speckle the landscape of its native terrain (the Mediterranean and parts of Asia) near the first of many months. We know it’s been used in natural healthcare since the 12th century , although its remedies may have been around for much longer. It shares some common names with the ornamental marigold, being called “Pot Marigold”, “Poet’s Marigold”, “Mary’s Gold”, and simply “Marigold” . While they share the family “Asteraceae” Calendula is different than the common marigold (genus tagetes) in both appearance and medicinal properties.
It’s very resilient in neglected conditions and thrives under full sun to part shade. It grows well in pots with well-draining soil and ample access to organic material. It reseeds very quickly, spreading itself wherever you allow it to. During the most intense, hot days of Summer, it is recommended to provide some shade and extra water, but in terms of care, calendula is easy to grow and maintain. It ranges in colour from bright orange-red to soft cream and apricot, but always seems to hold onto a soft touch of orange. It is a perennial in the right environment, but can be an annual if you live in cooler regions.  It is a very beginner friendly herb to grow, and its potential as a medicinal herb makes it a wise choice for budding herbalists.
There are about 20 different species in the genus “Calendula“. The species used most often for medicine include, “Calendula officinalis Linn., Calendula arvensis Linn., Calendula suffruticosa Vahl., Calendula stellata Cav., Calendula alata Rech., [and] Calendula tripterocarpa Rupr” (A Review on Phytochemistry and Ethnopharmacological Aspects of Genus Calendula). To simplify my research, I will only be diving into Calendula Officinalis, which has been evaluated in scientific studies aimed at pinning down the properties of this ancient remedy. For more information on the various species of calendula, check out my sources; there is so much information to dig through in those pages.
Calendula Officinalis in Traditional Herbalism
Out of all the species of calendula, calendula officinalis is the most common and widely used. According to The Modern Herbal Dispensatory, Calendula is often used to treat eczema and hemorrhoids, topically, and is an excellent remedy for “Crohn’s disease, colitis, and gastritis” when taken orally. In traditional herbalism, it is used as a topical anti-inflammatory, as a conduit for finding balance in (and symptom relief of) menstrual cycles, and even for conjunctivitis, aka “pink eye” . Others make use of it for gall and kidney stones, perhaps spurred by its anti-inflammatory qualities.  Many herbalists use it for its antiseptic properties, and to disinfect wounds and abrasions. Even bruising can be treated with calendula officinalis, used here to reduce edema and pain. In fact, most painful, swollen, and inflamed skin ailments have been treated with Calendula, including insect stings and bites, burns, cuts, rashes, bed sores, and more (Engels). There are some herbalists today who use calendula essential oil as a treatment for vaginal yeast infections . It has also been used as a means to reduce fever, or cause sweating during one, acting here as an antipyretic, similar to how many people use Tylenol. It is often prepared in oil infusions, tinctures, and other extracts. It can also be ingested whole for both medicinal and culinary benefits, although most use today is in topical preparations[2,3]. It is an herb used to treat ailments in the pharyngeal mucosa, also known as the mouth and throat. It has also been used in treating stress, anxiety, and insomnia.
Calendula Officinalis in Scientific Studies
According to St. Luke’s Hospital’s page on Calendula in alternative medicine, it is known to have “high amounts of flavonoids”, which are antioxidants produced by plants. These antioxidants prevent cells from being damaged by free radicals. In addition, “Calendula appears to fight inflammation, viruses, and bacteria,” making it an incredibly useful herb (VeriMed Healthcare Network). The oil and extracts of calendula in particular are noted to be “antimicrobial, anti-inflammatory, antibacterial, antifungal, antitumor, cytotoxic, anti-HIV, and wound healing” (Engels). Even the seeds of the calendula plant have potential medicinal benefits. Their high calendic acid content show strong antioxidant properties. Many traditional uses of calendula hold up very well throughout the studies and trials done to find these properties conclusively, effectively giving herbalist the green light to keep using and enjoying calendula as they have always done.
While researching calendula and these studies, I ran across some interesting examples. I really recommend reading my sources cited for all of the details, but in several different studies, calendula was observed to help with things such as venous leg ulcers, inflamed nipples, prevent dermatitis associated with chemotherapy radiation, and is even noted as “healing ulceration[s] caused by herpetic keratitis (inflammation of the cornea and conjunctiva caused by herpes virus type I)” (Engels)[2,3].
The evidence for calendula being a potent medicine is strong, and its safety record is equally as robust. The only dangers I could find for calendula were allergic reactions and potential interactions with medications that are sedatives, made to control diabetes, or meant to balance blood pressure, and the ever-so-common warning for pregnant and breastfeeding women to steer clear. So, if you’re allergic to any other plant in the Asteraceae family, stay away from Calendula, but barring interactions for internal application or pregnancy concerns, it’s a very safe herb to be handling and using.
A Note on Calendula Arvenis
I don’t want to write another entire section or two for Calendula arvenis, but I do want to note that it has some remarkable uses. In some of the aforementioned explorations into the benefits of calendula, they recorded that calendula arvenis was an effective treatment against Staphylococcus aureus (staph infection), and that when aerial parts of it were in a saponin, they showed “hemolytic activity invitro and anti-inflammatory activity against carrageenan induced paw edema in rats”( Arora, D., Rani, A., & Sharma, A. ). It was also noted that “saponins showed antimutagenic activity against benzo (a) pyrene 1 μg and mutagenic urine concentrate from a smoker (SU)”, which are all findings worth looking into ( Arora, D., Rani, A., & Sharma, A. ).
Overall, Calendula is powerful herb with little drawbacks. The small amount of scientific evidence we do have on it show promising results, and align well with traditional use. I’ve been experimenting with my own calendula products, focusing mainly on its usefulness in irritated, angry skin.
All of my sources are linked below and are also formatted as PDFs! Simply skip to the second list to download those. Feel free to share your own sources if you have any you recommend reading! Bye!
Whelan, R. (2011). Calendula. Richard Whelan ~ Medical Herbalist. https://www.rjwhelan.co.nz/herbs%20A-Z/calendula.html.
Arora, D., Rani, A., & Sharma, A. (2013, October). A Review on Phytochemistry and Ethnopharmacological Aspects of Genus Calendula. Pharmacognosy Review. http://www.phcogrev.com/article/2013/7/14/1041030973-7847120520.
Engels, G. (2008). Calendula – American Botanical Council. https://www.herbalgram.org/resources/herbalgram/issues/77/table-of-contents/article3229/.
VeriMed Healthcare Network. (2015, June 22). Calendula | Complementary and Alternative Medicine . Calendula | Complementary and Alternative Medicine | St. Luke’s Hospital. https://www.stlukes-stl.com/health-content/medicine/33/000228.htm.
Badgett, B. (2021, April 26). Calendula Flower: How to Care for Calendula Plants in the Garden. Gardening Know How. https://www.gardeningknowhow.com/ornamental/flowers/calendula/growing-calendula.htm.
Easley, T., & Horne, S. H. (2016). Chapter Thirteen: Single Herbs; Calendula. In The modern herbal dispensatory: A medicine-making guide (pp. 200–201). essay, North Atlantic Books.