Plant Profiles: Calendula and Onions

In his 1826 plans for a botanical garden at UVa, Jefferson wrote that the garden would be "restrained altogether to objects of use, and indulging not at all in things of mere curiosity." Here at the JDG we will follow this objective, focusing only on useful plants that have been historically important for people, and often continue to hold such importance. Calendula and onions, the first two plant species to be started from seed for the JDG, both have many uses, some of them well known, others less so.

Calendula (Calendula officinalis), syn. Pot Marigold, Marygold
Family: Asteraceae

Image from Kohler's Medicinal Plants, by F.E. Kohler (1887)

Missouri Botanical Garden. http://www.illustratedgarden.org

In addition to lending a bright, cheery yellow to the spring and fall garden, calendula has a wide variety of medicinal, culinary, household, and cosmetic uses. Both the flowers and the leaves are edible. The flowers can be boiled to make a yellow dye; they were even used to turn cheese yellow at one time. Valued for its soothing, healing, and antiseptic properties, calendula can be used in ointments for wounds, varicose veins, and insect bites, in softening skin creams, in healing mouthwashes, and in aromatherapy, just to name a few. While it is not known if Jefferson found calendula useful for these reasons, he did note sowing "Marygold" on April 2, 1767, at Shadwell. In fact, the seeds started for the JDG were recently collected from the gardens at Monticello.

Onion (Allium cepa)

Family: Liliaceae

Image from Flora von Deutschland, Osterreich und der Schweiz,
by Otto Wilhelm Thome (1885)
http://www.biolib.de

While Jefferson only noted growing marygolds, or calendula, once in his Garden Book, the planting of onions appears with much more frequency (1794, 1809, 1812, etc.). Certainly the onion was appreciated as a culinary staple at Monticello during Jefferson's day, but was it also grown for its antiseptic and diuretic qualities and use as a dyestuff? Mrs. Grieve, in A Modern Herbal (originally published in 1931), notes that "a roasted Onion is a useful application to tumours or earache." This particular method may not be gaining in popularity anytime soon, but you never know! Instead of discarding or composting your onion skins, try making a dye from them; depending on the mordant (used to set the dye), the resulting color can vary from orange to a deep yellow. At the JDG, we are starting our onions from seed because of the wider variety available, as compared to onion sets. This year we are trying 'Jaune Paille des Vertus,' introduced around 1793, from Baker Creek Heirloom Seeds.


Just three weeks after sowing the calendula and onion seeds for the JDG, it was time to transplant the seedlings into larger pots. While the other students in the Winter Gardening short-course transplanted seedlings such as kale, wong bok, kohlrabi, leeks, thyme, and sage for future planting in the Hereford Farm Garden, Kaela potted up the calendula and onions that she has been tending for the JDG.

Nice work, Kaela!

Elaine, the course instructor and Hereford's garden manager, lends a hand.

Danielle and Deanna brave the dropping temperature to get their seedlings transplanted.

We hope to plant our calendula and onions in the garden mid-late March, depending on both the weather and our ability to construct all of the new beds by then! Check back soon to see the exciting garden plan designed by two landscape architecture graduate students!

Sources consulted:

1. Bremness, Lesley. The Complete Book of Herbs. New York: Viking Studio, 1988.
2. Grieve, Maud. A Modern Herbal. Darien, CT: Hafner Publishing Co., 1970.
3. Jefferson, Thomas. Thomas Jefferson's Garden Book. Edited by Edwin Morris Betts. Charlottesville: Thomas Jefferson Memorial Foundation, 1999.
4. Sumner, Judith. American Household Botany. Portland, OR: Timber Press, 2004.

*Please note: The above information is for educational purposes only. Consult a qualified practitioner before use.