Whether displaying bright orange or sunny yellow flowers, calendula (also called pot marigold) is one of the most essential parts of your garden medicine chest: Those aromatic flowering heads can be collected and made into oils and salves to help heal skin injuries of all kinds. Make sure you grow only C. officinalis, and not any of the many “marigolds” (Tagetesspp.) or ornamental varieties that are available. Calendula can grow to almost 2 feet tall, and the flowers tend to open with sunny, dry weather and close in cold or moist conditions.
Growing. Calendula enjoys full sun—or even partial shade, in hot summer regions—and average soil, and has moderate water needs. If flower production dwindles, you can cut back the plants to increase new flower production. Calendula will self-sow yearly in many gardens, and it doesn’t mind crowding. Direct-sow the seed in early spring or late fall, as it can withstand some frost.
Harvesting. Collect the flower heads on hot, sunny days for the highest resin content, and pick them regularly to prevent the plants from putting their energy into seed production. Once that happens, the rest of the flowers will be smaller. Choose flowers that are just opening in the morning before 11 a.m. Dry calendula quickly after you harvest it, and check the center of the flower for dryness. Molding in storage is a problem. Watch for reabsorption of moisture, and keep it in complete darkness.
Preparations and dosage. Use the freshly dried flower heads to make creams, salves, liniments, teas, tinctures, and oils, or add the flower heads directly to your bath to soothe irritated skin. For internal conditions, take 1 to 3 dropperfuls of tincture in a little water several times daily.
Safety. As with other members of the daisy family, some people are sensitive to calendulas because of the sesquiterpene compounds that the plants contain. If you have allergic skin reactions or are sensitive to foods or the environment, start with a low dose of this herb and work up to a full dose, if you don’t experience any reaction.
Healing properties. Use the entire flower head (not just the petals) in preparations for healing cuts, scrapes, burns, diaper rash, sores, ulcers, varicose veins, chapped skin and lips, and insect bites. Salves, oils, creams, and other preparations can be found in drugstores and natural food stores alike. Science shows that extracts of the flower heads have anti-inflammatory and antibacterial effects. And herbalists have long recommended tea infusions of calendula to help heal ulcers in the digestive tract; soothe gallbladder inflammation; and treat enlarged, sore lymph glands.