Calendula

Calendula officinalis is an edible flower that can add color and attract honey bees to your garden.

Believed to be native to Europe, Calendula officinalis has been grown by people for so long and in so many locations, it is hard to tell for sure.

‘Calendula officinalis’ (Berdan) CC BY-SA 3.0

Sunny yellow and orange calendula create lovely borders that bloom throughout most of the year. Blossoms look similar to daisies because both are members of the sunflower family, or Asteraceae.

Many faces of marigold

Most marigolds sold in retail outlets are members of the Tagetes genus. Tagetes, or simply ‘marigolds’, are native to the Americas. Tagetes are known for their pungent aroma that may (or may not) deter deer, rabbits, voles, and other pests from grazing on your garden plants. Tagetes marigolds also attract and then kill nematodes.

​Today’s topic, Calendula officinalis, will not protect your plants from herbivores or nematodes, but they have their place, having been used as food and medicine for centuries.

'Tagetes erecta' (Ezhuttukari) CC BY-SA 3.0

Pot marigold description

Unlike the Tagetes genus of marigold, which have leaves that appear alternately along a stem, pot marigolds have slightly hairy leaves that are arranged in a spiral around the stem. They are short-lived perennials, typically grown as annuals, that grow 18 to 30” tall, with 2” flowers. Flowers are bright yellow or orangish-yellow, with ray florets and disk florets, common to sunflowers. Pot marigold’s curved seeds are actually dried fruits, called achenes.

Calendula seeds (H. Zell) CC BY-SA 3.0

Pot marigold as an attractant

In addition to looking lovely as a border plant, or in a parterre, Calendula officinalis will attract important pollinators, such as honey bees to the garden. Unfortunately, they will also attract cabbageworm butterflies, large yellow underwings, an invasive moth of the cutworm variety, and setaceous Hebrew character moths, whose larvae feed on a number of popular garden plants.

Pot marigolds as food

Pot marigold flower petals have a tangy, peppery flavor. Traditionally added to German soups and stews, pot marigold is also added to herb butters and cheeses, or chopped and used to garnish deviled or scrambled eggs, fish dishes, or steamed vegetables.

Pot marigold flower petals add color and tang to salads. If you add marigold flower petals to rice, while cooking, the rice will turn yellow. For this reason, it is also known as Poor Man’s Saffron. Farmers have fed marigolds to chickens for years to make the yolks a deeper yellow.

One variety of pot marigold, ‘Mexican Mint’, has the flavor of tarragon. It is also known as Texas tarragon. Pot marigold petals also make a delightful tea.

Pot marigold at the beach (Public Domain)

Pot marigolds as medicine

Pot marigolds also have medical merit. Research has shown that tinctures of pot marigold are used today to treat skin irritations and burns, to speed healing, and to control bleeding. [I wonder how they would look growing next to some aloe vera - just to keep the medicinals together.] This is not my area of expertise, and I won’t make any personal claims, but it is interesting to see how, every once in a while, those old treatments hold true. That being said, some people are allergic to pot marigolds.

How to grow pot marigolds

Pot marigolds are easy to grow from seed and they tend to be drought tolerant. Start seeds in small pots, only lightly covered with soil. Keep the soil moist, but not soggy, until germination occurs. Then, move plants to a sunny location with good drainage. Calendula may need protection from scorching summer afternoon sun, and they can be grown in containers, or on windowsills. Marigolds readily self-seed.

Calendula pests and diseases

While these plants are relatively trouble-free, they may become infected with powdery mildew, root rot, and smut. They are also susceptible to Alternaria leaf spot, aster yellows, charcoal root rot, cottony rot, cucumber mosaic, gray mold, Pythium root rot, root knot nematodes, rust, southern blight, spotted wilt (from the tomato spotted wilt virus), stem rot, and Verticillium wilt. I couldn't find any pests that significantly bother pot marigolds.

Many of these diseases can be prevented by providing good drainage and air flow, so top dress soil regularly with organic matter, space plants with mature sizes in mind, and avoid overhead watering.

So, do you know if your marigolds are edible or not now? This poem may help:

​Tagetes are death to nematodes 
   Alternate-leaved armies 
      Our native marigolds
While edible Calendula 
   Can ease a burn or rash
      Spiral-leaved pot marigolds