Calendula (Pot Marigold) Plant Profile

Close up of a Calendula

 itanapunyo / Pixabay

Calendula (Calendula officinalis) is a short-lived perennial in warmer climates, but it is usually grown as an annual flower in garden beds and containers. Although commonly known as pot marigold, calendula is different from the common marigold (Tagetes spp.). It is, however, part of the same Asteracea family, along with daisies and chrysanthemums, with whom it shared the same daisy-like flower appearance.

The common name of pot marigold derives because the gold flowers that bloomed during the festivals of the Virgin Mary in Renaissance times (mary + gold = marigold) were often used in cooking. Today, gardeners simply grow these plants for their cheery flowers and profuse blooming habit. Though they most commonly are seen in varieties with yellow and orange flowers, there are also more subtle shades of pink and cream available. Calendula is commonly used in annual flower beds and container gardening.

Botanical Name Calendula officinalis
Common Name Calendula, pot marigold, common marigold, Scotch marigold
Plant Type Herbaceous perennial flower, usually grown as an annual
Mature Size 1 to 2 feet in height with a similar spread
Sun Exposure Full sun to part shade
Soil Type Average, well-drained soil rich in organic material
Soil pH Prefers 6.0 to 7.0, but tolerates a wide range of soil pH
Bloom Time May to early fall; will rebloom constantly if old blooms are dead-headed
Flower Color Bright yellow to deep orange; creams and pinks also available
Hardiness Zones 9 to 11, but usually planted as an annual in zones 2 to 11
Native Area Unknown; may be a garden creation, not a native species

How to Grow Calendula

Calendula is very easy to grow from seeds or transplants when placed in full sun and planted in ordinary fertile garden soil that is well-drained. Purchased seedlings should be planted after the danger of frost has passed; seeds can be sown just before the last frost date in the spring. 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 in hotter areas, it sometimes languishes during the hottest months unless it receives some afternoon shade.

Soil

Like most members of the daisy family, calendula needs a 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 a slightly acidic to neutral soil.

Water

Water frequently until the plants are established, but 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.

Fertilizer

Calendula does not need much in the way of feeding, and 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 do require monthly feeding with diluted balanced fertilizer.

Propagating Calendula

Calendula is a short-lived perennial that is generally propagated 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.

Varieties of Calendula

There are many varieties and cultivar series of calendula, offering flowers of slightly different appearances. Some popular ones include:

  • 'Radio Extra': This is a tall plant with bright orange, cactus-like blooms.
  • 'Pink Surprise': This plant has ruffled gold and yellow flowers, sometimes with pink edges and dark apricot centers.
  • 'Touch of Red': This has flowers with a mixture of orange and red shades with red-tipped petals.
  • 'Neon': This features double-petaled flowers in bold colors.
  • 'Greenheart Orange': This has flowers with orange petals surrounding lime-green centers; a very unusual looking plant.
  • 'Tangerine Cream': This has double-petaled flowers with bi-color blooms of bright orange and cream.
  • 'Bronzed Beauty': This has cream and peach flowers that grow on tall stems.
  • 'Citrus Cocktail': This is a compact, short plant with yellow and orange flowers; it works well in containers.
  • 'Sherbet Fizz': This has buff-colored flowers with deep red undersides petal tips.
  • 'Dwarf Gem': This is a compact variety with double-petal blooms of orange, yellow. and apricot; another good variety for containers.
  • 'Fruit Twist': This is a variety featuring a mix of single, double, and semi-double flowers in yellow and orange.
Pot Marigold (Calendula officinalis 'Sherbet Fizz')
Chris Burrows/Getty Images

Harvesting Calendula

Although some people find the taste somewhat bitter, the flowers and leaves of calendula can be used in salads and other recipes, both fresh or in dried form. The plant sometimes regarded as a medicinal herb and has been used in topical ointments for cuts and scrapes.

Collect calendula flowers in the late morning, after the dew has dried. Pick flowers when they are fully open and check often because they come and go quickly. To dry the flowers, spread the cut flower heads out 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.

Growing From Seed

Start calendula seeds indoors in seed starter mix about 6 to 8 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 2 months of seeding. These plants very often self-seed in the garden; learn what the seedlings look like so you don't mistake them for weeds.

Growing in Containers

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 do well in pots, although shorter cultivars may be better suited. Use any well-draining, organic potting soil; or you can 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 will need regular feeding with a balanced fertilizer.

Common Pests and Diseases

Calendula has no serious insect or disease problems. They can sometimes be susceptible to powdery mildew (remedied by good air circulation), and slugs and snails may feed on them, especially young plants. Keep ground areas clear of debris to minimize slug and snail damage. Aphids and whiteflies can sometimes be a problem; spraying with water or treating with insecticidal soaps can eliminate them.