How to Grow Calendula: Brilliant Flowers that Heal

With their vibrant colors and joyful blooms, calendulas can immediately brighten up a room. Commonly called pot marigold, these cheerful flowers, often appearing in clusters of orange or yellow, are sure to remedy a dull spot or plain vegetable patch. A highly versatile plant, calendulas have been used to ward off pests, to heal ailments, and attract beneficial pollinators throughout history. The leaves and flowers are edible and have been used for both culinary and medicinal purposes. Emitting a spicy taste reminiscent of saffron, the dried petals can be used as a seasoning or as a saffron substitute in tea. In early colonial America, the dyes of the calendula plant were used to color butter and cheese.

Basic information

Scientific Name	Calendula
Common Name	Calendula, pot marigold
Light	Full sun to partial shade
Soil Type	Most soil types
Water	Regular watering
Days to Harvest	6 – 8 weeks
Fertilizer	Not necessary
Hardiness Zones	Annual planting in zones 2 – 9

Types of Calendulas

With over 25,000 species, calendulas belong to the Asteraceae family, one of the largest flower families. Though they are referred to as marigolds, they are not true marigolds. Native to southern Europe, it has since been naturalized worldwide. From imperial yellow to creamy peach, calendulas range in color from subtle to vibrant. Below are some types of calendulas to choose from: 

• Touch of Red: Beige pink petals with raspberry red tips. 

• Porcupine: A striking annual with dark green foliage and blazing-orange, quilled flowers.  
• Pink Surprise: Radiant apricot-colored blooms with unique double florets. 
• Golden Emperor: A regal heirloom variety featuring profuse, enormous blooms of canary yellow.
• Orange Flash: Radiant apricot-colored blooms with unique double florets.

Benefits of Calendulas

Companion Plant

Calendulas are an effective pest control method for some vegetable plants, particularly for tomato and carrots, which are susceptible to harmful nematodes. Calendulas, along with certain varieties of marigolds and chrysanthemums, have been shown to suppress nematode activity. To improve productivity and maximize space, interplant calendulas with certain vegetables and flowers, including tomatoes, peas, carrots, and spring salad vegetables.

Medicinal Uses

In ancient times, calendula was used by the Romans in religious ceremonies and for medicinal purposes. Known to have anti-inflammatory and antioxidant properties, calendulas have been used for wound healing and skin health. The oil, a key ingredient in salves, balms, and tinctures, is used to treat burns, bruises, cuts, and minor infections. For medicinal preparations, use only dried flowers, which contain the useful part of the plant and are high in antioxidant compounds.

Ornamental Uses

A highly ornamental plant, calendulas are ideal for virtually any landscaping endeavor, from container gardening to application as a ground cover. For an elegant flower bed, try planting calendulas with asters, lavender, roses, and geraniums. During the summer, the flowers can be preserved in ice cubes for added appeal in a beverage. Use them as decorations in salads, smoothies, soups, and deserts. Known as “poor man’s saffron,” calendulas can be harvested for dye, imparting a beautiful golden hue that is used to color butter, cheese, and textiles. 

Conditions for Growing Calendulas

Calendulas are drought tolerant once established and can tolerate in poor or average soil. A prolific spreader, they will self-seed if not deadheaded regularly. They are a low-maintenance plant that blooms all season long. Butterflies, bees, and other beneficial insects are drawn to the fragrant flowers, making them ideal for a pollinator or cottage garden. 

Light

Calendulas need a moderate amount of light – a minimum of 6 – 8 hours daily. Grown in full sun or partial shade, they prefer cooler weather and will not perform well during the hot summer months. They can be either sown in spring or fall, during the cooler months after the danger of frost has passed. They can also be sown indoors 3 – 4 weeks before the last frost date in seedling trays. Transplant your calendula outside only after all risk of frost has completely passed, and they have developed several sets of first leaves. 

Soil

While calendulas can tolerate most soil types, they prefer loamy, well-drained, moderately rich soil. Between March and May, sow calendula seeds directly in the ground in a row, allowing 5 inches between seeds. Often planted along the edges of herb, flower, or vegetable beds, they can be virtually grown in any location with soil, including raised garden beds. Calendulas are great companion plants in a vegetable garden because they provide dazzling visual interest, attract beneficial insects, and repel pests. 

Water

Calendulas should be watered frequently until they become established. After planting, mist the garden bed every day for 7 – 14 days until germination. The soil should be kept moist but not completely saturated, which can cause root rot. During hot weather, water 1 – 1 ½ inches once a week. 

Temperature and Humidity

Calendulas don’t fare well under hot weather, blooming best under cool weather with low humidity. In scorching hot climates, they may wither and die. Water in the morning if you notice them wilting. To protect your plants during periods of intense heat, wheel them inside in raised rolling beds. Vego Garden’s Elevated Rolling Bed, with its heavy duty, lock wheels and shelf underneath to store gardening essentials, is a great choice for those with limited space or live in a hot, dry environment. 

Fertilizer

Calendulas do not require much fertilizer, especially when planted in soil rich in organic matter. During the growing season, apply a weak orchid fertilizer following label instructions. If your soil is of subpar quality, adding a water-soluble fertilizer can improve flower growth. They should be fertilized sparingly, as over fertilizing can cause them to become leggy and spindly. 

Pests

While calendulas do not have serious disease or pest problems, they can become a pest magnet. As a result, they are often grown as a sacrificial crop. Sacrificial crops, or trap crops, are deliberately planted with the intention of attracting agricultural pests such as aphids, whiteflies, and thrips so that they do not wreak havoc on more susceptible plants. If you are experiencing aphid or other insect infestations on your vegetables, try planting calendulas as a natural method of pest control. 

On a high note, calendulas also attract beneficial predatory insects, who are drawn to the nectar they provide. These insects will contribute to a flourishing ecosystem as they settle and congregate. 

Occasionally, calendula can become susceptible to powdery mildew if grown in shaded, humid conditions. Powdery mildew is a fungal disease that causes frosty white spots on leaves. Infected plants should be removed and measures taken to provide adequate circulation. Powdery mildew can be treated with a natural fungicide such as sulfur, copper fungicide, or potassium bicarbonate

Harvesting & Pruning 

Calendulas benefit from occasional pruning. If not pruned regularly, they may become weedy. To encourage fuller growth, cut back wilted flowers and discolored foliage. As it contains a high level of medical resins, it is sticky to the touch. You can choose to wear garden gloves to avoid getting the resin onto your hands. 

To harvest calendula, snip or pinch off the entire flower at the stem. For optimal results, harvest in the morning after the dew has dried, when the blooms are partially opened or just opened. Avoid flowers that are beginning to wither or have gone to seed, as they have lost their potency.