Calendula has long been grown in cottage and vegetable gardens. The plant delights not only with its beautiful flower but also its versatility.
Not only is Calendula officinalis valuable to honeybees, wild bees and butterflies due to its high-quality pollen and nectar, we humans can also benefit from it. Read on to find out everything about this plant, including our tips on how to grow it at home as well as how to use it.
Calendula: profile and origin
Calendula, also known as pot marigold, ruddles or common marigold, belongs to the Asteraceae family. The flower has been around for so long that it is impossible to say where it came from with certainty. Botanical studies suggest that it originated in the Mediterranean region and the Crusades may have possibly aided in its spread at the end of the 11th century. Calendula is therefore a neophyte, or a non-native plant. However, because it does not crowd out other plants or proliferate excessively, it is not considered problematic or invasive in the UK.
Nowadays, calendulas grow primarily wherever the soil is nutrient-rich and loose. After flowering, the annual pot marigold forms seed heads that fall and overwinter in the soil, producing new 20 to 60 cm tall yellow-orange flowering plants the following growing season. The non-toxic calendula blooms from June to October and can be used in a variety of ways. For example, you can use common marigold as a home remedy to treat wounds or reduce inflammation.
The most beautiful species and varieties
The different varieties are often only available locally. Here are some particularly lovely varieties of pot marigold available in the UK:
- Calendula officinalis ‘Orange Gitana’: A rather low-growing variety with orange double flowers from May to October
- Calendula officinalis ‘Snow Princess’: Semi-double flowers with creamy lemon petals and darker eye
- Calendula officinalis ‘Orange porcupine’: Well-rounded, orange flowers with unusual slightly curled petals
- Calendula officinalis ‘Neon’: Fully double flowers with brilliant orange petals tipped with burgundy
Aside from Calendula officinalis varieties, there are also other related species that can be both decorative and useful. Calendula arvensis, for example, is considered the ancestor of common marigold and can be grown just as easily.
Calendulas are versatile and can be used as a striking decoration among vegetable crops, as part of a wildflower meadow for insects, or simply grown on their own. You, too, can grow calendula in your garden; here is how.
The right location for calendula
Calendula likes fresh to moist, loamy, nutrient-rich soil. Unfortunately, heavy and waterlogged soils are unsuitable for growing the plant. Sow the seeds in a sunny to semi-shady location outdoors or in a container from March to May, and no later than early autumn. It is easy to grow calendula in a pot and keep it on your semi-shady to full-sun balcony as a useful plant for humans and insects.
Important: If grown in a pot, choose a pot with holes to ensure water drainage. Keep pot marigold seeds moist so that they can germinate.
Sowing pot marigold at a glance:
- Sowing period: April – October
- Germination period: 8 – 14 days
- Germination temperature (optimal): 10 – 20 °C
- Sowing depth: 1 – 2 cm
- Row spacing: 20 – 30 cm, this spacing also applies to other crops
- Plant spacing: Thin out to 25 cm after sprouting
For sowing, use a loose soil with a low nutrient content, as this stimulates root formation and allows the plant to grow optimally. For example, our Plantura Organic Herb & Seeding Compost is ideal for sowing. The perlite in the soil provides a loose soil structure.
Using calendula as green manure against pests
This medicinal plant is not only beneficial to humans and insects, but it can also help improve the soil. For example, if the soil is infested with harmful nematodes (also called threadworms or eelworms), calendula plants act as a natural soil disinfectant against many types of nematodes. Simply sow 1.5 grams of calendula seed per square metre between March and September and let the flowers grow for at least ten weeks before incorporating them into the soil. Companion planting with calendulas is an effective pest control measure for some vegetable plants, particularly as harmful nematodes are common in tomatoes and carrots.
Tip: Not all nematodes are pests. In fact, there are also beneficial nematodes which are useful for organic pest control.
Calendula care: pruning, watering and more
When fully grown, calendulas can withstand some dry spells. However, if the soil is visibly dry, water your plants. At the same time, they do not tolerate waterlogging.
It is important to fertilise your calendulas if they have grown by self-seeding in the same place for several years. When sowing, work some slow-release fertiliser into the seedbed. You will get at least three months of long-term effects from our Plantura Flower Food. Its balanced nutrient composition and slow, steady release of nitrogen, as well as its rather low phosphate and high potassium content promotes healthy, resistant and abundantly flowering calendulas.
This long-stemmed flower is perfect as a cut flower in vases from summer to autumn, bringing the joy of colourful nature into the home.
Feed your calendulas growing in pots every six weeks with a liquid fertiliser. However, pay attention to the nutrient composition – too much nitrogen in the fertiliser significantly reduces flowering. Our Plantura Liquid Flower Food, on the other hand, ensures lush blooms all season long. The contained microorganisms are deposited into the soil with a quick and easy watering application. These in turn promote strong root growth. Our fertiliser’s nutrient composition is specifically developed for flowering plants and provides key nutrients in appropriate amounts.
Calendula care at a glance:
- Water when visibly dry but avoid waterlogging
- Use a long-lasting fertiliser every year in fields and when grown as a perennial in the same location
- Feed calendulas in pots every six weeks
Are calendulas hardy?
Calendula is an annual summer flower that cannot be overwintered. However, if temperatures do not fall below -5 °C, the bright flowers can still be seen. Below this temperature, the plant will stop growing altogether. As a result, calendulas can be considered frost-resistant.
The seeds that the pot marigold scatters at the end of its growing season also survive the winter in the soil. In the spring, these then grow into new seedlings, so that with a little luck you can enjoy the calendula again. If you sow calendulas late in the year, it is likely that they will still be flowering beautifully in winter.
Tip: You can also collect calendula seeds while they are still ripening on the plant. You can reconise mature seeds by the fact that they are dry and that you can easily remove them from the seed pod, which is also dry. You can then grow the flowers from seed elsewhere in your garden or in pots to create a lovely calendula display.
Harvesting calendula: when and how?
The best time to harvest calendula for medicinal purposes is during the flowering period because you need to use fully formed flowers. Here, often only the flower heads are used, which can be easily picked with your fingers. Calendula leaves are particularly interesting to wild herb enthusiasts. You can harvest these throughout the year but take care not to remove all the leaves, so that the plant can regenerate.
The different parts of calendula are used in different ways:
- Leaves: salad ingredient
- Flower heads: salad garnish, natural dye for rice or Easter eggs, steeped in ointments
- Petals: dried calendula tea
- Flower stem and flower: cut flower
Calendulas are insect-friendly plants and bees are often found enjoying their nectar and pollen. For use as a cut flower, cut the most beautiful stems far down, preferably with just freshly opened flowers. Make sure that no leaves are submerged in the vase water.
Calendula: health benefits
The most well-known remedy is probably calendula cream, which you can also make yourself. How to make the cream: lightly boil calendula flower heads with beeswax and sunflower oil. You can also use petroleum jelly or bag balm as a base. Calendula cream is used to heal wounds and treat joint pain. It also helps with pimples, dry skin, and dermatitis, as well as stretch marks.
Is calendula poisonous?
As can be seen in the above sections, the plant is not toxic to humans. Calendula remedies also exist for dogs and horses, such as teas for the digestive system and oils for the coat. Unfortunately, the essential oils found in calendula are toxic to cats.
Calendula is not the only plant that can be used as a home remedy for dry skin. Find out how to moisturise your skin using plants from your home and garden.