Marigolds are popular in many gardens as an abundantly flowering ornamental plant. Find out here what other benefits marigolds have and how to grow them yourself.
Aside from being attractive flowering plants, marigolds have lots of other benefits: they are edible and repel pests. Here is our guide to marigolds with some tips on choosing varieties, growing from seed and how to use them.
- Marigolds: origin, flowering time and characteristics
- The most beautiful marigold varieties and species
- Planting marigolds: location, sowing and pricking out
- Marigold care measures
- Propagating marigolds
- Are Tagetes winter hardy?
- Marigolds and pests
- Use in the kitchen: are marigolds edible?
Marigolds: origin, flowering time and characteristics
Marigolds (Tagetes) belong to the daisy family (Asteraceae) and originate from the northern part of Central America, mainly Guatemala and Mexico. The genus is estimated to have 50 to 60 species, some of which are cultivated in Europe as annual ornamental plants. For the Mexican festival, the Day of the Dead, orange marigolds are used to decorate graves. This is why they are sometimes called flowers of the dead.
Tagetes can be annual or perennial plants and can grow upright or bushy. Depending on the species and variety, they can grow anywhere from 20 cm up to 3 m tall. Marigolds usually have pinnate, dark green leaves with a strong, aromatic fragrance. The flowering time usually begins in June and lasts until October, but some species do not flower until autumn. The flowers can be single or double petalled and are arranged in clusters or individually on long flower stems. Marigold flowers are often multicoloured with yellow, orange, red and/or white. After pollination, the long marigold seeds, called achenes, form. As is typical for plants in the daisy family such as dandelion (Taraxacum officinale), marigold seeds also form a kind of elongated, white parachute called a pappus, to help disperse the seeds in the wind.
Are marigolds bee-friendly? The single-flowered marigolds in particular attract bees and other pollinating insects. In midsummer, blooming marigolds are a welcome source of food.
The most beautiful marigold varieties and species
Among the marigolds, there are many different ornamental and edible species. Some of the most popular in home gardens are Tagetes erecta hybrids and Tagetes patula. Tagetes tenuifolia are also becoming increasingly popular. Here are some of the most common species and their most beautiful varieties.
- Mexican marigold or African marigold (Tagetes erecta): Annual marigolds with a height of 30 to 80 cm. The flower heads are often very large and have many petals. However, there are also varieties with single flowers. This includes dyer’s marigold − its orange flowers were used to dye wool and food yellow. Many varieties of Tagetes erecta are hybrids and labelled as Tagetes x erecta. Popular varieties include the white marigold ‘Arctic’ or the dwarf forms Tagetes ‘Strawberry Blonde’ and Tagetes ‘Bolero’ with a height of just 20 cm.
- Irish lace marigold (Tagetes filifolia): The bushy Irish lace marigold grows about 20 cm high and forms lots of narrowly pinnate, sweet liquorice flavoured leaves. It produces tiny, white inconspicuous flowers in autumn.
- Lemmon’s marigold (Tagetes lemmonii): Perennial tagetes species growing to about 40 cm tall. It flowers very late in autumn and through until spring when overwintered in the right location. Lemmon’s marigold leaves and flowers are edible with a spicy-sweet, lemon flavour.
- Mexican tarragon (Tagetes lucida): Perennial marigold with an intense aroma like a blend of tarragon, aniseed and fennel. This yellow marigold grows to a height of about 80 to 100 cm and is hardy to about -6 °C. The Aztecs used this herb to flavour food and for religious rituals.
- Wild marigold (Tagetes minuta): Up to 3 m tall with very large, citrus-scented pinnate leaves. It is also known as ‘huacatay’ in Peru and is used as a spice in a variety of Mexican dishes.
- French marigold (Tagetes patula): A species of marigold that remains small at a height of just 20 to 25 cm. Hybrids of Tagetes x patula are common. The variety ‘Carmen’ displays deep orange-red, double-flowered blooms, while other varieties, such as ‘Mr. Majestic’, form single, yellow and red striped petals. ‘Bambino’ forms bicoloured flowers in yellow and orange, while ‘Durango Red’ is cherry-red and double-flowered. Tagetes patula are particularly effective against harmful nematodes.
- Signet marigold or lemon marigold (Tagetes tenuifolia): About 40 cm tall marigold species with small, pinnate leaves and lots of single flowers. These are edible and offer a refreshing citrus aroma that varies between lemon, tangerine and blood orange depending on the variety. Slugs are not very attracted to this species − in fact, they are often repelled by it. Varieties such as ‘Starfire’, ‘Lemon Gem’ and ‘Luna Orange’ and rather attractive with a multitude of small flowers in light yellow, orange or red.
Planting marigolds: location, sowing and pricking out
Marigolds are ideal for planting in window boxes, as a companion plant in a vegetable patch or as a border plant along the edge of garden beds. Keep a spacing of 20 to 30 cm between plants. If planting in groups, the distance between the plants should be 15 to 20 cm. Find out what else to consider when planting marigolds below.
The right location for marigolds
Marigolds prefer a sunny to partially shaded, warm location. They thrive in well-draining, humus-rich soil. When planting in pots and window boxes, use a loose, nutrient-rich potting soil, such as our Plantura Organic Flower Compost. This compost stores moisture well and releases it to the plant roots as needed. In addition, the nutrients it contains provide the young marigold flowers with everything they need in the first few weeks after planting.
When to plant marigolds
Marigolds are frost-sensitive and generally grown as annuals. They should, therefore, be started on a warm windowsill and not planted outdoors until mid-May, after the last risk of frost has passed.
Planting marigold seeds
It is best to sow marigold seeds indoors and to then plant them outside from May onwards. By starting the seeds indoors on a warm, bright windowsill, they will flower as early as June. Alternatively, you can sow the seeds directly outside in May. However, marigolds sown in May will not start flowering until much later. For starting indoors, sow the marigold seeds between January and March. Fill a suitable growing container with nutrient-poor sowing soil and scatter the seeds on the surface. Then, water and ensure the soil is thoroughly moist. Marigolds need light for germination, so their seeds should not be entirely covered with soil and only pressed down lightly. At 18 to 20 °C and with sufficient moisture, the seeds will take about two to three weeks to germinate.
Marigolds as green manure: In a diverse flower seed mixture, annual marigolds can also be sown as green manure to improve the soil and serve as a food supply for bees. We recommend the signet marigolds (Tagetes tenuifolia), which provides food for pollinating insects with their abundance of single flowers. For these marigolds to flower, sow them directly outdoors from April onwards.
Pricking out Tagetes
As soon as the seedlings develop their first true leaves, you can prick them out and transplant them into individual pots. With the exception of dwarf varieties, the marigold plants are about 5 to 8 cm tall at this time. To stimulate growth, transplant the Tagetes into nutrient-rich potting soil. Simply use a pricking out dibber or stick to gently transplant the seedlings and their delicate roots.
Marigold care measures
In general, marigolds are easy to care for. Straight after planting, however, it is best to put in place some kind of slug and snail guard, as the molluscs love marigolds.
In summer, they need to be watered regularly, especially when grown in pots. When watering, avoid getting any water on the foliage or flowers − moisture on the plant can lead to the spread of fungal diseases. Marigolds are often susceptible to grey mould (Botrytis cinerea). If you spot any diseased plants, remove the affected parts of the plants. As for nutrients, marigolds love a good supply of nutrients and will have a long flowering period with the help of a liquid fertiliser such as our Plantura Liquid Flower Food. Simply applied when watering, the nutrients from the fertiliser flow directly to the roots. To encourage the plant to produce new flowers, deadhead the marigolds throughout summer. This can extend the flowering period by a few weeks.
Tip: The leaves of marigolds, and especially the plant sap, can cause rashes and blisters (phototoxic contact dermatitis) on people with sensitive skin if exposed to the sun after contact with the plant. It is therefore best to always wear gloves when planting and tending to marigolds.
Marigolds are propagated from seed. The best time of year to collect marigold seeds is in autumn. Annual marigolds begin to die back and dry out in late autumn. Harvest the brown seed heads from these plants between September and October. Allow them to dry out indoors at room temperature for a few weeks before freeing the seeds from the flower capsules. Store the seeds in a dark, dry and cool place. Stored in this way, marigold seeds can germinate for several years to come.
Are Tagetes winter hardy?
Marigolds are generally not winter hardy. Annual species die in autumn, but marigold perennials, such as Tagetes lemmonii and Tagetes lucida, are hardy to a certain extent. They can tolerate temperatures just slightly below zero. These species have to overwinter in frost-free, cool and bright locations (i.e. in a conservatory, greenhouse or garden shed). To avoid mould, only water your perennial marigolds sparingly in winter.
Marigolds and pests
In addition to their aromatic citrus scents, Tagetes produce other compounds that they release into the soil through their roots. These root secretions are quite effective in driving away soil-borne pests, such as harmful species of nematodes. Together with the pot marigold (Calendula officinalis), which also drives away nematodes, they are an essential in any vegetable patch. In the greenhouse, underplanting with marigolds repels whiteflies (Aleyrodidae), so they make great companion plants for your tomato crop. Their attractive flowers also attract pollinators to the tomato blossoms.
Use in the kitchen: are marigolds edible?
Marigolds are edible and their flowers and leaves are valuable in herbal medicine. The flowers of Tagetes patula are used to treat a wide range of conditions from night blindness to hiccups and diarrhoea. The aromatic citrus-scented parts of the plant are used as herbs for seasoning and in tea blends. The flowers make for beautiful edible garnishes and are also for colouring rice and in baking.
A close relative of the marigold is the zinnia. Discover the most beautiful varieties of this popular annual flower, and get tips on sowing, care and propagation.