- Common name: Marigold
- Botanical names: Calendula, Tagetes
- Family: Daisy (Asteraceae)
- Type: Annuals
- Flowering time: Summer and autumn
- Sowing time: Spring and autumn
- Planting time: May and June
- Height: 30cm-1.2m (1-4ft)
- Spread: 30-45cm (12-18in)
- Aspect: Sun
- Hardiness: H2 to H5
- Difficulty: Easy
Blazing in shades of orange, gold, peach, and red, marigolds inject the garden with warmth and cheer during summer and into autumn. The flower name encompasses two types of plant: Calendula and Tagetes. Both are easy to grow from seed and boast the fascinating ability to attract wildlife and, in turn, stave off pests in the vegetable garden.
There are 12 species of calendula, many of which hail from the Middle East and the Mediterranean. Our native field marigold (Calendula arvensis) has small golden daisies, but the Spanish pot marigold (C. officinalis), which bears large orange daisies, is the main type grown in gardens, with a variety of hybrids readily available. Pot marigolds are excellent cut for the vase and bloom more abundantly, for longer, if regularly harvested or deadheaded. Having big seeds and edible flowers, they are also super plants to grow with children. In ancient Rome and Greece, calendula was used to dye fabric, cosmetics, and food. It was used as a tisane and topical herb in ancient Egypt, and, today, is widely used to soothe irritated skin.
The tagetes genus encompasses 49 species from Mexico and other parts of the Americas, including the garden forms we refer to as African (Tagetes erecta), French (T. patula), and signet (T. tenuifolia) marigolds. The plants exude a delicious, pungent scent, especially when deadheaded (which ensures they flower over a long period). Because of their wildlife benefits, modern gardening favours single-flowered T. tenuifolia and single forms of T. patula. The bushy marigolds we grew as bedding plants in the '70s and '80s were double forms of the so-called African marigold; it is in fact native to Mexico, where it is known as cempasúchitl and used in abundance on the annual Day of the Dead in early November for its believed ability to attract the spirits of passed loved ones. T. erecta is also grown widely in India, to be fashioned into garlands for all manner of celebrations and devotional offerings, but in particular for Diwali (the Hindu festival of lights) in November, when homes and temples glow gold and orange with candlelight and a mass of fragrant marigolds to symbolise the victory of light over darkness.
Which marigolds to grow
The range of pot marigold (Calendula officinalis) varieties on offer includes shades of orange, gold, and white. Arguably the best orange is 'Indian Prince', which has blazing-tangerine daisies on 60-centimetre stems. The apricot cultivars are also beautiful: especially 'Sunset Buff' (45cm) and 'Touch of Red Buff' (60cm), which both produce dusky-pink and peach petals with raspberry-red undersides and chocolate centres. All three are accessible to pollinators, whereas some of the bushier fully double forms have limited or no access to pollen and nectar, making the plants less useful in the garden. They look great growing alongside claret blooms, such as 'Black Cat' scabious and honeywort (Cerinthe major 'Purpurescans').
Opt for single-flowered forms of Tagetes for a contemporary look and to attract beneficial wildlife. The Gem series ('Lemon Gem', 'Tangerine Gem', and 'Red Gem') are excellent signets (Tagetes tenuifolia) that provide months of colour at the edge of the border or in the vegetable patch. Desirable French forms (T. patula) include 'Burning Embers' (50 to 75cm) and 'Cinnabar' (60cm or the Great Dixter tall form can reach a whopping 1.2m).
Three species of Tagetes can be grown as herbs: the annual Tagetes minuta (stinking Roger), which is used to dominate and clear stubborn perennial weeds (such as ground elder and bindweed), can be brewed as an aromatic anti-inflammatory tea; and the annual T. filifolia (Irish lace) and the perennial T. lucida (sweet mace), which both taste of aniseed, can be used as (easier to grow) alternatives to French tarragon. The bold-orange petals of Calendula officinalis are edible and, today, are mostly used to brighten up cakes and salads, but, in the past, they were stirred into stews and soups to impart a golden colour, which is why two of the plant's common names are pot marigold and poor man's saffron.
How to plant marigolds
Sow pot marigolds (C. officinalis) in spring or autumn. Either sow direct in April/May or August/September into poor to moderately fertile soil that has good drainage, in sun or semi-shade. Or sow under cover (in trays, modules, or guttering, using peat-free potting compost) in March/April or October/November; sow 1-centimetre deep and 5-centimetres apart. Outside, thin to 20 to 30-centimetres apart or plant out at that distance.
Sow French (Tagetes patula) and signet (T. tenuifolia) marigolds under cover in February, March, or April or outside in May or June. Indoors, sow onto the surface of moist peat-free potting or seed compost in trays, modules, or guttering, and very lightly cover with compost. Place in a warm, sunny spot in the greenhouse or on a windowsill to stimulate germination; after germination, they can be moved to a slightly cooler spot under cover. Plant out (or sow direct) once danger of frost has passed, in well-drained, retentive soil in full sun, 30-centimetres apart.
Why you should grow marigolds with vegetables
Sow or plant marigolds in rows in between edible crops to shield them from pests, to add lines of vibrant colour, and to produce a summer-long supply of cut flowers. They are excellent companion plants because the richly scented foliage is repellent to asparagus beetle and some other unwanted visitors, yet attractive to ladybirds and several other helpful insects, which lay their eggs on the plants, and the resulting young then gobble up any aphids in the vicinity. Concurrently, marigolds lure pests (such as aphids), but this at least draws them away from your vegetables.
How to grow marigolds
- Water well until established and in hot, dry weather.
- Full sun is best for marigolds, but Calendula will grow in semi-shade.
- Soil should not to be too rich or waterlogged.
- Harvest regularly for the vase (or deadhead) to encourage more flowers.
- Feeding the plants is not necessary.
- Protect from slugs, especially when young.
- Use as companion plants in the greenhouse or vegetable patch.