Horticulture Magazine

Marigolds Plant Care & Growing Tips

yellow blooming marigolds in a field

Marigolds Overview

Official Plant NameMarigold
Common Name(s)Tagetes
Plant TypeAnnual Flower
Native AreaMexico & Guatemala
Hardiness RatingH2
ToxicitySome cause skin allergies on contact
FoliageDeciduous
FlowersDaisy-like single or double flowers
When To Sow (Indoors)March, April
Plant OutMay, June
Flowering MonthsJune, July, August, September
Sunlight

Preferred
Full Sun

Exposure
Exposed or Sheltered

Size

Height
0.1 – 0.5M

Spread
0.1 – 0.5M

Bloom Time
June – September

Soil

Preferred
Clay, loam, sand

Moisture
Moist but well drained

pH
Any

Marigolds are among the most readily-identifiable of flowers the world over – their rounded, densely-packed, flowerheads in sunny hues from light yellow through gold to red stand out in any garden.

Marigolds are valued not only in gardens but for religious ceremonies in India and Latin America. Nearer home, these easy-care plants are more appreciated for their wonderfully long flowering seasons.

There’s nothing quite like a Marigold. Very full and often a little dome-shaped, its multi-petalled double blooms come in warm tones from lemon yellow through gold to near red. The flowers are good sized at 5 to 12 centimetres wide, and are also remarkably symmetrical and proportional.

They have a very long flowering season; some varieties get started in mid-spring and continue into autumn. Those are probably reasons enough that Marigolds are a summer garden staple in so many countries stretching from the Americas through Europe to Australia. Another reason is that these herbaceous annuals are easy-grow low-care plants.

The Marigolds that most persons in most regions know and are accustomed to are members of the Tagetes genus. Another ‘Marigold,’ usually differentiated by referring to it as ‘Pot Marigold,’ is better known in the British Isles than elsewhere. This ‘other Marigold’ is from a separate genus, Calendula. Some of its varieties bear a superficial resemblance to Tagetes Marigolds, hence the confusing naming.

a sea of green foliage with yellow and orange marigold flowers
A Sea of Green and Globules of Sunburst

Genus Tagetes includes within it about 50 species and several hundred hybrids and cultivars. Among the 50 species, the two key ones, from a flora-centric viewpoint, are Tagetes erecta and Tagetes patula.

Tagetes erecta is informally called ‘African Marigold’ and Tagetes patula, ‘French Marigold’. This nomenclature may justifiably cause Latin Americans to feel aggrieved because both species originate from Central and South America! At least Tagetes lucida is known as ‘Mexican Marigold’ but that’s scant consolation.

Other species include Tagetes lucida and Tagetes tenuifolia; their flowers are also used, though less frequently so, for ornamental and celebratory purposes but they are much valued for their medicinal properties. The increasingly popular hybrid T. erecta x T. patula and the F1 Zenith hybrid deserve a mention as these combine the best qualities of either genus in particularly robust and trouble-free (relatively) new ‘semi-species.’

All of these Tagetes species fall under Family Asteraceae. As such, one must bear in mind that technically Marigold ‘flowers’ are, in fact, composite flowers, flowerheads, or capitula, and the ‘petals’ are actually ray florets.

Tagetes leaves come in varying shades of green depending on the variety. What they have in common is that they are heavily lobed or divided, and are pinnate. They occur in an alternate or opposite arrangement. The foliage exudes a strong aroma and it can cause skin rashes and allergies in sensitive persons.

Oddly enough, the flowers of all species are used to cure scabies and other skin conditions. They have been used for curative purposes for centuries and over the past few decades it has been scientifically established that they contain medicinal and beneficial compounds.

single red Tagetes erecta flower
A Lovely Single Specimen of an African Marigold

Background and Origins

In adopting the Marigold as a flower to be valued for its medicinal qualities, used as a culinary ingredient, and cherished for religious rituals, the ‘Indian Indians’ of the Indian subcontinent have followed in the path of Amerindians of Central America. 

Many centuries ago, well before the conquistadors had made landfall, Aztecs made regular use of Tagetes lucida as a foodstuff and also as a curative herb to treat diverse ailments. It is said that Montezuma cultivated these plants in his garden.

Tagetes erecta was also used for miscellaneous medical conditions and continues to be so used to this day in both Central America, and in India and neighbouring countries. However, this species was mainly used by the Aztecs in religious rituals for the dead and the departed.

Tagetes species originated from the regions of Mexico and Central America and naturalised in South America and the region of the American South-West, where they are now considered to be native.  

Courtesy of the Spanish conquistadors plants were sent to Europe as early as the Sixteenth Century. Carl Linnaeus described the genus in his Species Plantarum in the 1750s. At about the same time French floriculturists started to develop Tagetes patula in a big way; as a result, colloquially this species came to be called ‘French Marigold.’

a roadside stall in India with tagetes in a large basket
Marigolds are Commonly Seen at Roadside Stalls near Temples in India

Varieties

Tagetes erecta or ‘African Marigold’ varieties vary widely in height, ranging from 30 to 120 centimetres with a majority hovering around 90 centimetres. Some varieties have an upright habit while others have a bushy one, and their spread ranges from 30 to 60 centimetres. Flowerheads are up to 12 centimetres across, are mostly double but sometimes single, are quite dense, and resemble a pompom. The colour varies from pale yellow to orange.

T. erecta ‘Big Top Yellow’ rises to about 90 centimetres and has a bushy habit. It produces flowers from early summer into autumn. The densely-packed rounded flowerheads are about 8 centimetres wide and are an intense sunny hue of yellow. 

T. erecta Inca I Orange is one of the less common types that is both a dwarf to about only 30 centimetres and with an upright habit. This productive variety bears blooms from summer until late autumn. The pompom-like flowerheads are 8 to 9 centimetres across and are that classic golden-orange hue that is usually associated with Marigolds.

T. erecta ‘Kushi Mix’ has dimensions plumb in between the above two varieties with a height of 75 centimetres and spread of about 60. It is a new variety from India that is considered to be robust and weather-resistant – the flowerhead will tolerate damp and wet. This variety is a mix, and colours include different shades of yellow, gold, and orange. 

a large round yellow Marigold flower in focus
The Dense Pompom-like Brilliant Yellow Flowerhead of ‘Big Top Yellow’

Tagetes patula or ‘French Marigold’ varieties usually range from 20 to 30 centimetres with a spread of 15 to 25 centimetres. They have a bushy habit. Their smaller flowerheads are about 5 centimetres across, and occur in single form as well as double. Their colours range from a deep yellow to red.

T. patula ‘Alumia Vanilla Cream’ grows to 30 centimetres with a proportional, bushy habit. Its long flowering season extends from late spring well into autumn. The semi-double flowerheads are quite big for T. patula at 6 to 7 centimetres. In an amusing coincidence this ‘French Marigold’ is in the exact hue of French Vanilla ice-cream!

T. patula ‘Strawberry Blonde’ attains a height of only about 25 centimetres and has a bushy habit. It too has a very long flowering season stretching from mid spring deep into autumn. The flowers are only 5 centimetres across but they make up for it by their colours. Some flowers open in shades of deep pink and rose and mature to yellow; others retain salmon, rose, and russet hues.

T. patula ‘Safari Scarlet’ is another dwarf variety that reaches about 25 centimetres; it has a finely-branched and bushy habit. It produces blooms from mid spring to late autumn, and they are gorgeous. The double but not dense flowers are a rich mahogany orange to scarlet with golden-yellow edging on each petal. R.H.S. Award of Garden Merit.

Zenith F1 series varieties combine the compact size and bushy habit of Tagetes patula with the larger flowerheads of Tagetes erecta. They have a height and spread of 30 to 35 centimetres, often with a mounded form. The flowerhead is 7 to 8 centimetres across. Because these hybrids cannot set seed they continue producing flowers well into autumn. Even by Marigold’s lofty standards this series’ cultivars are floriferous. Marigold ‘Zenith Deep Orange’ features large double flowerheads of a perfect, rich orange. Marigold ‘Zenith Red’ features large, very dense, flowerheads in vermilion to red.

red safari scarlet marigold flowers
T. patula ‘Safari Scarlet’ is of an Arresting Hue and can be Near-Red

Habitat and Growing Conditions

In their native regions of Mexico, Central America, and South America, Tagetes species grow in and near forests and thickets, near villages, in fields, hillsides, shrubland,  – in short, wherever it is at all possible for vegetation to grow.

These are tough plants and adapt themselves to a variety of soils and climatic conditions, a fact demonstrated by Tagetes species easily naturalising themselves to numerous regions where they have been introduced, including large swaths of Asia and Africa. 

The only habitats they cannot conquer are cold and frigid regions as they are frost-tender with a Hardiness of only H2.

‘African Marigolds’ can and do grow in hotter and dryer locales than their ‘French’ relatives.

A Planting of Golden Marigolds Decorates a Busy Road in Mexico City
A Planting of Golden Marigolds Decorates a Busy Road in Mexico City

Where to Plant Tagetes Marigolds

Marigolds, especially taller ‘African Marigold’ varieties, can be truly stunning in mass plantings – innumerable globules of varying tints of gold in the sunlight is a sight to behold. Such a mass planting can be of a single variety for an intense and overwhelming effect, or it can feature many different types and colours to introduce variation and to show off the heights and forms of the plants, and the hues of their respective flowers.

We do not believe that conventional Marigold varieties make great potted plants or specimen plants. On the other hand, the F1 hybrids of the Zenith series are as if made to order for growing in pots and containers. Zenith series Marigolds may actually present themselves better in small containers, and even as accent plants.

We feel that both T. erecta and T. patula varieties are ideally suited for, besides mass plantings, courtyard gardens and formal gardens. If a plant and a flower could ever be called ‘architectural,’ the African Marigold is it.

As a general rule, ‘French Marigold’ varieties are great choices for edging and for the front of mixed beds while T. erecta varieties are equally good choices for the middle and rear of mixed beds. Marigold varieties’ hues in the yellow-to-red spectrum can be mixed with plants bearing flowers in similarly warm hues, or matched with complementary blues and purples for a visually striking bed.

Marigolds, particularly ‘French Marigolds’, are very frequently deployed as companion plants for vegetables. Not only do they provide a pleasing visual focus, such ‘deployment’ of these ‘weaponised’ members of the Plant Kingdom is beneficial for almost all vegetables except legumes as Marigold roots repel soil nematodes, the plants deter aphids, and the flowers lure slugs and snails away from veggies!

a mix of pansies, petunias, violas, marigolds and other flowers
Match Marigolds with Purple Flowers for a Thrilling Complementary Colour Combo

Feeding, Care and Growing Tips

How you set about planting Marigold seeds is very much dependent on two factors: your geographical region and the Marigold type, viz. T. erecta versus T. patula – ‘African Marigold’ versus ‘French Marigold.’ This is because T. patula cultivars come into flower within only 60 days while T. erecta cultivars need at least 75 days and even up to 100 to bloom. In conjunction with that, consider your region’s growing season – in the north and Midlands it will be shorter than in the south-west of the country. 

In most regions you should be able to plant T. patula cultivar seeds directly outdoors and enjoy a long blooming season. With T. erecta cultivars, your region’s growing season will dictate whether you can plant seeds outdoors or whether you should start them indoors. So, for example, in Leeds, with your average growing season of 163 days, if you sow seeds directly outdoors (not that we recommend it) you can enjoy T. patula Marigolds for three months but it would be a waste to sow T. erecta directly outdoors.

If you start Marigolds indoors, do so four to six weeks, adjusting for the variety, before the last predicted frost date for your region. Use a sterile potting mix in small biodegradeable pots for easy transplanting and to build in some flexibility. Put seeds three or four to a pot, patting them into the soil. Cover with a fine layer of soil and lightly dab it down. Water well. 

Alternatively, you can simply buy plug plants or young plants in pots to mature indoors.

Marigold seeds do not need light to germinate but they do need the right temperature, and humidity is preferable. Soil temperature should hover around 21° centigrade for the seeds to germinate. You can introduce humidity by covering (but not sealing) the pots with cling film or shrink wrap. Remove it as soon as the seedlings sprout, which should be in three or four days.

an orange and yellow french marigold flower in focus
Some ‘French Marigold’ Varieties Have Bi-Coloured Flowers

Keep watering the sprouting plants and thin them as necessary. 

Transplant outdoors after there is no danger of frost. Space the young plants per the spread and needs of the variety in question. As a rule of thumb, ‘African Marigold’ varieties should be spaced at about 50 to 60 centimetres and ‘French Marigold’ varieties at about 25 to 45 centimetres.

Regardless of whether you sow Marigold seeds directly outdoors or transplant them later, in the United Kingdom they should be sited in full sun. In the sunnier, warmer regions of the country they can be sited where they get filtered or dappled sunlight in the afternoon. The soil should be a light and moderately fertile loam. Good drainage is preferable and is a must if the soil is at all clayey or otherwise heavy.

For such popular and pretty plants Marigolds are amazingly low care. They are unfussy about the type of soil and also the pH. That said, the plants will perform best if the soil is amended with some organic compost and the pH is between 6.0 and 7.5.  

Water them about weekly but more often in dry and hot weather. Though you do not need to water at soil level, do not allow water to fall on the flowerheads. As densely packed as they are, they are prone to rotting if they become wet.

Marigolds do not require fertilizing but a light feeding of slow-release 0-10-10 fertiliser just before the start of the flowering season will give the blooms to come that added boost. Do not feed Marigolds with a balanced fertilizer.

Pruning Tagetes Marigolds

Some Tagetes erecta varieties have a habit that can only be described as a ‘lanky habit’ (though a few others actually have a bushy habit). They shoot up, produce a flower, and only then start to branch. To foster bushy growth, after the plant is about six weeks old, pinch out the leader just above the topmost leaf node. Tagetes patula varieties are compact and bushy to begin with, and need not (or should not) be pinched.

Regardless of whether or not you pinch a Tagetes erecta variety, keep an eye on it. If it gets droopy, which can happen at any point in the plant’s life, you should stake it.

Farmers Harvesting Marigolds from a Field in Puebla, Mexico 

Common Diseases and Problems

farmers collecting tagetes on a cloudy day
‘French Marigold’ varieties are admirably resistant to pests and diseases.

‘African Marigold’ varieties can be attacked by glasshouse red spider mite and may ‘catch’ powdery mildew. 

Glasshouse red spider mite must be taken care of with despatch. The good news is that you have a choice of treatments. Newer biological controls include predatory mites and a predatory midge. More traditional organic chemical options include sprays like Neudorff Bug Free and oils like Vitax Plant Guard. Biological controls and traditional chemical treatments should not be used in conjunction with one another. 

It is not only humans who like the piquant taste of Marigolds, slugs and snails enjoy eating them too. At least these pests are not difficult to control.

Where to Buy Tagetes Marigolds

Marigolds of many varieties are among the most easily-found plants at nurseries and garden centres. They are commonly sold as plug plants in trays and young plants in small pots. While brick-and-mortar outlets also sell Marigold seeds, the widest variety of seeds are found online at specialist merchants.

a hanging floral toran decoration of marigolds
A Hanging Floral Decoration – ’Toran’ – of Marigolds

Though Marigolds are not invasive, many varieties are reliable self-seeders so you may choose not to deadhead religiously and let a fair number of blooms on some plants go to seed. Then, the following year you will automatically get Marigolds sprouting up in late spring.

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