|Official Plant Name||Dianthus|
|Common Name(s)||Carnation, Pinks, Sweet William|
|Plant Type||Perennial (some annuals)|
|Native Area||Southern Europe|
|Hardiness Rating||H6 / H7|
|Foliage||Evergreen or deciduous|
|Flowers||Showy, often fragrant flowers|
|When To Sow||March, April, May, June, July, August, September, October|
|Flowering Months||May, June, July, August, September, October|
|When To Prune||October, November|
Mostly Full Sun
0.1 – 0.5M
0.1 – 0.5M
May – October
Most Fertile Soils
Dianthus, the Flower of the Gods, was as admired in Ancient Greece as it is in Modern England, and for good reasons. The double, ruffled blooms with their fringed or frilly edges are unique, and exhibit colours from palest pink to maroon-black. Reputed as ideally suited for cottage gardens, it is fair to ask whether this wonderful genus is not ideally suited for any garden.
Dianthus is quite a fascinating genus of flowering herbaceous plants: though it encompasses a fair number of species totalling about 338, much of the ‘press’ and interest surrounds only three of those species – and those three species include untold thousands of cultivars.
These three garden favourites are Dianthus caryophyllus commonly known as Carnations, Dianthus plumarius colloquially called Garden Pinks, and Dianthus barbatus, usually termed Sweet Williams.
The vast majority of cultivars of interest are evergreen perennials.
The ruffly, frilly flowers come in white, yellow, pink, red, and mauve in a remarkable range of hues from palest pastel to rich and intense. Moreover, many cultivars’ flowers are bicoloured, exhibiting feathering, edging, or flecks. They are marked by a somewhat unusual feature: the distal end of most varieties’ petals are fringed, serrated or even toothed. All Carnations have double or semi-double flowers and most Garden Pinks are double while a few are single.
Another quirky attribute Carnations and Garden Pinks, particularly the latter, have is their scent. While some are unscented, and others are moderately scented, many exude a thick, sweet fragrance redolent of cloves or cinnamon. To make it a hat-trick of unusual features, the opposite, linear (very narrow) leaves are the lexical definition of glaucous, in other words: “of a dull greyish-green or blue colour.”
Carnations are divided into Perpetual Flowering or Exhibition Carnations, Border Carnations, and Pot Carnations. The former bloom year round and are cultivated in greenhouses for exhibiting and floriculture. The latter are compact evergreens to about 25 centimetres and often have semi-double flowers.
Border Carnations are the ones with which most of us are familiar; these have a bushy, erect habit, are 50 centimetres or more, and have full double flowers. These plants are also typed by the size of their bloom and by whether there is a single flower or a spray.
One might say that Sweet Williams are the simpler, less-complicated relations of the family. It is often said that Dianthus flowers, including Carnations, are perfect for cottage gardens but that is a generalisation and, what is more, one that doesn’t hold up to inquiry.
The stately habit, complexity of the bloom, and overall refined elegance of most (though not all) Carnation varieties make them eminently suitable for manorial gardens and formal gardens, whereas it is the simple, open-faced cheeriness of Sweet Williams that makes them a natural and automatic choice for cottage gardens.
Though all Dianthus cultivars provide excellent cut flowers, Carnations are much valued by florists as they stay ‘fresher than a daisy’ in bouquets and are remarkably long-lasting in vases. Yet between Carnations, Sweet Williams, and Garden Pinks, it is the last-named that runs away with the popularity prize – Garden Pinks are British gardeners’ favourite Dianthus.
Like Carnations, Pinks too are divided into types, but they descend from different species. Besides Garden Pinks, there are Cheddar Pinks and China Pinks; the former are cultivars of Dianthus gratianopolitanus, and the latter of Dianthus chinensis. Pinks are named as such because their petals look as if they were cut by a tailor’s decorative pinking scissors which leaves a zig-zag edge.
Background and Origins
In nature Dianthus species are found clear across Europe and Asia, Northern Africa, Southern Africa, and Alaska.
Carnations and Garden Pinks, both European natives, have a distinguished history stretching back to Antiquity. In fact, Dianthus means ‘Flower of the Gods’ from the Latin ‘Deo’ meaning deity or god, and the Greek ‘antho’ meaning flower. And no wonder, for both the ancient Greeks and Romans venerated these flowers, as the formal Laurel wreath had its celebratory counterpart in the Dianthus garland.
That these plants were very popular from Hellenic Times through to Mediaeval Times is demonstrated by their appearance in friezes and bas reliefs of yore, as well as in tapestries and illuminated manuscripts of the Middle Ages.
Though these flowers were grown and bred in Roman Times, it is from the early Eighteenth Century that they have scientifically been hybridised and cultivated to develop thousands of cultivars with all manner of attractive features.
Dianthus comprise of an assortment of thousands of varieties of which 92 have been awarded the RHS’s Award of Garden Merit. It is only a matter of time before Dianthus scores a century in AGMs. Underneath we present a mere taste of what this wonderful genus has in store for gardeners.
All the Carnation and Garden Pink varieties exhibit the classic greyish-bluish-green foliage that is such a well-known attribute of these two species’ varieties. All the Carnation and Garden Pink varieties are evergreen perennials while the two Sweet William varieties are biennials.
Carnation ‘Leon Tautz’ is a tall border Carnation that can reach 75 centimetres. It has a bushy habit. It flowers only during part of the summer but no matter how brief the flowering season may be, the brilliant and stunning bloom, up to 6 centimetres in diameter, makes up for it. It has a pure white ground with vivid purplish-crimson flecks, splashes, and edging.
Carnation ‘Jean Knight’ is also a border Carnation that grows up to 50 centimetres. It has a bushy habit and blooms during the summer. The flower is seven to eight centimetres wide, and is one for the manor garden, being pure white with purplish-crimson edging that bleeds over into flecks and streaks. RHS Award of Garden Merit.
Carnation ‘Chesswood Margaret Alison’ is another tallish border Carnation that blooms during summer. Its foliage has a very bluish tone. The double flowers are large at about 7 centimetres, and are a remarkable sedate rose pink, call it ‘Slate Rose.’ It possesses a feature that Dianthus are famed for: a spicy fragrance. The flowers have a strong clove-like scent. RHS Award of Garden Merit.
Carnation ‘Mambo’ is a perpetually flowering variety that is grown year-round under glass for floriculture and exhibition. This bushy variety attains a height and spread of over one metre. The large, fully double flowers are in gorgeous tones of orangeish-yellow with the colouration being gently gradated. RHS Award of Garden Merit.
Garden Pink ‘Pixie Star’ is a dwarf variety at only about 20 centimetres with a similar spread. The foliage has an obvious bluish tinge. The blooming season starts from mid-spring and continues into summer. The small single flowers are most charming; they are candy pink with a lipstick red central ring. RHS Award of Garden Merit.
Garden Pink ‘Dainty Dame’ is also dwarf variety at only about 25 centimetres with a similar spread. The small single flowers are pure white with a very contrasty maroon central ring. These upbeat flowers have a suitably strong scent that carries a hint of spice. RHS Award of Garden Merit.
Garden Pink ‘Pinball Wizard’ is a mid-height variety that reaches around 40 centimetres. It has a bushy habit. Blooming during the summer, its double flowers are of the palest pink with flecking and feathering of a vivid pink. These comparatively refined and elegant Pinks have a mildly spicy scent.
Garden Pink ‘Rhian’s Choice’ grows to about 30 centimetres and has a bushy habit. Even by Dianthus standards, this variety’s foliage is markedly bluish-grey. The double flowers are 5 to 5-1/2 centimetres in width, and bloom during summer. They are truly eye-pulling stunners by virtue of their striking hue which varies from intense red to blood red.
Sweet William ‘Auricula-Eyed Mixed’ grows to about 60 centimetres and has an upright habit. This Dianthus’s foliage is neither greyish nor bluish but is very green. It bears merry clusters of bright pink, magenta, and purplish flowers with white or pale eyes. These blooms are quite fragrant and bloom from late spring through summer.
Sweet William ’Sooty’ or ‘Black Dianthus’ grows to about 60 centimetres and has a bushy, mounding form. It has intensely green foliage. It bears clusters of small flowers during the summer, and they are seriously (yes, again) stunning. The hue varies from maroon-black to violet-black, and the intense effect is heightened by a velvety sheen.
Habitat and Growing Conditions
Dianthus species occur in nature in extensive geographical regions and climatic zones. They are found in the heat of India and Northern Africa to the northernmost reaches of Russia. They grow in fields, woodlands, steppes, hillsides, and taiga. The various species’ hardiness varies from USDA Zone 3 to 9 (RHS Zone Sub-H7 to H3).
Nearly all the popular cultivars are hardy to RHS Zone H6. Perpetual Flowering Carnations are not hardy being suitable only to Zone H2 which is why they are grown in greenhouses. The varieties’ heat tolerance varies too. In general, various Pinks and Sweet Williams are more heat tolerant than Carnations.
Dianthus caryophyllus, Carnation, originates from the Mediterranean region including Italy and Greece.
Though Dianthus plumarius, Garden Pink, is native to Central Europe, it has colonised several regions of the United States where it is classified as an invasive species.
Dianthus barbatus, Sweet William, is from Southern Europe, growing in nature in a belt of land from Spain to Hungary and Romania. It exhibits a preference for hillsides and hilly areas.
Where to Plant Dianthus
The heights, habits, blooms, and colours of Dianthus varieties make these evergreens excellent choices for all purposes from edging a walkway to the middle rows in a mixed bed.
Dwarf Pinks which grow to 20 to 30 centimetres are ideal for rock gardens and edging. Pink ‘Pixie Star’ and Pink ‘Dainty Dame’ are excellent examples. Mat-forming Cheddar Pinks are just as excellent for such purposes. These types of dwarf evergreens are also top choices for groundcover.
Border carnations attain heights from 50 to 75 centimetres. Though in general they have a bushy habit, they can be pruned for a more columnar form. If this is done many cultivars will require staking, while some require staking anyway. They are perfect for the middle of a bed or even the rear of a narrow bed. Some varieties offer the height, habit and striking bloom to be set out on the verandah in pots. Carnation ‘Leon Tautz’ and Carnation ‘Jean Knight,’ among a few others, make fantastic specimen plants.
Midway between the two are Garden Pinks with a mounding habit and Sweet Williams. With heights falling between 30 and 60 centimetres, they are great for the front of beds and borders, and also are very well suited as pot plants and container plants. Examples include Pink ‘Pinball Wizard,’ Pink ‘Rhian’s Choice,’ and Sweet William ‘Auricula-Eyed Mixed.’
Feeding, Care and Growing Tips
Considering that the Dianthus genus is quite large and, especially, the fact that a few species have been heavily cultivated for centuries, Dianthus plants respond very well to a single set of generalised gardening tips.
Dianthus seeds can be sown outdoors directly in beds when there is no danger of frost and after the soil has warmed up a little, say late spring. The downside is that the plants will not flower that same year.
To be sure that your Dianthus flower the year you grow them, they should be started indoors, about six weeks before the last predicted frost date. You can do so in potting mix in seed trays or in small pots placed in a sunny spot or under grow lights where the temperature is between 16° and 21° centigrade.
The trade-off is that a seed tray provides an easy way to cover the germinating seeds so as to create humid conditions while small pots will afford you more flexibility as to when you transplant the young plants outdoors.
Drop a couple of seeds to a compartment or a small pot and cover with the thinnest of layers of soil. Water lightly, and close the tray’s lid or cover, or cover the tray with a humidity dome.
Keep the seeds and the seedlings consistently moist for the next several weeks.
After there is no chance of frost, the young plants can be transplanted outdoors. Before doing so, it is a good idea to harden them for about a week.
A light, clay-free, sandy, gravelly loam amended with peat moss or compost is ideal for these plants. The soil must be very well drained. Its pH should be Moderately Alkaline to Slightly Alkaline – 8.4 to 7.4.
Plants may get full sun, or morning sun and filtered or dappled afternoon sun.
When transplanting, the soil level of each plant should be the same as it was in the tray or pot. Better a little too low than a little too high.
As for the spacing, this will depend on the habit and the spread of the variety in question.
Plants should be watered at least once a week and when the soil is dry.
Dianthus cultivars require feeding but on different schedules. Almost all Pinks and many Carnations should be fed once in spring and once in late summer. On the other hand, some Carnation varieties will benefit from being fed once a month. A balanced liquid fertilizer is well suited for these plants.
Some Carnation cultivars need support as they grow. Stake them by enclosing the main stem with support canes and tying them around with twine.
All Dianthus benefit from regular deadheading as it promotes extended flowering. In addition, Garden Pinks can be cut back after flowering in mid-summer. If you do so, water the plants well and feed them with a balanced liquid fertiliser at this time. In short order they will be reinvigorated and produce fresh blooms.
In order to encourage a bushy habit or mounding in young Pinks, the leader is sometimes bent or pinched, and initial flowering is otherwise impeded until the plant develops a sufficient number of side shoots.
Disbudding is a method sometimes used in Carnations though this is done to primarily influence targeted flowers and not the plant as a whole. To maximise the size and quality of pre-selected Carnation buds for blooming, you may choose to disbud others.
Common Diseases and Problems
Dianthus, more often Carnations, can be affected by Carnation rust, bacterial wilt, and fusarium wilt. They are also subject to viral infections which cause Carnation mottle, Carnation etched ring, Carnation ring spot, and other diseases. These viral diseases require specialised treatment.
All Dianthus can be affected by aphids, which the casual gardener can treat, though with a sense of real urgency. In addition, slugs and rabbits can take a liking to them.
Dianthus can also cause a problem for one or two animals, these being your pet cats and dogs. These plants, particularly their leaves, are somewhat toxic. If chewed by cats or small dogs, nausea, diarrhoea, and vomiting may follow. Though fatal consequences are unlikely, if a pet has consumed any amount of Dianthus parts it would be best to take the pet to the vet.
Where to Buy Dianthus
Carnation, Garden Pink, and Sweet William varieties are among the easiest plants to find, with the perennial British favourite Garden Pink leading the pack. Some or other varieties are available as potted plants in virtually every nursery and garden centre. Seed packets are equally easy to find, be it at brick-and-mortar stores or online stores.
In addition, you can get new Dianthus by layering and cuttings. The somewhat more technical art of layering is usually used with Carnations while softwood cuttings work well with both Carnations and Garden Pinks.