The Delightful Dianthus
By Rand B. Lee
The borders of spring haunt the dreams of winter, but it is not the upthrusting iris and the bouncing peony that comfort my January sleep; it is the humble cottage pink. Cottage pinks (Dianthus plumarius) have lent their charm to European cottage gardens since the Middle Ages, and they are equally at home in the herbary. They have woven themselves in and out of my borders since I was a child in Connecticut, and I have grown them here in Santa Fe since 1988; with soil preparation and some supplemental watering, they adapt easily to our dry conditions and alkaline clay soil. I love their pert five-petaled single flowers, like little eyes, which also come informally semidouble and voluptuously double. Their carefree, sturdy, drought-resistant foliage forms persistent grassy, spiky tufts or mats of gray to blue-green, decorative even when the plants are not flowering.
My favorite reason for growing cottage pinks is their delicious perfume, clovelike in some cultivars, a light fresh jasmine scent in others. The cut flowers will pour forth their fragrance indoors for as long as a week. Not all pinks are fragrant, though, and the perfume of even the most highly scented types may vary according to microclimate, season, and time of day. Their scent may be savored fresh in bouquets, tussie-mussies, and salads. (Entire flowers, when preserved in silica gel, make a wonderful topper to open-bowl clove potpourris, but they lose their fragrance on drying.)
Most cottage pinks flower in May and June, though occasional blooms open later in the season, particularly where summers are cool. Depending upon the cultivar, blooms measure from 1/2 to 1 inch wide, the petals usually toothed or fringed, sometimes smooth-edged. They are held at the end of their slim stems singly or in loose clusters. As you might expect, colors drift through the pinkish range, but gardeners have been crossing and selecting pinks for centuries, so cultivars exist in white, cream, pink, rose, red, scarlet, burgundy, magenta, lilac, pale yellow, salmon, buff, and orange, often with contrasting edges, stippling, or central “eyes”, or a contrasting color on the reverse of the petals. The flowers are edible (single pinks and Johnny-jump-ups make a lovely garnish for a spring salad) and in Elizabethan times enjoyed a reputation as a mild antidepressant.
Because most cottage pinks stand 6 to 12 inches tall, they are perfect for the front of the border, but sometimes I grow them in a bed of their own, making a little inland sea of perfumed bloom, to the drunken joy of hawk moths. They make an enchanting surround for old roses and a fine complement to the lavenders, sages, artemisias, santolinas, catmints, and other gray-leaved Mediterranean and Northern European herbs.
Authorities disagree as to the derivation of the name “pink”, but current scholarship suggests that the term comes from the German Pfingsten, or Pentecost, a Christian feast that frequently falls during the pinks’ blooming season. What is certain is that the color pink derives its name from the dianthus, not the other way around. It was Carolus Linnaeus, the great eighteenth-century Swedish botanist, who named the genus Dianthus, “divine flower”. The genus is now thought to embrace some 300 species and innumerable hybrids and selections, including cottage pinks, carnations (D. caryophyllus), sweet Williams (D. barbatus), and sweet Johns (D. superbus). Most of my favorite dianthuses are perennial, but sweet Williams are considered biennials or short-lived perennials and are often grown as annuals, and there are popular annual pinks as well. Hardiness varies according to cultivar. Most pinks are hardy to at least Zone 5, or 4b with protection: a winter cover of loosely piled evergreen boughs or a location that’s sheltered from the wind. Poorly drained soil kills pinks in the winter more often than cold does. All require dry feet.
A lasting fancy
Despite the relative obscurity of fragrant dianthuses among American home gardeners today, few groups of flowers have known as many centuries of popularity. In their excellent book Plants from the Past (Penguin Books, 1989), David Stuart and James Sutherland tell us that pinks were probably introduced to Britain in the early fourteenth century from France. In the Middle Ages, rents were paid with them, and royalty had their portraits painted with them. By the late 1500s, they were among the most popular flowering plants for containers, as they are in Europe today. The seventeenth century saw the beginnings of much deliberate dianthus breeding in England; in the next two centuries, hundreds of cultivars became commercially available, including the feathered or “starre” pinks, with very frilly petals and a pink eye; the “pheasant’s eye” pinks, with a dark central blotch and a soft band of color along the jagged petal margins; and the “laced” pinks, fully double flowers with strong color at the margin and base of each petal.
Pinks came to North America with the English colonists, and carnation breeding became the rage in the United States during the nineteenth and early twentieth centuries, but the breeding of pinks remained far more serious a passion in England than in the colonies. In Britain, regional societies of amateur and professional plant breeders vied with one another to produce pinks that conformed to show standards as stringent as those the rose societies levy on hybrid teas today. By the 1850s, the British considered pinks an old-fashioned national flower with many sentimental associations. In the Victorian language of flowers, pinks speak of pure affection.
Few really old pinks survive, but those that do are wonderfully fragrant. I have grown and loved Fair Folly, a seventeenth-century single flower colored strawberry on white; the five-petaled, fringed, green-eyed white Musgrave’s Pink, also called Charles Musgrave (1730); the eighteenth-century Inchmery, a compact, clear lavender-pink double; Dad’s Favourite (double white, edged wine), which may date from the eighteenth century; the intoxicating nineteenth-century Rose de Mai (double to semidouble fringed creamy-mauve); and perhaps the most famous of all Victorian pinks, the double white Mrs. Sinkins, introduced to commerce in 1872.
The cottage pinks most commonly offered for sale in American nurseries (such as Spring Beauty) are usually very fragrant and bloom freely. The Allwood pinks (D. ¥ allwoodii), sturdy crosses between pinks and carnations, are also floriferous and may set flowers off and on all summer if deadheaded, but they are not as highly perfumed as the antiques. Good cultivars include Doris (salmon with a red eye), Helen (deep salmon), and Desmond (dark red). Margaret Curtis, a heavily maroon-eyed white; Pink Princess, a fringed double salmon pink; and Raspberry Tart, a double maroon-eyed hot rose, are normally available only via mail order. Another beauty, which bears the odd name Aqua, sports large, powerfully scented, double pure white flowers; its petals burst from their calyx like an eighteenth-century courtesan from her bodice. Because these named cultivars do not come true from seed, they must be propagated by cuttings.
Fragrant dwarf pinks, ranging from 1/2 inch to 8 inches tall, are ideal for rockeries. My favorite species are the pale, fringed sand pinks (D. arenarius) and the compact cheddar pinks (D. gratianopolitanus), named for Cheddar Gorge, their original home in Somerset, England. The wild superb pink or sweet John (D. superbus) has flowers so deeply fringed that they have practically no center and a perfume so pervasive that it wafts through the garden on the slightest breeze. A vase of them by the bed can actually disturb the sleep. A hybrid superbus strain, Rainbow Loveliness, bears flowers in a range of soft pastels, larger and longer blooming but no less fragrant than those of the species. Though hardy in the wild to Scandinavia, the superbuses are not long-lived in the garden—I have never been able to keep any of these more than three years—but they come true from seed, which they set in copious quantities. By contrast, the brilliantly colored annual China pinks (D. chinensis and hybrids), which are commonly sold in garden centers as bedding plants, are scentless, or virtually so, despite some catalog claims.
Carnations (D. caryophyllus) are the best-known members of the pinks, but many people are surprised to learn that they were originally cultivated for their strong clove scent. An old name for the carnation is clove gillyflower, “gillyflower” being a corruption of the French gilofre, “clove spice”, itself a corruption of the Latin caryophyllus, “clove tree”. Most modern carnations have had the scent bred out of them, but not all. The hardy border carnations produce smaller flowers than the florist’s carnation, which though derived from the same species belongs to a different class entirely, the generally tender perpetual-flowering carnations; many hardy border carnation cultivars possess a strong fragrance. Named cultivars are difficult to find in the United States; fortunately, seed strains are readily available. Among those notable for their scent are the Grenadin series, particularly the white and reds; the compact Dwarf Fragrance strain; and a trailing form sold as Swiss Balcony Trailers or Swiss Hanging Basket Carnations. This last produces long-blooming plants with rather sparse, drooping foliage and small, fully double, much-fringed, extremely fragrant flowers in shades of red or pink.
I start my dianthus seeds indoors in early February, scattering them thinly on the surface of a sterile, well-drained commercial potting medium, watering just to moisten, then covering with plastic and placing over bottom heat. Thus treated, the seedlings spring up within three days to two weeks, whereupon I remove them from the heat. Since dianthuses require bright, cool conditions for best growth, I place my flats on my sunniest windowsill or 2 inches below fluorescent lights in a well-ventilated 50°F room. I keep an eye out for damping-off, a soil-borne fungus disease that attacks seedlings, but it is usually a problem only in soils that are too moisture-retentive. Within three to four months from sowing, the young plants will be ready for transplanting into the garden or pots.
Pinks may also be propagated from slips or cuttings; this is the only way to increase your store of named cultivars. In mid- to late summer, select stocky, thick-leaved, nonflowering shoots from your healthiest plants. Count down three or four pairs of leaves from the tip of the shoot and make your cutting with a very sharp knife or razor blade 1/4 to 1/3 inch below the “heel”, the swollen joint where the leaf pair joins the stem. Put the cutting immediately into a plastic bag with a wet paper towel or a teaspoon of water so that it does not dry out at any stage, and keep it out of the sun.
After collecting as many shoots as you want, strip the lower two pairs of leaves off each one. Dip each cutting in rooting hormone and stick it in a flat or other container filled with sand, vermiculite, or a mix of half perlite and half vermiculite that is just moist. Work carefully; do not bury the heel or rub off the hormone powder. Space the cuttings about 1 inch apart in the rooting container. When it is full, cover it with plastic or glass and place it in a well-lit spot shaded from direct sun or a few inches under cool fluorescent lights and atop heating cables. Remove the covering after two or three days, but do not let the rooting mix dry out at any time. Periodic misting will help. In about three weeks or so, your cuttings should begin to turn their tips slightly toward the light and start to grow, a sign that rooting has begun. I usually root more than I need so that I can dig one up from time to time to check on how well it is rooting. When the root ball is the diameter of a quarter, which may take several months, transplant each cutting into a 4-inch pot filled with well-drained soil and transfer it to a cold frame, greenhouse, or light unit until spring.
Pinks require full sun (part afternoon shade in very hot, bright, dry climates) and only moderate water, and they will do best in well-drained alkaline soil on a spot free from standing water year round. Providing these conditions is easy if you are growing dianthuses in pots or window boxes; any well-drained commercial potting mix will do with a bit of lime mixed in. I border my perennial beds with carnations and pinks, so I must deal with dense, heavy southwestern clay, which possesses alkalinity aplenty but virtually no organic matter or drainage.
A month to two weeks before my dianthuses are due to go in the ground, I dig a foot-wide trench with my garden fork where the plants are to grow, removing the clay to a depth of 12 to 18 inches. I loosen the clay at the bottom of the trench, then sprinkle in a light application of dried kelp meal (for micronutrients) and nitrogen-rich cottonseed meal. (If your garden soil is acidic, substitute bone meal for the cottonseed meal and dust the trench with agricultural lime.) Then I mix the soil removed from the trench with finely sifted, well-aged compost, adding coarse sand or gravel for drainage, so that the result is about one-third native soil, one-third sand or gravel, and one-third compost. I backfill the trench with the amended soil, rake the bed smooth, and let it rest until my plants are ready for the outside world.
In my Zone 6a mountain garden, I plant out dianthuses anytime between April 15 and September 15, taking care to harden them off first, then setting them no deeper in the ground than they were in their pots. I water in the starts with a solution of 1 tablespoon each liquid seaweed and fish emulsion dissolved in 1 gallon of water, watching to make sure that the liquid sinks quickly into the soil (indicating good drainage) instead of puddling on the surface (indicating bad drainage and the need for lots more sand or gravel and possible resiting). Then, because I am a fanatic and because dianthuses respond well to foliar feeding, I spray their leaves with the same kelp-and-fish solution until it drips off. That seems to minimize transplant shock.
In my dry climate, I must water with a soaker hose to avoid losing water to evaporation. I lay the soaker hose on the ground around the plants. I’ve learned by experience that burying it the recommended 2 to 6 inches underground, which might be fine in sandy soils, increases the danger here that too much water will collect around the plants’ roots; if that happens and the plants begin to suffer, there is nothing for it but to dig them up and raise their beds or move them to a better-drained location. If you water by hand, mulch the plants with small stones or gravel, or make a little rim of soil around each plant to keep the moisture from running off before it has a chance to sink in. Other than a drape of evergreen boughs, do not mulch dianthuses in winter. Crown rot organisms love moist mulch, and crown rot is the main reason why my beloved Musgrave’s Pink died before I had the chance to savor a single green-eyed blossom. I have never had any other disease attack my plants, and insects have not been a problem. In wetter climates, slugs will snack on cottage pinks; beer traps or hand-picking will help control them.
Aimers Quality Seeds, 81 Temperance St., Aurora, ON L4G 2R1, Canada. Catalog $4.
Allwood Brothers, Mill Nursery, Hassocks, West Sussex BN6 9NB, England. Catalog free. Seeds; U.S. credit cards accepted.
Canyon Creek Nursery, 3527 Dry Creek Road, Oroville CA 95965. Catalog $2. Plants.
Chiltern Seeds, Bortree Stile, Ulverston, Cumbria LA12 7PB, England. Catalog $3; U.S. credit cards accepted.
Logee’s Greenhouses, 141 North St., Danielson CT 06239. Catalog $3 (refundable). Plants.
Surry Gardens, PO Box 145, Surry ME 04684. List free. Plants.
The Fragrant Path, PO Box 328, Fort Calhoun NE 68023. Catalog $1. Seeds.
Thompson & Morgan, PO Box 1308, Jackson NJ 08527. Catalog free. Seeds.
Rand B. Lee is founder and president of the American Dianthus Society and coeditor of the magazine The American Cottage Gardener. He lives in Santa Fe, New Mexico, with his blind husky, Moon Pie.
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