For 25 years, I explored and experimented with pinks in my Zone 4 garden on Cape Breton Island. I've found that modern hybrids are hardier and more adaptable to unfavourable soil conditions. D. plumarius Ballade Strain syn. D. 'Ballad Blend' formed vigorous clumps of silvery blue foliage in my garden, where soil was heavy, on the moist side and somewhat acidic—conditions that discourage true cottage pinks.
By early summer, Ballade Strain had sent up a mass of straight stems reaching 38 centimetres, with flowers in a broad colour range—salmon, rose, red, pink and white—some banded, all with dark eyes. Very different from the petite, sprawling cottage pinks, these bold plants have a fragrance that's enticing, though not quite as heady as the cottage pinks'. Their early-summer bloom complements the blues of lavender and catmint (Nepeta spp.) and the pink hues of old roses; there's modest rebloom in late summer. The spiky blue foliage is attractive throughout fall and winter.
I grew fringed pinks (D. superbus) and 'Rainbow Loveliness' (D. allwoodii x D. superbus) in containers by our front porch to enjoy their enveloping jasmine-like aroma (both varieties are 30 to 38 centimetres tall, Zone 3). Fringed pinks have feathery flowers ranging in colour from delicate lilac to white. Hybrid strains bear flowers so deeply fringed they appear as a haze of carmine, pink, lilac or white, some banded, all intensely fragrant.
Maiden pink (D. deltoides) makes up for its lack of scent by unstinting, dazzling bloom and a tough constitution; hardy to Zone 3, it blooms even in partial shade. Growing 15 centimetres tall from a low-growing, wide mat of tiny, bright green leaves, it erupts into a sheet of small, neon pink flowers in early summer that spill over rocks and the edges of my perennial border. Recent introductions, all hardy to Zone 3, have given this old favourite a new look and ever-blooming habit: D. d. 'Arctic Fire' (20 centimetres tall) is a dainty white form with a glowing cherry red eye; 'Flashing Light' (30 centimetres tall) is bright crimson with striking bright green foliage; 'Microchips Mix' (15 to 20 centimetres tall) blooms the first year from seed and displays masses of white, pink and purple flowers, all with dark eyes. Similar pinks include the 20-centimetre-tall sand pink (D. arenarius), with fragrant, fringed white flowers, and the 30-centimetre-tall cheddar pink (D. gratianopolitanus), silvery blue foliage topped by a mass of clove-scented pink blooms, or rose in the cultivar 'Tiny Rubies' (10 centimetres tall).
Sweet William (D. barbatus) is distinguished from other pinks by its compact heads of tightly clustered, phlox-like flowers on stiff stems to 70 centimetres tall. Colours are brilliant shades of crimson, pink or white, often edged and eyed with contrasting colours; scent is light. Although it's a biennial-blooming the second year from seed—gardeners have observed that some strains grow as short-lived perennials and are more scented than others. A friend in Ontario reports that D. b. 'Newport Pink' (50 centimetres tall, Zone 3), an old strain, has survived five years in her garden and has a noticeable sweet aroma. Semi-dwarf 'Early Spring Messenger' (45 centimetres tall, Zone 3), blooming the first year from seed, is a boon where summers are short and windy.
A recent breed of hardy pink, a cross between sweet William and annual China pink (D. Ideal series), has been widely acclaimed for its early bloom (10 to 15 days earlier than annual pinks), heat tolerance and ability to survive sub-zero winter temperatures as a biennial or short-lived perennial. In the Ideal series (Zone 2) there is a wide range of colours, including splashy carmine, violet, pearl and salmon, as well as flowers with contrasting bands. Plants grow to 25 centimetres and look great at the front of a border. Shearing encourages a moderate bloom in late summer. 'Melody Pink', blooming the first year from seed, is a 2000 All-America Selection winner that grows to 45 centimetres over a mound of handsome green foliage, has spicy-scented fringed flowers of soft antique pink that bloom all summer into fall, and is resistant to heat and cold.