Primroses form tufts of foliage, above which rise flowering stems carrying showy, circular, five-petaled blossoms in late winter and spring. The blooms may come on individual stems, in clusters at stem ends, or in tiered clusters like candelabra up the stem.
Most primroses are native to the Himalayas and cool regions of southeast Asia and Europe, so they thrive with a combina- tion of moist, rich soil and cool, humid air. Few areas in the South supply these conditions. While most primroses listed below will grow as perennials in the zones indicated, many of them are best treated as cool-weather annuals.
P. auricula. AURICULA. Zones US, MS, LS; USDA 6-8. To 68 in. high, with broad, leathery gray-green leaves to 5 in. long forming rosettes to 1 ft. wide. Blooms in early spring, bearing clusters of fragrant, yellow- or white-eyed flowers in colors including orange, pink, rose, red, purple, blue, white, cream, and brownish. Usually grown in pots.
P. elatior. OXLIP. Zones US, MS, LS; USDA 6-8. Leaves to 8 in. long, hairy on undersides, form foliage clumps to 10 in. wide. Sulfur-yellow spring blossoms appear in many-flowered clusters on 8- to 12-in. stems.
P. japonica. JAPANESE PRIMROSE. Zones US, MS, LS; USDA 6-8. From Japan. Stout, 2-ft. stems bear whorls of up to five yellow-eyed purple flowers. Leaves are 69 in. long, 3 in. wide; clumps grow about 1 ft. wide. Among the best selections are 'Alba' (white), 'Apple Blossom' (pale pink with a red eye), 'Miller's Crimson' (red), and 'Postford White' (white with red eye). Ample water; will even grow in shallow water.
P. juliae hybrids. JULIANA PRIMROSE. Zones US, MS, LS; USDA 6-8. Rounded, scallop-edged, bright green leaves to 2 in. long form a 10-in.-wide rosette. In early spring, flowers are borne singly or in clusters on 3- to 4-in. stalks; colors include white, blue, yellow, orange, red, pink, purple. Excellent for edging, woodland, rock gardens. Best with regular water but will accept drier soil than most primroses.
P. malacoides. FAIRY PRIMROSE, BABY PRIMROSE. Usually grown as annual (indoor potted plant). Foot-wide evergreen rosettes of soft, pale green, long-stalked leaves, oval with lobed and cut edges, 13 in. long. White, pink, rose, red, or lavender blooms in lacy whorls along upright, 8- to 15-in. stems. Good under high-branching trees, with spring bulbs, in flower beds. Tolerates light frost. Available from greenhouses in late winter and early spring.
P. obconica. Usually grown as annual (indoor potted plant). White, pink, salmon, lavender, or reddish purple flowers, 12 in. wide, in broad clusters on 1-ft. stems. Plants reach 1 ft. wide. Evergreen, roundish, hairy leaves on long stems. Hairs on stems (except those of Freedom strain) may irritate skin. Available from greenhouses in late winter and early spring.
P. x polyantha. POLYANTHUS PRIMROSE. Zones US, MS; USDA 6-7, usually grown as an annual. Often called English primrose. Foliage clumps to 9 in. wide; the 8-in.-long, green leaves resemble romaine lettuce. Bloom season runs from winter to early or midspring; 1- to 2-in.-wide flowers in many brilliant colors come in large, full clusters on 1-ft.-tall stems. Miniature Polyanthus types have smaller flowers on shorter stalks. Choose from the many large-flowered strains, like Crescendo and Pacific Giant, or look for novelties such as the Gold Lace group, with gold-edged, yellow-centered, deep mahogany petals; 'Zebra Blue' with lovely blue-and-white striped petals; 'Penumbra', similar, with silver-edged petals; and 'Guinevere', with bronzy foliage and soft pink, yellow-eyed blooms. All good for massing, bulb companions, or pots.
P. sieboldii. ASIATIC PRIMROSE. Zones US, MS, LS; USDA 6-8. Grows 1 ft. high and wide, with oval, light green, deeply lobed and toothed leaves. Produces white, pink, or purple, white-eyed flowers, each 1 in. wide, in clusters of 2 to 15 in early spring. Many named selections in deep or light colors; flowers of some have fringed petals. Leaves of all types usually die back shortly after flowering.
P. veris. COWSLIP. Zones US, MS, LS; USDA 6-8. Leaves to 8 in. long, slightly hairy on undersides, form a clump to 10 in. wide. Large clusters of fragrant, bright yellow (sometimes red or apricot) flowers are held on 8- to 12-in. stems. Blossoms of 'Sunset Shades' feature yellow throats and petals in a blend of orange to deep red.
P. vulgaris. ENGLISH PRIMROSE, PRIMROSE. Zones US, MS, LS; USDA 6-8. Tufts of leaves much like those of P. polyantha; clumps grow about 1 ft. wide. Spring flowers are typically borne singly on 8-in. stalks, though some garden strains have two or three blossoms per stalk; colors include white, yellow, red, blue, bronze, brown, and wine. Single series like Danova, sweet-scented Primera, and large-flowered Supreme are ubiquitous, but doubles and rose-flowered series like Belarina and Rosanna are gaining popularity. Hybrids called the Kennedy Irish Primroses include 'Drumcliff', with flowers that emerge light lavender changing to white with a yellow eye, and 'Innisfree' with yellow-eyed red flowers atop bronzy purple foliage. Use as edging, in woodland garden.