They may be called wallflowers, but for early-season bloom, these biennials and perennials are belles of the ball. All have the clustered, four-petaled flowers typical of the plants in the brassica (mustard) family, but their habits and uses differ widely. In the South, usually grown as cool-season annuals.
E. cheiri. ENGLISH WALLFLOWER. Perennial in Zones US, MS; USDA 6-7, but usually grown as a biennial or an annual. From southern Europe. Branching, woody-based plants to 1212 ft. high, 1112 ft. wide, with narrow, bright green leaves and broad clusters of showy, sweet-scented flowers in spring. Blossoms are yellow, cream, orange, red, brown, or burgundy, sometimes shaded or veined with contrasting color. Sow seeds in spring for bloom the following year (some strains flower the first year if seeded early); or set out plants in fall or earliest spring. May self-sow. Regular water.
Charity series includes dwarf plants (1214 in. tall and not quite as wide) that don't need winter chill to induce flowering; set out in spring for fall bloom. Selections include soft yellow 'Charity Cream', golden yellow 'Charity Yellow', and dusty rose 'Charity Rose'.
E. hybrids. Perennials. Zones US, MS, LS, CS; USDA 6-9. Many excellent choices available. Most popular is 'Bowles Mauve', 3 ft. high and 46 ft. wide, with narrow gray-green leaves held on erect stems, each topped by a 112-ft.-long, narrow, spikelike cluster of mauve flowers. Often begins blooming in midwinter, continuing until hot weather begins in May. Often short-lived. 'Compact Bowles Mauve' is about half the size. 'Lemon Zest' grows 812 in. high and wide, with pale to lemon-yellow blooms in early spring. 'Moonlight' has bright yellow owers that open from red buds. 'Sweet Sorbet' has lilac-pink flowers on a 1418-in. plant. 'Wenlock Beauty' grows 2 ft. high and wide, with springtime flowers varying from buff to purple in a single spike. All these hybrids take moderate water.
E. kotschyanum. Short-lived perennial in Zones US, MS, and LS, often treated as an annual; USDA 6-8. Light green leaves form 6-in. mats from which rise scented, deep yellow owers on 2-in. stems in spring. Moderate water. Use in rock garden or with other small perennials between paving stones. If plants hump up, cut out central portions, transplant them, and press original plants at again. Divide clumps in fall.
E. linifolium 'Variegatum'. VARIEGATED WALLFLOWER. Zones MS, LS, CS; USDA 7-9. Shrubby growth to 2 ft. high, 23 ft. wide. Prized for its narrow, 312-in.-long leaves, which are gray-green and edged in creamy white. Mauve flowers about 12 in. across appear from spring to fall. Moderate water.
E. x marshallii (E. x allionii). SIBERIAN WALLFLOWER. Perennial, often grown as biennial or annual. Zones US, MS, LS, CS; USDA 7-9. Branching plants 1112 ft. high and somewhat wider are covered in spring with fragrant flowers in rich orange or yellow. In mild-winter climates, sow seeds in fall; elsewhere, sow in spring for well-established plants by fall. Full sun, moderate water. 'Golden Bedder' has golden yellow flowers.