This genus swallowed up Cheiranthus, which included the old-fashioned biennial bedding-plant wallflowers and several choice perennials. All have the typical clustered four-petaled flowers that give the crucifers their name, but their habits and uses differ widely.
Perennial in Zones 4–6, 14–17, 22, 23, but usually grown as a biennial or annual. From southern Europe. Best in cool, moist regions. Branching, woody-based plants 1–2 1/2 ft. tall, 1–1 1/2 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. Main bloom period falls between that of primroses and summer bedding plants.
Under ideal conditions in coastal Pacific Northwest may bloom year-round. 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.Erysimum insulare suffrutescens
Native to central and Southern California coasts. Woody-based growth to 6–24 in. high, 4–12 in. wide, with narrow leaves and fragrant orange-yellow flowers in spring. Requires little water.
This is the most popular of the Erysimum hybrids, growing to 3 ft. tall and 4–6 ft. wide, with narrow gray-green leaves held on erect stems, each topped by a 1 1/2 -ft.-long, narrow, spikelike cluster of mauve flowers. Best in areas with cool summers and mild winters, where bloom is practically continual; elsewhere plants bloom from winter through spring. Often short-lived.
Native to the temperate Pacific coastal regions of North and South America, these clumping evergreen a...
The hardier species are native to cold-winter regions of Europe and Asia, where they bloom with winter...
Hardy, symmetrical, easy-to-grow plants with evergreen fronds, except in the case of P. braunii