Boechera, Genus, spp., Multiple species,
- Genus
- Multiple species
rockcresses
North America, most diverse in the western United States
Overview
Boechera is a genus of about 110 species of biennial and perennial herbs in the mustard family, Brassicaceae, known as rockcresses, native to North America and most diverse in the mountains and dry interior of the western United States. Plants form a basal rosette of small, often grey-green leaves and send up slender, upright stems 4 to 36 inches (10 to 90 cm) tall in spring. The four-petalled flowers are small, 0.2 to 0.5 inch (5 to 12 mm) across, in white, pink, or purple, carried in a narrow cluster at the stem tip. As the flowers fade they are followed by long, slender seed pods, called siliques, that stand erect, spread, or hang depending on species and split lengthwise to release flat seeds. Many Boechera species reproduce by apomixis, setting seed without fertilization, which has produced a large number of closely similar, hard-to-separate forms. The genus grows on rocky slopes, cliffs, gravel, sagebrush flats, and open woodland, often on dry, lean soils. Some species are larval hosts for orangetip and white butterflies. Boechera is grown mainly in rock gardens and native plant collections rather than general borders, and several species are uncommon or restricted to particular soils.
Native Range
Boechera is native to North America, with most species in the western United States and others reaching Canada, Mexico, and eastern North America. Plants grow on rocky slopes, cliffs, gravel, and dry open ground from foothills to high mountains. A few species extend into northeastern Asia.Suggested Uses
Grown in rock gardens, scree beds, troughs, and gravel plantings for its spring flowers and tolerance of lean, dry soil. Native species are used in dryland and montane restoration. Some are grown in butterfly gardens as larval host plants for orangetips.How to Identify
Appearance
Size & Dimensions
Height4" - 3'
Width/Spread4" - 1'
Bloom Information
Boechera flowers in spring and early summer, roughly March to June depending on elevation, with short clusters of small four-petalled flowers. Bloom is brief on each plant, and the long seed pods develop soon after. At high elevations flowering shifts later into summer.
Detailed Descriptions
Flower Description
white, pink, or purpleFoliage Description
grey-greenGrowing Conditions
Sun Requirements
Requires 4-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Boechera species grow in full sun to light shade on sharply drained, lean, rocky or gravelly soil and tolerate cold, wind, and drought. Most are biennial or short-lived perennial and depend on seeding to persist. Seed is sown in autumn or spring and many species need a cold period to germinate well. Plants rot in rich, wet, or poorly drained ground and grow weakly with too much feeding. They are little troubled by pests, though the foliage can carry white rust. The genus is grown in troughs, scree beds, and rock gardens that mirror its native dry, stony sites.Pruning
Boechera needs no routine pruning. Spent flowering stems are cut or left to ripen seed for resowing, since many plants are short-lived. Removing seed pods before they split limits self-seeding where it is not wanted.Container Growing
Suitable for container growing
Minimum container size: 1 gallons
