Xylorhiza, Genus, tortifolia, Species,
- Genus & species
Mojave Woodyaster
Mojave and Sonoran deserts, southwestern United States
Overview
Xylorhiza tortifolia is a rounded perennial subshrub reaching 1-2.5 feet (30-75 cm) tall and about as wide, with a woody base and many erect, leafy stems. The leaves are narrow, 1-3 inches (2.5-8 cm) long, gray-green, often twisted, with wavy spine-tipped margins. From late winter through spring it carries solitary daisy-like flower heads 1.5-2.5 inches (4-6 cm) across on long stalks, each with 40 or more pale lavender to violet ray florets surrounding a yellow disk. The seeds are small dry achenes topped with a tuft of bristles for wind dispersal. X. tortifolia grows on rocky slopes, desert washes, and roadside banks in the Mojave and northern Sonoran deserts. It can take up selenium from desert soils, and foliage grown on seleniferous ground can be toxic to grazing livestock. Plants are deeply rooted, drought-adapted, and resprout from the woody base after the dry season. Growth is sparse in shade and on heavy, wet soils.
Native Range
Xylorhiza tortifolia is native to the southwestern United States, mainly the Mojave Desert and northern Sonoran Desert of California, Nevada, Arizona, and Utah. It grows on rocky slopes, canyon walls, desert washes, and roadcuts at low to middle elevations.Suggested Uses
Xylorhiza tortifolia is grown in desert, rock, and low-water gardens, spaced 18-24 inches (45-60 cm) apart. Its large lavender daisies add early-season color to dryland plantings. It draws native bees and other pollinators in late winter and spring.How to Identify
Appearance
Size & Dimensions
Height1' - 2'6"
Width/Spread1' - 2'6"
Bloom Information
Detailed Descriptions
Flower Description
Lavender with yellow centerFoliage Description
Gray-greenGrowing Conditions
Sun Requirements
Requires 6-12 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
Xylorhiza tortifolia grows in full sun in dry, fast-draining sandy, gravelly, or rocky soil with a pH from 6.5 to 8.0. It is deeply drought-adapted and needs little to no supplemental water once established. Plants resprout from the woody base after the dry season and are sensitive to overwatering and heavy clay. In zones 8 to 10 it grows outdoors year-round in desert and low-water gardens. Foliage grown on selenium-rich soils can be toxic to grazing livestock. Growth thins in shade and in soils that hold moisture.Pruning
Light shearing after the main spring bloom removes spent flower stalks and keeps the subshrub rounded. Cutting back leggy stems in late winter encourages denser growth. Hard pruning into bare old wood may not regrow.Pruning Schedule
Prune: May
late spring
Container Growing
Suitable for container growing
Minimum container size: 3 gallons
