Delphinium nudicaule
red larkspur
Overview
Delphinium nudicaule is a perennial wildflower in the buttercup family (Ranunculaceae), growing from a cluster of fleshy tuberous roots to 8-24 inches (20-60 cm) tall. Most of its rounded, palmately lobed leaves are basal and long-stalked, and they often wither by flowering time. The slender, nearly leafless flowering stalk carries an open spike of tubular red to orange-red flowers, each 0.6-1 inch (15-25 mm) long with a prominent backward-pointing spur and small inner petals. The red coloring and tubular shape draw hummingbirds, the main pollinators. Flowering occurs in spring, after which the plant sets dry follicles of seed and dies back to its roots, going summer-dormant. D. nudicaule grows on rocky slopes, road banks, and partly shaded canyon walls in California and southwestern Oregon, often in soils that dry out in summer. All parts of the plant contain diterpenoid alkaloids and are toxic to people and livestock if eaten. Its summer dormancy leaves a gap in the garden, and it can be short-lived in heavy or wet soils.
Native Range
Native to California and southwestern Oregon, where it grows on rocky slopes, road cuts, streambanks, and shaded canyon walls in the Coast Ranges, Sierra Nevada foothills, and Klamath region, generally below 8,500 feet (2,600 m).Suggested Uses
Grown in native, woodland-edge, and rock gardens in the West, where its red flowers add spring color on dry, rocky slopes. It is planted to draw hummingbirds in spring. Its summer dormancy suits it to plantings combined with later-emerging perennials.How to Identify
Appearance
Size & Dimensions
Height8" - 2'
Width/Spread6" - 1'
Bloom Information
Flowers appear in spring, mainly March through June depending on elevation and latitude. The loose spike opens from the bottom upward over two to four weeks. After bloom the foliage yellows and the plant retreats to its roots for the dry summer.
Detailed Descriptions
Flower Description
red to orange-redFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 3-6 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
Delphinium nudicaule grows in part shade to part sun on sharply drained rocky or gravelly soils with a pH near 6.0 to 7.5. It needs moisture through spring growth and bloom, then a dry rest as it goes dormant in summer; wet summer soil rots the roots. It is hardy in roughly USDA zones 7 to 9 and withstands light frost. The plant is slow to establish from seed and resents transplanting once rooted. All parts contain toxic alkaloids, so it is kept away from grazing animals and out of vegetable beds. Established plants need little care beyond a summer dry period.Pruning
Spent flower stalks can be cut after bloom, leaving seed heads if self-sowing is wanted. The dying foliage is left to feed the roots before it is removed once fully yellow. No other pruning is needed.Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons