Centranthus, Genus, spp., Multiple species,
- Genus
- Multiple species
valerian
Overview
Centranthus is a genus of about ten annual and perennial herbs in the family Caprifoliaceae, native to the Mediterranean region and adjacent parts of Europe and western Asia. The most familiar species, C. ruber, is a bushy, short-lived perennial 1-3 feet (30-90 cm) tall and wide, with fleshy, blue-green, lance-shaped leaves on branching, slightly woody-based stems. From late spring into autumn it carries dense rounded clusters of small, faintly fragrant, spurred flowers about 0.2 inch (5 mm) long, in deep reddish-pink, crimson, or white. The long bloom season and abundant seed allow the genus to colonize walls, rocky slopes, cliffs, and dry banks, often rooting in lime mortar and crevices with little soil. Plants tolerate drought, poor fertility, and alkaline conditions but are short-lived and tend to grow leggy and flop on rich or shaded sites. C. ruber has naturalized across western North America, the British Isles, and Australia, and is treated as an environmental weed in parts of California and the Pacific Northwest. Removing spent flower heads extends the display and curbs self-sowing.
Native Range
Native to the Mediterranean basin and neighboring parts of southern and western Europe and western Asia, on rocky slopes, cliffs, and old walls.Suggested Uses
Grown in dry gardens, gravel beds, rock gardens, and the tops and faces of retaining walls, where it roots in minimal soil. It suits Mediterranean and coastal plantings and combines with lavender, santolina, and ornamental grasses. Self-sown seedlings naturalize readily and may need thinning.How to Identify
Appearance
Size & Dimensions
Height1' - 3'
Width/Spread1' - 3'
Colors
Bloom Information
Detailed Descriptions
Flower Description
reddish-pink, crimson, or whiteFoliage Description
blue-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
Grows in full sun on lean, sharp-draining soil with a pH near 6.5-8.0, including chalky, rocky, and gravelly ground. Established plants are highly drought tolerant and need no supplemental water in most climates. Rich, moist, or shaded conditions produce floppy growth and shorten the plant brief life. Shearing after the first flush of bloom encourages rebloom and reduces self-seeding. Plants are short-lived but renew themselves freely from seed. No feeding is needed on average soils.Pruning
Spent flower clusters are sheared off through the season to prolong bloom and limit seedlings. Stems are cut back hard in late autumn or early spring to remove the previous year growth. Plants resprout from the woody base.Pruning Schedule
Prune: March & June–August
summerearly spring
Container Growing
Suitable for container growing
Minimum container size: 2 gallons
