Overview
Bupleurum is a large genus of around 190 species in the carrot family (Apiaceae), spread across Europe, Asia, North Africa, and North America, with the greatest diversity in the Mediterranean and Asia. The genus is varied in form, including slender annuals such as B. rotundifolium, herbaceous perennials, and the evergreen shrub B. fruticosum, ranging from 8 in to 6 ft (20 cm to 1.8 m) tall. Atypically for the family, many species have simple, undivided leaves, sometimes blue-green and perfoliate, with the stem appearing to pass through the leaf. The small yellow to yellow-green flowers are held in compound umbels, often ringed by leafy bracts, from late spring through summer and into autumn depending on the species. Across the genus plants grow in grassland, rocky slopes, scrub, and coastal sites, generally on well-drained soils in full sun. Most tolerate poor, dry, and alkaline ground, while a few demand more moisture. Some annual species self-seed freely and can become weedy, and several are used in herbal medicine and as long-lasting cut foliage.
Native Range
Bupleurum ranges across Europe, temperate and subtropical Asia, North Africa, and North America, with its centre of diversity in the Mediterranean region and East Asia. Species grow in grassland, scrub, rocky slopes, sea cliffs, and open woodland, mostly on well-drained soils.Suggested Uses
Used across the genus in sunny borders, gravel and coastal gardens, and herb plantings, with the shrubby B. fruticosum grown as evergreen hedging and screening. The umbels and bracts are cut for fresh and dried arrangements. Annual kinds suit wildflower and cutting beds.How to Identify
Appearance
Size & Dimensions
Height8" - 6'
Width/Spread8" - 5'
Colors
Bloom Information
Across the genus, yellow to yellow-green umbels appear from late spring through summer and into autumn, the timing varying with species and climate. The flowers and their leafy bracts hold well, and the shrubby B. fruticosum can flower for many weeks. Dry, ribbed two-parted fruits follow.
Detailed Descriptions
Flower Description
yellow to yellow-greenFoliage Description
green to blue-greenGrowing Conditions
Sun Requirements
Requires 6-10 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
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Most species grow in full sun on light, well-drained soil and tolerate poor, dry, stony, and alkaline ground, though a few prefer steadier moisture. The evergreen shrub B. fruticosum also withstands coastal wind and salt. Water during establishment, then rely on rainfall for the drought-tolerant species. Annual species are raised from seed sown in place and often self-sow for following years. Cut perennials and shrubs back after flowering to keep a compact shape. Feeding is seldom needed and rich soil can weaken stems.Pruning
For the shrubby species, trim after flowering to keep a dense, rounded form, cutting into leafy wood. Cut herbaceous perennials to the base in late autumn or late winter. Remove spent umbels from annuals to limit self-seeding.Container Growing
Suitable for container growing
Minimum container size: 3 gallons