Laserpitium siler
Sermountain
Overview
Laserpitium siler is a clump-forming herbaceous perennial in the carrot family, reaching 24-48 inches (60-120 cm) tall and 18-24 inches (45-60 cm) wide. Stems are stout and branched, rising from a basal rosette of blue-green, twice-pinnate leaves with leathery, oval leaflets 1-2 inches (2.5-5 cm) long. Flat-topped compound umbels 3-5 inches (8-13 cm) across carry small white to cream flowers in early to midsummer. Winged, ribbed seeds follow the flowers. The blue-green foliage holds its color through the season. Plants form a deep taproot, which makes established clumps difficult to move. Growth is slow from seed, with plants taking 2-3 years to reach flowering size.
Native Range
Native to the mountains of central and southern Europe, from the Alps and Pyrenees to the Balkans, where it grows on limestone slopes, in open woodland, and on rocky grassland at montane and subalpine elevations.Suggested Uses
Grown in gravel gardens, dry sunny borders, and naturalistic prairie-style plantings, spaced 18-24 inches (45-60 cm) apart. Combines with grasses and other deep-rooted perennials on free-draining soil. The umbels and seed heads suit wildlife-oriented and pollinator plantings.How to Identify
Appearance
Size & Dimensions
Height2' - 4'
Width/Spread1'6" - 2'
Colors
Flower Colors
Foliage Colors
Bloom Information
Blooms in early to midsummer, June to July, with umbels remaining in flower for 3-4 weeks. Seed heads follow and persist into autumn.
Detailed Descriptions
Foliage Description
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
Care & Maintenance
Care Guide
Grows in full sun to part shade in well-drained, alkaline to neutral soil, including dry and rocky ground. Established plants tolerate drought through their deep taproot but dislike waterlogged winter soil, which causes crown rot. The taproot makes transplanting difficult, so plants are usually raised from seed in their final position. Aphids may gather on flower stems. Little routine care is needed once established. Plants are long-lived where drainage is good.Pruning
Cut flower stems to the base after seed has set, or leave the ribbed seed heads for winter structure. Remove dead foliage in late winter before new growth. No other pruning is needed.Pruning Schedule
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winterearly spring