Bunium bulbocastanum
great pignut
Central and southern Europe and western Asia
Overview
Bunium bulbocastanum is a tuberous perennial in the carrot family, growing 12-24 inches (30-60 cm) tall from a rounded underground tuber 0.75-1.5 inches (2-4 cm) across. The basal leaves are finely divided into thread-like segments, resembling those of carrot or chervil, and die back by midsummer. In early summer it produces flat-topped umbels 1.5-3 inches (4-8 cm) wide of small white flowers on slender, branching stems. These are followed by ridged, oblong seeds about 0.15 inch (4 mm) long, which are dried and used as a culinary spice with a flavor close to cumin. The dark tuber is edible raw or cooked and has a sweet, nutty taste, giving the plant its earthnut and pignut names. Plants are slow to reach flowering size, often taking two to three years from seed. Bunium bulbocastanum grows in full sun to light shade on light, well-drained soil and tolerates dry conditions once the tuber forms. The foliage closely resembles several toxic members of the carrot family, so identification from wild plants carries risk. Growth is sparse in heavy, wet soil, where the tuber is prone to rot. The species spreads slowly by seed where conditions suit it.
Native Range
Bunium bulbocastanum is native to central and southern Europe and parts of western Asia, where it grows in dry grassland, field margins, and open rocky ground on calcareous soils.Suggested Uses
Grown in herb gardens, dry borders, and naturalistic plantings for its edible tuber and cumin-flavored seed, spaced 8-12 inches (20-30 cm) apart. Combined with other meadow perennials on light soils. The early-summer umbels draw small pollinating insects.How to Identify
Appearance
Size & Dimensions
Height1' - 2'
Width/Spread8" - 1'
Reaches mature size in approximately 3 years
Bloom Information
White umbels open in early to midsummer, June into July in most regions, lasting three to four weeks. Ridged seeds ripen by late summer and are collected as a spice. The basal foliage yellows and dies back as flowering finishes.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 4-10 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
Grow in full sun to light shade on light, free-draining soil, including chalky and sandy ground. Water occasionally during dry spells in the first season; once the tuber forms the plant tolerates drought. Sow seed in autumn, as it needs a period of winter cold to germinate the following spring. Lift tubers after the foliage dies back if they are wanted for the kitchen. Heavy, wet soil rots the tuber and thins the stand. Growth is slow, with two to three years from seed to first flowering.Pruning
No routine pruning is needed. The spent flower stems are cut or left after seed ripens, depending on whether self-seeding is wanted. Yellowed foliage is removed once it dies back in summer.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Container Growing
✓ Suitable for container growing
Minimum container size: 3 gallons