Cephas · CC BY-SA 4.0
Skirret
Plant·Sium sisarum
Full sun
Sun
Medium
Water
Moist soil
Drainage
Zones 4–9
Hardiness
Skirret (Sium sisarum) is a plant. It grows best in full sun and has moderate water needs.
Through the year
DormantFloweringFruiting
Works well with
from wiki dataNo companions recorded.
WHAT IT NEEDS
Wants full sun
Needs moderate water
Tolerates moist soil, as long as it drains well
Prefers soil pH 6–7.5
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Prefers loam, silt soil
Struggles in compacted soil
Draws up potassium from deep in the soil
Adds a moderate amount of organic matter to the soil
WHAT IT GIVES
Gives mulch biomass (moderate)
Provides potassium
Attracts pollinators
HOW IT GROWS
SIZE & SPACING
Herbaceous
Height60–120 cm
Spacing30 cm (min 20 cm)
Root depthMedium
Width30–60 cm
Width figures are rough estimates, the most variable measurement in our data.
AI estimate · accuracy improves as growers contribute corrections.
HOW TO PROPAGATE
Propagate by seed, division
Difficulty
Establishes in about 1 yr
Self-seeds readily on its own
Where this comes from
Parsed11 Sept 2026
ConfidenceNot recorded
Photograph Cephas · CC BY-SA 4.0