How to Grow Skirret UK
On this page
In the UK, skirret goes in the ground early April to early May.
Timing is the decision that matters most in the UK: sowing early April, and that same window applies across all 4 regions covered here.
Core growing advice on this page is checked against named horticultural sources — see References.
Skirret (Sium sisarum)
Also known as: crummock · 4 sources cited · Verified
When to Plant Skirret in the UK
When to plant skirret in the UK: in Southern England, sow early April to early May. Find your area in the table below.
Quick Facts
At a Glance
Soil & Growing Conditions
Growth Stages
Harvest & Storage
Pests
Skirret, the Sweet-Rooted Perennial the Tudors Grew
Plan your Skirret planting
When to sow and plant Skirret depends on your own frost dates. Check the UK vegetable planting calendar. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.
Growing Skirret in another region
Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.
References
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Specialist grower guide for unusual root crops. Direct sow mid-autumn to late spring, or start indoors 8 weeks before last frost for full-size first-year roots; seed germinates slowly and erratically, first germinations around 3 weeks and 50% emergence by week 6, helped by consistent moisture and bottom heat. Propagates easily from offsets ringing the stem -- select offsets with large shoots and rootlets, pot them with the sprout tip just below the surface, which improves survival over direct planting. Space 18in apart in rows 3ft apart, sowing seed about 1/8in deep. Acidic to neutral, well-drained soil rich in organic matter; responds to nitrogen and tolerates heavy, swampy ground. Full sun optimal, tolerates shade with reduced yields. Harvestable after the first year once foliage dies back, with yields improving markedly in year two. DISAGREES WITH RHS ON TWO POINTS: says frost does NOT appear to improve the roots (commonly claimed elsewhere), and names black blight (Septoria) as a major disease threat plus root knot nematodes, where RHS reports the plant as generally disease-free. Pests: voles eat the roots; tiny seed-feeding beetles damage flower heads.
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A secondary gardening reference rather than a university or horticultural authority, used for propagation-method and timing detail RHS's basic profile does not cover, not contradicted by it. Can be grown from seed or from a purchased crown/root offset for a head start. A hardy, cool-season crop, directly sown after all danger of frost, or started indoors for transplant eight weeks before the last frost, with harvest six to eight months later. Grows 3-4ft tall with large, glossy, dark green, compound pinnate leaves and greyish-white roots clustering from the base.
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PFAF entry for Sium sisarum. Fetched and parsed directly for the USDA hardiness rating.
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A herbaceous perennial formerly cultivated as a root vegetable before potatoes arrived in Britain. White roots harvested when the plant is dormant (autumn to early spring), tasting like a mixture of sweet carrots and parsnips. Also ornamental, with delicate white flower umbels in summer. Native to Europe and East Asia, not native to GB/Ireland. Hardiness H6 (-20 to -15°C). Full sun; benefits from south-, west- or east-facing aspects. Soil: chalk, clay, loam or sand; acid, alkaline or neutral pH; moist but well-drained. Height 1-1.5m, spread 0.1-0.5m. Time to maturity 1-2 years. Propagate by seed. Pests: susceptible to stem and bulb eelworm; voles may eat roots. Diseases: generally disease-free. Lift and divide clumps when dormant (November-March), harvesting roots for culinary use while replanting sections for continued growth.
4 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.
Frequently Asked Questions
When should I sow skirret in the UK?
In Southern England, from early April. In Scotland, wait until early April. Treat these as a guide rather than a fixed date — the governing rule is to sow only once frost risk has passed and temperatures are reliably warm enough.
When do I sow skirret?
Sow early April to early May.
Plan next season before the problems start
Most of the advice on this page comes down to timing and spacing — sowing at the right moment, rotating beds, and giving plants enough airflow. The UK Garden Planner lays your plot out month by month so those decisions are already made before the season starts.
Get the UK Garden Planner →Instant PDF download · Written for UK growing conditions
How this guide is put together
The growing data on this page — sowing windows, pests, diseases, soil and site requirements — comes from named horticultural sources, listed in References below, checked against RHS and Met Office guidance. An automated pipeline assembles that verified data into the page you're reading: it selects which facts to lead with and builds the surrounding prose and layout. It does not invent a date, a source or a number — where a verified value for a field isn't available, the page leaves it out rather than guessing. A person reviews and publishes each page; nothing goes live unverified.
Last verified 2026-09-02
Plan Skirret by month
The months this guide gives for sowing or planting, each with the full list of jobs for that month in the UK:
More from the same group (roots & tubers):
Growing advice for your part of the UK
Timing and conditions change a lot inside one country. These guides cover frost dates and growing seasons region by region.
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Keep going
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.