How to Grow Alexanders UK
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In the UK, alexanders go in the ground early April to late 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.
Alexanders (Smyrnium olusatrum)
4 sources cited · Verified
When to Plant Alexanders in the UK
When to plant alexanders in the UK: in Southern England, sow early April to late May. Find your area in the table below.
Quick Facts
Soil & Growing Conditions
Growth Stages
Harvest & Storage
Alexanders, a Forgotten Pot Herb
Plan your Alexanders planting
When to sow and plant Alexanders 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 Alexanders 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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A secondary gardening reference rather than a university or horticultural authority, used for edible-parts/foraging/culinary detail RHS's garden-plant framing does not cover, not contradicted by it. Formerly widely grown as a pot herb across Europe, now appreciated mostly by foragers -- commonly found along coastal areas, hedgerows and waste ground. Easily identified by vibrant green, glossy leaves, yellowish-green flowers, and hollow stems. All parts of the plant are edible: leaves, stems, flowers, seeds, and roots, with a very strong celery-like taste. Older leaves and stems are typically cooked due to their bitterness.
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Biennial emerging in winter with dark-green SHINY leaves, pinnately compound and trifoliate in groups of three lobed, finely toothed leaflets, with a distinctive red-veined sheath at the base of each leaf stem; cream-yellow umbels in spring; seeds dark green turning black and hardening with age. TOXIC LOOK-ALIKE: hemlock water-dropwort, deadly poisonous, distinguished by much more deeply lobed and/or toothed leaflets and leaves that are NOT shiny. Wild celery is edible and has white flowers, unlike the yellow of Alexanders. Whole plant usable -- young shoots and leaves raw or cooked, older leaves cooked, stems raw or cooked, roots cooked, seeds ground as a condiment -- available winter through summer. Explicit warning: be 100% sure of identification, and those with a celery allergy should do a tolerance test as this is a carrot-family plant.
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PFAF entry for Smyrnium olusatrum. Fetched and parsed directly for the USDA hardiness rating.
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A vigorous semi-evergreen biennial reaching 75-120cm tall, with a solid stem that becomes hollow and grooved with age. Greenish-yellow flowers with a pungent, myrrh-like scent, in umbrella-like clusters. Native to the Mediterranean, also native to GB/Ireland. Hardiness H6 (-20 to -15°C). Full sun, south-, west- or east-facing aspect, sheltered. Soil: sand, clay, chalk, loam; moist but well-drained or well-drained; neutral, acid or alkaline pH. Height 1-1.5m, spread 0.1-0.5m. Time to maturity 1-2 years. Propagate by seed. Generally pest-free and disease-free. Best grown in free-draining soil in full sun; grows well in coastal areas.
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 alexanders 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 alexanders?
Sow early April to late 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 Alexanders 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 (herbs & aromatics):
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.