How to Grow Celery UK

Watch: Growing Celery at Home

A SoilCommander video on growing celery at home in the UK — sowing, spacing, keeping the soil constantly moist, and harvesting crisp stalks.

Regional Planting Calendar

Region	Sow	Plant out
Southern England derived	early March to mid April	mid May to mid June
Midlands derived	early March to mid April	early June to late June
Northern England derived	mid March to late April	early June to early July
Scotland derived	early April to early May	late June to mid July

Rows marked derived are interpolated between regions our sources do state, because no source we consulted gives a figure for that region specifically. They are deliberately wider to reflect that uncertainty.

Southern England - detail & sources

Southern England: sow indoors mid-Mar to mid-Apr (min 15°C germination, RHS); plant out late May to mid-June once frost risk has passed. Longest, warmest season in the UK supports both self-blanching and trench celery.

Midlands - detail & sources

Midlands: sow indoors late-Mar to late-Apr; plant out early to late June, slightly later than southern England to avoid a late cold check that can trigger bolting (RHS).

Northern England - detail & sources

Northern England: sow indoors late-Mar to late-Apr; delay planting out to mid-June to early-July until night temperatures reliably stay above about 10°C (RHS bolting-risk threshold) and frost risk has passed.

Scotland - detail & sources

Scotland: sow indoors April; plant out late June to mid-July, the shortest safe window in the UK -- later, cooler springs raise bolting risk, and self-blanching types need to bulk up before the earlier autumn frosts arrive.

Quick Facts

Factor	Value
Soil pH	5.8 - 6.8
Germination temp	15°C
Optimal growing temp	18-25°C
Minimum survivable temp	-2°C
Time to harvest	70-84 days
Soil texture	RHS: "Fertile, moisture-retentive soil. Avoid sites where the soil dries out rapidly".
Drainage	RHS: moisture-retentive rather than free-draining, in a sunny spot. Utah State: "Full sun".
Lifecycle	biennial
Edible parts	stems (petioles)

At a Glance

Soil & Growing Conditions

Water: RHS: a "Steady supply of moisture throughout the growing season"; the "soil should never be allowed to dry out". Utah State: "at least 1 to 2 inches of water from rainfall or irrigation each week".

Humidity: No published ambient-humidity range; RHS and Utah State both specify constant soil moisture instead ("soil should never be allowed to dry out"; 1-2in/week) as the operative requirement for celery.

Soil pH range

5.8 6.8

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Growth Stages

Stage	BBCH	Notes
Sowing & Establishment	0	Sow indoors mid-March to early April. PLANTING DEPTH & SPACING: surface-sow thinly on moist compost with only a very light dusting of sieved compost/vermiculite over the seed -- celery seed needs light to germinate and a minimum temperature of 15°C (RHS), taking up to three weeks. Prick out and pot on seedlings once large enough to handle; harden off before planting out in late May to early June, once frost risk has passed and roughly 10-12 weeks after sowing (Utah State: 10-12 weeks to transplant). Space self-blanching/block plantings 23cm (9in) apart each way (RHS); space trench celery 30-45cm (12-18in) apart in a single row, or use 18-24in (46-61cm) row spacing per Utah State guidance. Never let young plants sit below about 10°C (50°F) for more than a few days once growing -- prolonged chilling triggers bolting (RHS).
Vegetative (Leaf Stalk) Growth	3	Plants build a rosette of leaf stalks. Celery has a small, shallow root system and forages poorly for water and nutrients (Utah State), so keep the soil constantly moist -- RHS: the soil "should never be allowed to dry out"; Utah State recommends at least 1-2in (25-50mm) of water a week from rainfall or irrigation. Mulch with 5cm+ of organic matter after planting to conserve moisture (RHS). Feed with a nitrogen-rich fertiliser about a month after planting to sustain leaf growth (Utah State). Any water stress at this stage causes stringy, strongly flavoured stalks later (Utah State).
Stalk Thickening & Blanching	4.1	Once self-blanching plants' stems reach about 30cm (1ft), tie or wrap the outer stems with newspaper or cardboard in mid-to-late summer to exclude light and sweeten the inner stalks (RHS); trench celery is instead earthed up gradually -- soil mounded around the stems in stages from late summer -- to blanch it (RHS). Continue steady watering and feeding, but stop nitrogen feeding once stalks begin to swell, to reduce the risk of splitting (Utah State). Protect self-blanching celery with fleece or cloches ahead of the first autumn frosts, as it is not hardy (RHS); earthed-up trench celery tolerates more cold and can stand later into autumn.
Maturation & Harvest	8	Self-blanching/green celery is ready mid-summer to autumn; trench celery matures later, from late autumn into early winter (RHS). Harvest as soon as it reaches the desired size and before outer leaves start to yellow (RHS) -- typically 70-84 days from transplanting. Utah State: pick outer petioles once a foot (30cm) or more long, or lift whole plants once 3in (7.6cm) or more in diameter. Dig up whole self-blanching plants for use since they do not store well in the ground; lift trench celery as needed through autumn/winter. Refrigerate harvested stalks for up to about 2 weeks (Utah State); RHS gives no specific storage method, reflecting best-used-fresh practice.

Harvest & Storage

When to pick: RHS: harvest "Once it reaches the desired size"; self-blanching types should be cut "before the leaves start to turn yellow". Utah State: "Harvest celery stalks by removal of the outer petioles when they are a foot or more in length. Whole plants are ready to use when they are 3 inches or more in diameter."

Storage

Utah State: "Store harvested celery in the refrigerator for up to 2 weeks". RHS states no storage method.

Diseases

Cucumber mosaic virus

Moderate to severe when it occurs -- RHS: causes stunting (shortened internodes), yellow mottling/mosaic, leaf curling and reduced yields; aphid-borne and erratic/unpredictable in occurrence (UC IPM).

Cucumber mosaic virus (CMV)

RHS names celery explicitly: "CMV also attacks spinach, lettuce and celery".

Celery leaf spot

High -- UC IPM/RHS: the most destructive foliar disease of celery; untreated infections coalesce, causing leaves to die and drop, giving stands a scorched appearance and reducing marketable yield.

Septoria apiicola

Pests

Celery leaf miner (celery fly)

Mainly aesthetic on established plants -- RHS: leaf blotching from mining, worse in the second (later-summer) generation which can stunt growth; chemical control not recommended.

Euleia heraclei

Carrot fly

Occasional/host-shared -- RHS lists celery among carrot fly hosts (carrot, parsnip, parsley, celeriac, celery) alongside carrot as the primary host; celery-specific severity is not separately rated by RHS.

Psila rosae

RHS: carrot fly affects "Carrot, parsnip, parsley, celeriac and celery".

Nutrient Issues

Boron (B)

deficiency

Correction

RHS symptom in celery: "Brown cracks in celery stalks". Boron is "less available in alkaline soils (above pH 7)". Correction: test soil pH and avoid liming already-alkaline soil; short term, fritted trace elements containing boron before sowing or planting.

Celery, Sown to Stalk

Seedlings ready to plant out

Celery seed needs light to germinate and a minimum of about 15°C, taking up to three weeks. Seedlings are pricked out and potted on before hardening off.

Potted on and hardening off

Young celery grows on in modules or pots until roughly 10-12 weeks after sowing, when it is hardened off and planted out once frost risk has passed.

A young plant establishing

Once planted out, celery builds a rosette of ridged, hollow stalks. It has a small, shallow root system, so the soil must never be allowed to dry out.

Close-up of the stalk base

The tightly packed leaf stalks (petioles) fan out from a central crown at soil level — the part that thickens and is blanched before harvest.

A UK celery field

On a larger scale, celery is grown in long, closely spaced rows on fertile, moisture-retentive soil — the same conditions a home bed needs, just at field size.

Mature plants, garden-grown

By late summer, well-watered plants form dense, upright bunches of stalks and leaves, ready to be blanched or cut as self-blanching celery.

Lifted whole, roots and all

Self-blanching celery does not store well in the ground, so whole plants are dug up for use rather than picked stalk by stalk.

A harvested head, ready to use

Harvest as soon as the plant reaches a usable size and before the outer leaves start to yellow. Celery is best used fresh, or refrigerated for up to about two weeks.

Left to flower (bolted)

Celery is a biennial: if it is checked by cold or left in the ground into its second year, it runs up tall flowering stems instead of staying leafy and tender.

Regrowing from a kitchen scrap

Celery will resprout from the cut base of a shop-bought head stood in water or damp compost — a fun way to see fresh leaves appear within days.

References

1. AHDB - Celery leaf spot
2. EPPO Global Database - Apium graveolens (APUGV) Overview

   EPPO code for the species Apium graveolens (distinct from var. dulce APUGD stalk-celery cultigen code and var. rapaceum APUGR celeriac).

3. FAO EcoCrop - Apium graveolens var. dulce data sheet
4. Michigan State University Extension - Bolting in spring vegetables

   US extension source on the mechanism: celery has a juvenile period of two to twenty leaves, after which it vernalises when exposed to 35-48°F for two to twelve weeks; it devernalises above 68°F. Celery needs a larger plant and a longer exposure to vernalise than celeriac.

5. NC State Extension Gardener Plant Toolbox - Apium graveolens (Celery, Smallage, Wild Celery)
6. Plants of the World Online, Royal Botanic Gardens, Kew - Apium graveolens L.

   Kew POWO: native range Macaronesia to North Africa, Europe to West Himalaya; biennial habit, temperate biome.

7. Royal Horticultural Society - Carrot fly
8. Royal Horticultural Society - Celery Leaf Mining Fly | RHS Advice
9. Royal Horticultural Society - Cucumber mosaic virus
10. Royal Horticultural Society - How to grow Celery | RHS Guide
11. Royal Horticultural Society - Nutrient deficiencies
12. Texas A&M AgriLife Extension (Aggie Horticulture) - Celery (vegetable archives)

    US extension corroboration on frost/cold tolerance: young plants damaged near freezing; mature plants can withstand light frost but temperatures much below 30°F (-1°C) can kill/damage; used to correct an overstated -5°C survivable-minimum.

13. Utah State University Extension - Celery in the Garden
14. Utah State University Extension - Celery in the Garden (Fruit and Vegetable Guide Series)

    US extension source: planting window, 10-12wk to transplant, 18-24in spacing, small/shallow root system needing consistent nutrients, 1-2in/week water, N feed timing, stop feed once stalks form, refrigerate up to 2 weeks.

14 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.