Herbculinary herbSome care needed

Coriander

Coriandrum sativum

Two crops from one plant, and they pull in opposite directions: grown for leaf it must be kept from flowering, grown for seed it must be allowed to. Coriander bolts readily — from heat, from long days and from any check to growth, including being transplanted — so it is direct-sown, sown often, and never expected to last.

Position: Full sun or Partial shade
Water: moderate demand
Drainage: Free-draining, Moisture-retentive
Grows to: 30–60 cm × 20 cm
Hardiness: H3
Harvest: June to October
Difficulty: Some care needed

Described view

A coriander plant beginning to bolt, showing the finely divided upper leaves and elongating flower stem quite unlike the broad lower leaves

August

Sow outdoors · In flower · Harvest

Coriander’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

Activity	A	M	J	J	A	S	O
Sow outdoors	April.	May.	June.	July.	August.
In flower			June.	July.	August.
Harvest			June.	July.	August.	September.	October.

Names that cause confusion

cilantro — The same plant. In North American usage 'cilantro' is the leaf and 'coriander' the seed; in British usage 'coriander' covers both.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

Sow outdoors
from 2 weeks before to 16 weeks after your last spring frost, every three weeks — this is the crop that most needs successional sowing
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Coriander — sowing
Checked 2026-08-13
Sow where it is to grow. Coriander bolts if transplanted.

What kind of herb this is

Herbs are a kitchen grouping rather than a botanical one, and the plants in it want opposite things. This is the one distinction that decides how to treat it.

Cool-season leafy herb

Growing regime

source

Sourced guidancehigh confidence

Royal Horticultural Society: Coriander — growing

Checked 2026-08-13

Grows fast in cool moist conditions and runs to flower in heat or drought. Sow little and often rather than trying to keep one sowing going through summer.

Treated the same way: chervil, dill, parsley. The herb bed, split by regime

Indoors: Indoors spring to autumn

Where the indoor assessment comes from

IndoorsSourced guidancemoderate confidence: Royal Horticultural Society: Coriander — growing indoors
Checked 2026-08-13

Almost any herb will sit on a windowsill in July. This is about whether it is still there in March, which is the part a pot on a supermarket shelf does not tell you.

What happens when it flowers

On a herb this is rarely a problem and rarely nothing. It is the point at which the plant stops being what you grew it for — by a lot, a little, or not at all.

Ends leaf production

source

Sourced guidancehigh confidence

Royal Horticultural Society: Coriander — harvesting

Checked 2026-08-13

The seed is a crop too

Nothing reverses it, and pinching the flower stem out only delays the plant by days. The useful response is to let it finish and collect the seed, which is coriander in its other form, and to sow a fresh batch every three or four weeks rather than trying to keep one going.

source

Sourced guidancehigh confidence

Royal Horticultural Society: Coriander — bolting

Checked 2026-08-13

Conditions it needs

Light: Full sun, Partial shade
Direct sun: 4 hours a day or more
Frost: Half hardy
Hardiness rating: H3 (RHS)
Grows best at: 15–22 °C
Germinates at: 10–25 °C
Soil: Loam, Peat-free compost, Sandy
Soil pH: 6–7.5
Drainage: Free-draining, Moisture-retentive
Water needs: moderate
Drought: poor tolerance
Waterlogging: poor tolerance
Heat: poor toleranceSourced guidanceDepends on conditions
Wind and exposure: moderate tolerance

Where these figures come from

LightSourced guidancehigh confidence

Partial shade in summer delays bolting slightly.

Royal Horticultural Society: Grow your own: coriander

Checked 2026-08-13

Direct sunHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

FrostSourced guidancehigh confidence

Royal Horticultural Society: Coriander — hardiness

Checked 2026-08-13

Hardiness ratingSourced guidancehigh confidence

Royal Horticultural Society: RHS hardiness ratings

Checked 2026-08-13

Grows best atHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Germinates atSourced guidancehigh confidence

OSU Extension Service — Oregon State University: Herb seed germination temperatures

Checked 2026-08-13

SoilHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Soil pHSourced guidancehigh confidence

University of Minnesota Extension — University of Minnesota: Growing herbs

Checked 2026-08-13

DrainageHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Water needsHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

DroughtHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

WaterloggingHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

HeatSourced guidanceDepends on conditionshigh confidence

Applies when: Heat and long days both trigger bolting; a midsummer sowing may flower within a month.

Home and Garden Information Center — Clemson Cooperative Extension: Coriander — culture

Checked 2026-08-13

Wind and exposureHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

Soil	Verdict	Why
Heavy clay	Works, with one condition	Coriander will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Sandy	Works, with one condition	Coriander will crop on sandy, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Chalky and alkaline	Works, with one condition	Coriander will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Loam	Prefers this soil	Loam suits Coriander as it stands: The pH suits it: it wants 6 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Silty	Prefers this soil	Silty suits Coriander as it stands: The pH suits it: it wants 6 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. The soil holds moisture, which saves a great deal of watering.
Peaty and acid	Works, with one condition	Coriander will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rock	Works, with one condition	Coriander will crop on shallow over rock, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Made ground and urban soil	Works, with one condition	Coriander will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height: 30–60 cm
Mature spread: 20 cm
Rooting depth: 25 cm
Spacing: 15–20 cm apart

Where these figures come from

Mature heightHorticultural consensusmoderate confidence

Taller once it bolts and runs up to flower.

No external citation — see the evidence type above.

Checked 2026-08-13

Mature spreadHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Rooting depthHorticultural consensusmoderate confidence

A taproot, which is why it resents transplanting.

No external citation — see the evidence type above.

Checked 2026-08-13

SpacingSourced guidancehigh confidence

Royal Horticultural Society: Coriander — spacing

Checked 2026-08-13

Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

In a container

Minimum volume: 5 litres or more
Minimum depth: 20 cm

Where the container figures come from

Minimum volumeSourced guidancehigh confidence: Royal Horticultural Society: Herbs in containers
Checked 2026-08-13
Minimum depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Sow direct into the final pot rather than transplanting, and sow a fresh pot every three weeks — a container of coriander bolts sooner than one in the ground because the compost warms faster. Deep enough for the taproot, and never let it dry out.

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

Method	Suitability	What it needs
Open ground	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Coriander Checked 2026-08-13
Raised bed	Well suited source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Traditional dug bed	Well suited source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Container	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Herbs in containers Checked 2026-08-13	20 cm of depth; Sown direct rather than transplanted
Windowsill	Workable Horticultural consensusDepends on conditionsmoderate confidence Applies when: Works as a cut-young leaf crop; a windowsill plant kept warm bolts sooner than an outdoor one. No external citation — see the evidence type above. Checked 2026-08-13
Polytunnel	Workable source Sourced guidancemoderate confidence Agriculture and Horticulture Development Board — AHDB: Herbs under protection Checked 2026-08-13	Extends the season at both ends.
Hydroponics	Workable source Sourced guidancemoderate confidence Purdue Extension — Purdue University: Hydroponic herbs Checked 2026-08-13
Vertical growing	Workable source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Aquaponics	Workable source Sourced guidancemoderate confidence Purdue Extension — Purdue University: Aquaponic herbs Checked 2026-08-13
Greenhouse	Workable source Sourced guidancemoderate confidence Agriculture and Horticulture Development Board — AHDB: Herbs under protection Checked 2026-08-13

Growing it

SowingSow 1–2 cm deep directly where the plants are to grow, and sow again every three weeks. Coriander has a taproot and bolts when moved, so module-raising it is counterproductive.1–2 cm
HarvestingCut outer leaves as needed once the plant has several stems. Cutting the whole plant back hard rarely produces a useful second flush; sowing again is more reliable.
WateringWater steadily and never let it dry out. Coriander reads any check to growth as a signal to flower, and drying out is the commonest check there is — a plant wilted once on a hot afternoon will often bolt within the fortnight, whatever is done afterwards. Water in the morning at the base, keep the soil evenly damp rather than wet, and mulch if the bed bakes.
FeedingCoriander for leaf needs no feeding in reasonable soil; it is a fast crop taken young and pulled. Where the same pot is being cut repeatedly, a weak liquid feed keeps the later cuts from yellowing, but rich soil is not the answer to a bolting plant — sowing again is. Coriander grown for seed wants nothing at all.
ThinningThin leaf coriander to about 15 cm, or leave a broadcast patch dense and cut it whole as seedlings — both work, and half-thinning is what does not. Plants left crowded but not cut compete, run up early and give a small leaf crop. If you want seed, thin properly: a well-spaced plant carries far more umbels.
ProtectionCoriander is an annual and is not overwintered — plants killed by frost have finished their life rather than failed. What does work is an August or early-September sowing under a cloche, in a cold frame or in a pot in an unheated greenhouse: the cool short days suit it far better than midsummer does, it bolts much more slowly, and it will crop into winter and again early in spring. Leaves take a light frost; a hard one ends it.

Where this guidance comes from

SowingSourced guidancehigh confidence: Royal Horticultural Society: Coriander — sowing
Checked 2026-08-13
HarvestingHorticultural consensusmoderate confidence: Royal Horticultural Society: Coriander — harvesting
Checked 2026-08-13
WateringSourced guidancehigh confidence: Royal Horticultural Society: Coriander — cultivation
Checked 2026-08-13
FeedingSourced guidancehigh confidence: Royal Horticultural Society: Coriander — cultivation
Checked 2026-08-13
ThinningSourced guidancehigh confidence: Royal Horticultural Society: Coriander — sowing
Checked 2026-08-13
ProtectionSourced guidancehigh confidence: Royal Horticultural Society: Coriander — sowing times
Checked 2026-08-13

Is it worth putting under cover?

Whether it will grow there is on the methods table above. This is whether the space is well spent, which is a different question and usually the one being asked.

Structure	What protection is worth	What decides it
Greenhouse	Extends the season source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Bolting. Coriander runs to seed fast in heat, so a greenhouse is useful in March and September and actively unhelpful in July.The seasonality inverts here relative to most crops: the protected window is at the ends of the year rather than the middle.
Polytunnel	Extends the season source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Bolting, on the same inverted seasonality.

On a windowsill

A few weeks, then replace

source

GrowingHQ editorial positionmoderate confidence

How long the crop is actually productive on an ordinary British windowsill without added light.

GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

A supermarket pot or a sowing gives a few weeks of cutting and is then exhausted. That is what the crop is, not a failure to keep it alive. Bolting and a taproot. Coriander resents being moved and runs to seed at the first check, so a pot gives one or two cuts rather than a standing supply.Sow it where it is to grow and re-sow every few weeks. There is no way to make one pot last.

Growing it without soil

Nearly anything can be grown in a soilless system by somebody with enough equipment. The useful question is whether it is worth it, in which technique, and what goes wrong.

Works with conditions

Succeeds when the conditions listed here are met and fails when they are not. The conditions are the answer, not a caveat.

source

Sourced guidancemoderate confidence

Purdue Extension — Purdue University: Hydroponic herbs

Checked 2026-08-13

Grows well and bolts quickly. Treat it as a repeated short crop rather than a standing planting.

Techniques that suit it

Nutrient film (NFT)A shallow stream of solution runs over bare roots in a sloped channel. Cheap and productive for small fast crops; a pump failure kills a crop within hours because there is no reservoir at the roots.
Drip-fed mediumSolution is dripped into an inert medium around each plant. The most forgiving technique and the one that suits large, long-season, heavy crops.
Ebb and flowA bed of inert medium floods and drains on a timer. The medium holds moisture between floods, which makes it far more tolerant of interruption than NFT.

source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Root space: A taproot, which suits a medium bed better than a bare channel.
Lighting: Needs supplementary light
pH band: 5.5–6.5

Where these figures come from

Root spaceHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

LightingHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

pH bandSourced guidancehigh confidence

Outside roughly this band, individual nutrients become unavailable even when they are present in the solution — which is why a crop can starve in a full reservoir.

Purdue Extension — Purdue University: Hydroponic solution management — pH

Checked 2026-08-13

What actually goes wrong

Bolting. Coriander runs to seed faster than any other herb here, and warm indoor conditions accelerate it — successional sowing matters more than technique.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Coriander — bolting
Checked 2026-08-13

No nutrient recipes here

GrowingHQ records pH bands, which are measurable properties of nutrient availability, and deliberately records no EC or PPM targets and no mixing instructions. Published targets vary by cultivar, growth stage, water source and technique, and the figures that apply to your system are on the product you bought.

Harvesting

Time from sowing or planting: 4–8 weeks

source

Sourced guidancehigh confidence

Royal Horticultural Society: Coriander — timing

Checked 2026-08-13

When it is readyPick leaves from four to six weeks after sowing. Once a central stem elongates the leaf crop is over — but leave the plant to flower and set seed, which is a crop in itself and feeds hoverflies while it does it.
How to pick itCut outer leaves at the base, or the whole plant when young.
Keeping itLeaves keep a few days refrigerated and do not dry well. Seed dries and stores for years.

Where the harvest guidance comes from

When it is readySourced guidancehigh confidence: Royal Horticultural Society: Coriander — harvesting
Checked 2026-08-13
How to pick itHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Keeping itHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

What goes wrong

Problem	How often	Notes
Bolting	common source Sourced guidancehigh confidence Royal Horticultural Society: Coriander — bolting Checked 2026-08-13	The defining characteristic of the crop rather than an occasional problem.
Slugs and snails	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Aphids	uncommon source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13

Start from what you can see

Plant running up to flower before it is ready to eat

Grown with, grown after, grown instead

Every relationship states its mechanism. A pairing nobody can explain is a pairing nobody has checked, and it does not go in.

Closely relatedDill
Both Apiaceae grown for leaf and seed, both taprooted, both direct-sown and both quick to bolt. Their guidance is close enough that a grower who can manage one can manage the other.
source
Sourced guidancehigh confidence
Plants of the World Online — Royal Botanic Gardens, Kew: Apiaceae
Checked 2026-08-13
Grown togetherBroad bean
Coriander allowed to flower produces umbels that are heavily worked by hoverflies, whose larvae are significant aphid predators — which is directly relevant next to a crop whose main pest is blackfly.
Sourced guidanceDepends on conditionshigh confidence
Applies when: The mechanism — umbellifer flowers supporting hoverfly populations — is well established. The size of the effect on any one crop in a garden is not quantified, and it requires letting the coriander flower rather than picking it.
Garden Organic — Garden Organic (Henry Doubleday Research Association): Encouraging natural enemies
Checked 2026-08-13

Sources for this page

Agriculture and Horticulture Development Board · GrowingHQ editorial synthesis · Home and Garden Information Center · OSU Extension Service · Purdue Extension · Royal Horticultural Society · University of Minnesota Extension

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-13.

If something is wrong with it

Plant running up to flower before it is ready to eat — 2 causes GrowingHQ holds for coriander

Something else? Work through it with the diagnostic tool.