GrowingHQ
Herbperennial herbSome care needed

Lemon thyme

Thymus citriodorus

Grown like common thyme and worth separating from it for two reasons: it is noticeably less hardy, and the variegated forms sold most often are weaker again. A lemon thyme lost over winter is usually a plant that would have survived as ordinary thyme in the same spot.

Position
Full sun
Water
low demand
Drainage
Free-draining
Grows to
20–30 cm × 30–40 cm
Hardiness
H4
Harvest
May to October
Difficulty
Some care needed

August

Harvest

Lemon thyme’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.

ActivityJFMAMJJASOND
PlantApril. May.
HarvestMay. June. July. August. September. October.
PruneMay.

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.

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.

Mediterranean woody herb

Growing regime
source

Sourced guidancehigh confidence

  • Royal Horticultural Society: Lemon thyme — growing

Checked 2026-08-13

Wants sun, poor free-draining ground and very little water once established. Far more of these die from winter wet at the roots than from cold air, so drainage matters more than hardiness ratings suggest.

Treated the same way: bay, borage, chamomile, hyssop, marjoram, oregano and 7 more in the same group. The herb bed, split by regime

Why winter wet kills a Mediterranean herbTwo soil cross-sections side by side. On the left, a well-drained planting: the crown of a rosemary sits slightly proud of the surrounding soil on a low mound, the root zone is open gritty soil with air between the particles, and arrows show winter rain moving down and away past the roots. The plant above is dense and well furnished. On the right, the same herb in heavy soil in a hollow: the crown sits level with or below the surface, the root zone is dense soil over a compacted pan, and winter rain has nowhere to go so a water table stands in the root zone from November to March. The roots there are drawn broken and dashed to show they have died, and the plant above is sparse and thin. The point is that the plant looks unharmed all winter because an evergreen with a full canopy asks almost nothing of its roots in January, so the loss only shows the following spring when it fails to grow.Sharp drainagecrown proud, water moves throughroots stay firm and paleair between the particles all winterWinter wetcrown in a hollow, water standswater table, Nov–Marcompacted pan — nowhere to goroots dark, soft and sourand the plant above still looks fineopen gritty soilheavy soilstanding waterliving rootsPlanting on a low mound, adding grit, or standing a pot on feet all do the same job: get the crown above the water.
The damage happens in January and shows in May. An evergreen herb asks almost nothing of its roots in winter, so a drowned root system stays invisible until the plant is asked to grow and cannot.
Indoors
Not worth growing indoors
Where the indoor assessment comes from
IndoorsSourced guidancemoderate confidence
  • Royal Horticultural Society: Lemon thyme — 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.

No real effect on the leaves
source

Sourced guidancehigh confidence

  • Royal Horticultural Society: Lemon thyme — harvesting

Checked 2026-08-13

Nothing to do about it. Flowering does not change what lemon thyme is worth picking, so there is no reason to prevent it.

Conditions it needs

Light
Full sun
Frost
Hardy
Hardiness rating
H4 (RHS)
Grows best at
12–26 °C
Soil
Sandy, Loam, Chalky
Soil pH
6–8
Drainage
Free-draining
Water needs
low
Drought
good tolerance
Waterlogging
poor tolerance
Heat
good tolerance
Wind and exposure
moderate tolerance
Where these figures come from
LightSourced guidancemoderate confidence
  • Royal Horticultural Society: Lemon thyme — position

Checked 2026-08-13

FrostSourced guidancehigh confidence
  • Royal Horticultural Society: Lemon thyme — hardiness

Checked 2026-08-13

Hardiness ratingSourced guidancemoderate confidence
  • Royal Horticultural Society: RHS hardiness ratings

Checked 2026-08-13

Grows best atSourced guidancemoderate confidence
  • Royal Horticultural Society: Lemon thyme — temperature

Checked 2026-08-13

SoilSourced guidancemoderate confidence
  • Royal Horticultural Society: Lemon thyme — soil

Checked 2026-08-13

Soil pHSourced guidancemoderate confidence
  • Plant Finder — Missouri Botanical Garden: Thymus citriodorus — culture

Checked 2026-08-13

DrainageSourced guidancemoderate confidence
  • Royal Horticultural Society: Lemon thyme — soil

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

HeatHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

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.

SoilVerdictWhy
Heavy clayWorks, with one conditionLemon thyme will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.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.
SandyPrefers this soilSandy suits Lemon thyme as it stands: The pH suits it: it wants 6 to 8, and this soil is in that range. The free drainage is exactly what it wants. Sandy soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test.
Chalky and alkalinePrefers this soilChalky and alkaline suits Lemon thyme as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test.
LoamPrefers this soilLoam suits Lemon thyme as it stands: The pH suits it: it wants 6 to 8, 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.
SiltyPrefers this soilSilty suits Lemon thyme as it stands: The pH suits it: it wants 6 to 8, 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 acidWorks, with one conditionLemon thyme 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. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.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 rockPrefers this soilShallow over rock suits Lemon thyme as it stands: The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test.
Made ground and urban soilWorks, with one conditionLemon thyme 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. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.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
20–30 cm
Mature spread
30–40 cm
Rooting depth
25 cm
Spacing
30–40 cm apart
Where these figures come from
Mature heightHorticultural consensusmoderate confidence

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

No external citation — see the evidence type above.

Checked 2026-08-13

SpacingSourced guidancemoderate confidence
  • Royal Horticultural Society: Lemon thyme — spacing

Checked 2026-08-13

How far apart to plant lemon thymeThree lemon thyme plants drawn in a row at their recorded spacing of 30–40 cm between plants. The spacing is drawn to scale against a one metre rule; the plants themselves are symbols rather than scale drawings, so the distance between them is the part to read.30–40 cmone metre
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 volumeHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Minimum depthHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Suits a pot, and a pot is also the easiest way to keep it alive over winter — stand it against a wall out of the rain from November. Lemon thyme is less hardy than common thyme, and a plant that is merely cold usually survives while one that is cold and sodden does not.

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.

MethodSuitabilityWhat it needs
Raised bedWell suited
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

ContainerWell suited
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

5 litres; Gritty free-draining compost
Open groundWorkable
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

Traditional dug bedWorkable
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

GreenhouseWorkable
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

PolytunnelWorkable
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

HydroponicsWorkable
source

GrowingHQ editorial positionmoderate confidence

As thyme, with the additional note that the variegation which makes it worth buying fades fastest in the low light a system usually supplies.

  • GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

WindowsillWorkable
source

Horticultural consensusmoderate confidence

  • Royal Horticultural Society: Growing herbs and salads indoors

Checked 2026-08-13

Growing it

  • ProtectionGrow it in a pot that can be moved under cover, or in the sharpest drainage you have. Lemon thyme is a grade less hardy than common thyme and the variegated forms less again, so the same border position does not carry across.
  • PropagationLayer a low shoot by pinning it to the compost in spring, or take cuttings in early summer. Named lemon thymes do not come true from seed, so anything sold as lemon thyme seed will not be the plant on the picture.
  • WateringTreat it as thyme with less margin for error. Established plants in free-draining ground want nothing; potted ones want a thorough soak and then to be left until dry. Because lemon thyme is the less hardy of the two, a wet root run through the winter is what usually kills it — a plant on the drier side in November stands a far better chance in February than a comfortable one.
  • FeedingNo feeding. The variegated forms sold most often are already weaker and slower than plain lemon thyme, and feeding them produces soft green growth that reverts, sprawls and rots rather than a better plant. Refresh the top few centimetres of compost in a pot each spring instead.
  • PruningTrim the whole plant over by about a third immediately after it flowers, cutting only into green leafy growth. This is the single operation that decides how long the plant lasts: a lemon thyme clipped every year stays dense and low for five or six seasons, and one left alone opens out into bare woody stems within three and cannot be brought back.
  • HarvestingPick sprigs through the growing season and lightly in winter, taking soft growth only. The lemon scent is strongest on new shoots, so a plant kept trimmed gives better leaves than one allowed to run to wood.
Where this guidance comes from
ProtectionSourced guidancemoderate confidence
  • Royal Horticultural Society: Thyme — care

Checked 2026-08-13

PropagationSourced guidancemoderate confidence
  • Royal Horticultural Society: Thyme — propagation

Checked 2026-08-13

WateringSourced guidancehigh confidence
  • Royal Horticultural Society: Thymus — cultivation

Checked 2026-08-13

FeedingSourced guidancehigh confidence
  • Royal Horticultural Society: Thymus — cultivation

Checked 2026-08-13

PruningSourced guidancehigh confidence
  • Royal Horticultural Society: Thymus — pruning

Checked 2026-08-13

HarvestingSourced guidancehigh confidence
  • Royal Horticultural Society: Thymus — harvesting

Checked 2026-08-13

Where to make a pruning cutFour stems compared. The first is cut cleanly on a slope about five millimetres above an outward-facing bud, sloping away from it, and is labelled correct. The second is cut too far above the bud, leaving a long stub that dies back. The third is cut too close, into the bud itself, which loses the shoot. The fourth is cut sloping towards the bud so rain runs onto it rather than away, which rots it. In every case the bud points outwards, away from the centre of the plant.Correct5 mm, sloping awayToo highstub dies backToo closebud lostSloping inrain sits on the bud
The bud you cut to becomes the new shoot, and it grows in the direction it points — which is why an outward-facing bud opens the plant up and an inward-facing one crosses the middle.
Four ways to make more plantsFour propagation operations compared, each showing where the separation is made and what must be present on both sides of it. Division: a clump cut between crowns, with roots and at least one growing point on every piece. Stem cutting: a shoot cut just below a leaf node, because the node is where roots form, with the lower leaves removed. Runner: a plantlet already rooting where it touches the ground, severed from the parent only after its own roots have taken. Offset: a young shoot at the base of the parent, separated with its own roots attached. In each case the cut is marked and the part that must be retained is labelled.Divisioncut between crownsroots on every piececut below a nodeStem cuttingroots form at the nodestrip the lower leavesRunnerlet it root firstthen sever the linkOffseta shoot at the basetake its roots with it
The rule is the same in all four: the new piece needs both a growing point and roots of its own. A cutting is the exception that has to make its roots afterwards, which is why the node matters so much.

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.

On a windowsill

Spring to autumn
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

 Productive from roughly March to October and not after. Growth stops when the light does, and a plant pushed through the dark months usually does not recover. Light and airflow, exactly as for thyme — and the variegated forms lose their colour fastest in poor light, which makes the decline visible early.

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

GrowingHQ editorial positionmoderate confidence

As thyme, with the additional note that the variegation which makes it worth buying fades fastest in the low light a system usually supplies.

  • GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

Worth stating because variegated herbs are the ones most often sold for indoor systems, and they are the ones that show poor light first.

Techniques that suit it

  • 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.
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Root space
Small, free-draining.
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

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

  • When it is readyPick soft leafy sprigs at any point in the growing season, and most heavily just before it flowers, when the lemon scent is strongest. New growth carries far more scent than old, so a plant kept trimmed gives better material than one left to go woody.
  • How to pick itSnip sprigs with scissors from green growth only; never cut into bare wood, which will not reshoot. Dries well.
Where the harvest guidance comes from
When it is readySourced guidancehigh confidence
  • Royal Horticultural Society: Thymus — harvesting

Checked 2026-08-13

How to pick itHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

What goes wrong

ProblemHow oftenNotes
Rosemary beetlecommon
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Shake the bush over paper in autumn — the beetles drop rather than fly.
Root rotcommon
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Sources for this page

GrowingHQ editorial synthesis · Plant Finder · Royal Horticultural Society

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-15.