GrowingHQ
Herbperennial herbStraightforward

Hyssop

Hyssopus officinalis

A small Mediterranean sub-shrub used far more as an ornamental and a bee plant than in a kitchen, and honest to say so — the flavour is strong, bitter and used sparingly. As a plant it is thyme's more upright relative: dry, sunny, sharply drained, and killed by a wet winter rather than a cold one.

Position
Full sun
Water
low demand
Drainage
Free-draining
Grows to
45–60 cm × 45–60 cm
Hardiness
H5
Flowers
July to September
Difficulty
Straightforward

August

In flower

Hyssop’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
Sow under coverMarch. April.
PlantMay. June.
In flowerJuly. August. September.
PruneApril.

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: Hyssop — 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, lemon thyme, 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: Hyssop — 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: Hyssop — harvesting

Checked 2026-08-13

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

What it is worth to pollinators

Recorded only where the evidence is specific to this plant, because “good for bees” attached to everything means nothing attached to anything.

Nectar value
high
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Plants for pollinators

Checked 2026-08-13

In flower
July, August, September

Picking it and feeding bees are not the same plan

Very little, because hyssop is picked in small quantities — the flavour is strong enough that a few leaves go a long way, and the plant is grown as much for the flowers as for the kitchen.

Conditions it needs

Light
Full sun
Frost
Hardy
Hardiness rating
H5 (RHS)
Grows best at
12–26 °C
Soil
Sandy, Loam, Chalky
Soil pH
6.5–8
Drainage
Free-draining
Water needs
low
Drought
good tolerance
Waterlogging
poor tolerance
Heat
good tolerance
Wind and exposure
good tolerance
Where these figures come from
LightSourced guidancemoderate confidence
  • Royal Horticultural Society: Hyssop — position

Checked 2026-08-13

FrostSourced guidancehigh confidence
  • Royal Horticultural Society: Hyssop — 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: Hyssop — temperature

Checked 2026-08-13

SoilSourced guidancemoderate confidence
  • Royal Horticultural Society: Hyssop — soil

Checked 2026-08-13

Soil pHSourced guidancemoderate confidence
  • Plant Finder — Missouri Botanical Garden: Hyssopus officinalis — culture

Checked 2026-08-13

DrainageSourced guidancemoderate confidence
  • Royal Horticultural Society: Hyssop — 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

Winter wet is what kills it, as with most of this group.

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 conditionHyssop 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 Hyssop as it stands: 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 Hyssop 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 Hyssop as it stands: The pH suits it: it wants 6.5 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 Hyssop as it stands: The pH suits it: it wants 6.5 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 conditionHyssop 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 Hyssop 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 conditionHyssop 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
45–60 cm
Mature spread
45–60 cm
Rooting depth
35 cm
Spacing
40–50 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: Hyssop — spacing

Checked 2026-08-13

How far apart to plant hyssopThree hyssop plants drawn in a row at their recorded spacing of 40–50 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.40–50 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
10 litres or more
Minimum depth
25 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

Takes to a container well and shows the flowers off at eye level, which is most of the reason to grow it. Deep rather than wide, with sharp drainage, and no feeding.

Value to wildlife

Recorded only where the evidence names a resource and the months it is available. Most plants flower; that on its own is not what this section is about.

Nectar
A significant source
In flower
Jul, Aug, Sep
Where these figures come from
NectarSourced guidancemoderate confidence
  • Royal Horticultural Society: Plants for pollinators

Checked 2026-08-13

What keeping this costs

Very little, because hyssop is picked in small quantities — the flavour is strong enough that a few leaves go a long way, and the plant is grown as much for the flowers as for the kitchen.

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
Open groundWell suited
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

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

10 litres; Gritty free-draining compost
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

A woody sub-shrub with the Mediterranean group's objections, and grown as much for its flowers as its leaves — which need light a system rarely 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

  • PruningTrim lightly to shape in spring once new growth shows, and cut the flowered stems back after they finish. Like most of this family it will not reshoot from bare old wood, so a plant allowed to go leggy cannot be brought back by hard pruning.
  • PropagationTake softwood cuttings in early summer. Seed-raised hyssop is variable in flower colour and vigour, and a plant worth keeping is worth propagating from rather than resowing.
  • WateringWater only while a new plant establishes, then stop. Hyssop is a dry-bank plant with a deep root and it is more likely to be lost to a waterlogged winter than to a summer drought. In a pot, water thoroughly and let it dry out well in between; do not keep it evenly moist.
  • FeedingDo not feed. Hyssop is grown as much for its flowers and the bees they bring as for its strong bitter leaf, and a fed plant makes leaf at the expense of flower and then falls open in the middle. Poor chalky soil gives the best plant.
  • HarvestingPick young shoot tips before the plant flowers if you want the leaf, which is used very sparingly — the flavour is strong and bitter. Most growers take the flowering spikes instead, cutting them as the first florets open, and leave the rest for the bees.
  • PlantingPlant in late spring into full sun and sharp drainage, ideally at the front of a border or on a bank where it can be seen in flower. It resents being moved once settled, so choose the position with that in mind rather than expecting to shift it later.
Where this guidance comes from
PruningSourced guidancemoderate confidence
  • Royal Horticultural Society: Hyssop — pruning

Checked 2026-08-13

PropagationSourced guidancemoderate confidence
  • Royal Horticultural Society: Hyssop — propagation

Checked 2026-08-13

WateringSourced guidancehigh confidence
  • Royal Horticultural Society: Hyssop — cultivation

Checked 2026-08-13

FeedingSourced guidancehigh confidence
  • Royal Horticultural Society: Hyssop — cultivation

Checked 2026-08-13

HarvestingSourced guidancehigh confidence
  • Royal Horticultural Society: Hyssop — uses

Checked 2026-08-13

PlantingSourced guidancehigh confidence
  • Royal Horticultural Society: Hyssop — planting

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. A compact sub-shrub that cuts well in summer on a bright sill and, like the other Mediterranean herbs, resents winter indoors more than winter outdoors.

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

A woody sub-shrub with the Mediterranean group's objections, and grown as much for its flowers as its leaves — which need light a system rarely supplies.

  • GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

Grown as much for bees as for the kitchen, which is a purpose an indoor system cannot serve at all.

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.

What goes wrong

ProblemHow oftenNotes
Root rotoccasional
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.