GrowingHQ
OrnamentalbulbousSome care needed

Lily

Lilium

Before you grow or eat this

True lilies cause acute kidney failure in CATS, and the dose required is very small — a few petals, a couple of leaves, water from the vase, or pollen groomed off the coat after brushing past. Dogs are not affected in the same way and get only a stomach upset. Without prompt veterinary treatment feline lily poisoning is frequently fatal. Do not grow lilies, or bring cut ones into the house, if you have a cat. If a cat has had any contact at all — including pollen on its fur — treat it as an emergency and ring a vet immediately rather than waiting for signs of illness.

The most imposing summer bulb there is, superb in a large pot, and the most dangerous plant in this catalogue for anybody who owns a cat — every part of a true lily, including the pollen, causes acute kidney failure in cats and a small exposure is enough.

Position
Full sun or Partial shade
Water
moderate demand
Drainage
Free-draining
Grows to
60–180 cm × 20–40 cm
Hardiness
H6
Flowers
June to August
Difficulty
Some care needed

August

In flower

Lily’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
PlantMarch. October. November.
In flowerJune. July. August.

Names that cause confusion

lily — Applied to a great many plants that are not Lilium at all — peace lily, day lily, arum lily, lily of the valley. The distinction matters for cat owners: true lilies cause fatal kidney failure in cats, and most of the others do not.

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.

Conditions it needs

Light
Full sun, Partial shade
Frost
Very hardy
Hardiness rating
H6 (RHS)
Grows best at
12–26 °C
Soil
Loam, Peat-free compost, Sandy
Soil pH
5.5–7
Drainage
Free-draining
Water needs
moderate
Drought
moderate tolerance
Waterlogging
poor tolerance
Heat
moderate tolerance
Wind and exposure
moderate tolerance
Where these figures come from
LightSourced guidancemoderate confidence
  • Royal Horticultural Society: Lily — position

Checked 2026-08-13

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

Checked 2026-08-13

SoilSourced guidancemoderate confidence
  • Royal Horticultural Society: Lily — soil

Checked 2026-08-13

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

Checked 2026-08-13

DrainageSourced guidancemoderate confidence
  • Royal Horticultural Society: Lily — 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

Bulbs rot readily in wet winter ground.

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 conditionLily 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 Lily as it stands: The pH suits it: it wants 5.5 to 7, 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.
Chalky and alkalineWorks, with one conditionLily will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5.The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground.
LoamPrefers this soilLoam suits Lily as it stands: The pH suits it: it wants 5.5 to 7, 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 Lily as it stands: The pH suits it: it wants 5.5 to 7, 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 conditionLily 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 Lily as it stands: The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting.
Made ground and urban soilWorks, with one conditionLily 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
60–180 cm
Mature spread
20–40 cm
Rooting depth
40 cm
Spacing
20–30 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: Lily — spacing

Checked 2026-08-13

How far apart to plant lilyThree lily plants drawn in a row at their recorded spacing of 20–30 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.20–30 cm
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
35 cm
Where the container figures come from
Minimum volumeHorticultural consensusmoderate confidence
  • Royal Horticultural Society: Lilies — cultivation

Checked 2026-08-13

Minimum depthHorticultural consensusmoderate confidence
  • Royal Horticultural Society: Lilies — cultivation

Checked 2026-08-13

Genuinely well suited to a deep pot, and depth is the requirement — most lilies root from the stem above the bulb as well as below it, so they want 15–25 cm of compost over the top and more below. Three bulbs to a 30 cm pot is a good display. Loam-based compost, and stand the pot where you will pass it in the evening, which is when the scented ones are worth the trouble.

Habit and ultimate size

What the plant becomes, rather than what it is when you buy it. The gap between the two is where most planting mistakes live.

In a container
Good in a container long-term
Where these figures come from
In a containerHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Bulb, corm, rhizome and tuber comparedFour underground storage organs drawn in section at the same scale. A true bulb is layered scales around a growing point on a flat basal plate, and multiplies by offsets that pull apart by hand. A corm is a solid swollen stem base with a bud on top, the previous year's spent corm beneath it and small cormlets at its sides. A rhizome is a horizontal swollen stem that sits at soil level with roots below and a growing point at one end, and must not be buried. A tuber is a swollen stem with growth buds scattered over its whole surface and no basal plate, so a cut piece without a bud on it cannot grow.True bulbbasal plateDaffodil, tulip, lilyPull offsets apart by hand.Cormspent corm below, cormlets asideCrocus, gladiolus, crocosmiaReplaced yearly by a new one on top.Rhizomesoil level — top stays exposedBearded irisCut with a knife. Must not be buried.Tuberbuds scattered, no basal plateCyclamen, potatoA cut piece without a bud will rot.
All four are sold as 'bulbs'. The differences are internal, which is why they are drawn rather than photographed — and each one changes what you physically do with the thing in your hand.
Storage organ
True bulb
Survives winter in the ground
Yes — plant once and leave it
Planting depth
15–25 cm
Naturalises
Stays where it is put
Where these figures come from
Storage organSourced guidancehigh confidence
  • Royal Horticultural Society: Lilium — propagation

Checked 2026-08-13

Survives winter in the groundSourced guidancehigh confidence
  • Royal Horticultural Society: Lilium — hardiness

Checked 2026-08-13

Planting depthSourced guidancemoderate confidence
  • Royal Horticultural Society: Lilium — planting depth

Checked 2026-08-13

NaturalisesHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Layered scales around a basal plate — an onion in cross-section. Multiplies by producing offsets alongside the parent, which can be pulled apart by hand when the clump is lifted.

How deep to plant a bulb, drawn to scaleEight geophytes drawn at one scale against a soil surface line, each at the depth the catalogue records for it. A bearded iris rhizome sits on top of the soil with only its roots buried. A cyclamen tuber and a nerine bulb are barely covered, at 2 to 3 centimetres, the nerine with its neck standing proud. Snowdrops and crocuses go at 8 to 10 centimetres, a daffodil at 10 to 15, a tulip at 15 to 20 and a lily deepest at 15 to 25 centimetres. Most sit at roughly two to three times their own height, and the shallow exceptions are shallow because the organ must bake in the sun to flower.soil surface5 cm10 cm15 cm20 cmBearded irison topon the surfaceCyclamen2 cmjust coveredNerine2 cmneck proudSnowdrop9 cmCrocus9 cmDaffodil13 cmTulip18 cmplant deepLily20 cmstem roots
Two to three times the bulb's own height is the working rule, and the four plants that break it are the four most often planted wrong. A bearded iris buried by mulch or a tidy neighbour will make leaves for years and never flower again.
After flowering. Deadhead but leave the stem and leaves standing until they yellow — most lilies root from the stem above the bulb as well as below it, and the stem is feeding next year's flower.
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

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

Traditional dug bedWell 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

Growing it

  • PlantingPlant deep, at about three times the bulb's own height, and on grit if the ground is at all heavy. Most lilies produce roots from the stem above the bulb as well as beneath it, so a shallow planting loses the plant half its root system and the stems blow over.
  • ProtectionCheck the undersides of the leaves for scarlet lily beetle from April onwards and pick the adults and the larvae off by hand. They are unmistakable — bright red beetles, and larvae that cover themselves in their own excrement — and an unwatched plant is skeletonised within a week or two.
  • WateringLilies are in growth right through the summer and do want water, which separates them from most of the bulbs sold beside them. Keep the soil steadily moist while the stems are growing and in bud, and water at the base rather than over the flowers. They will not tolerate standing wet in winter, which is the other half of the same answer: free-draining soil, or a raised position, or a pot. Pots need real attention because a lily in flower is a tall plant on a small root volume and dries fast — check them daily in July. Most lilies root from the stem above the bulb as well as below it, so keeping the top few centimetres of compost moist matters more than it does for other bulbs.
  • FeedingFeed fortnightly with a high-potash liquid feed from the time the shoots are up until about a month after flowering, which is when the bulb is rebuilding for next year. Tomato food is the usual choice and works well. Avoid high-nitrogen feeds — soft growth on a two-metre stem is a plant that needs staking and is more attractive to lily beetle. Deadhead the flowers but leave the stem and leaves standing until they yellow, because that stem is feeding next year's flower and cutting it down in August is a common and expensive tidy-up.
Where this guidance comes from
PlantingSourced guidancehigh confidence
  • Royal Horticultural Society: Lilium — planting depth

Checked 2026-08-13

ProtectionSourced guidancehigh confidence
  • Royal Horticultural Society: Lily beetle

Checked 2026-08-13

WateringSourced guidancehigh confidence
  • Royal Horticultural Society: Lilies — cultivation

Checked 2026-08-13

FeedingSourced guidancehigh confidence
  • Royal Horticultural Society: Lilies — cultivation

Checked 2026-08-13

What goes wrong

ProblemHow oftenNotes
Lily beetlecommon
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Scarlet adults and their camouflaged larvae strip the foliage from March onward.
Congested bulb clumpoccasional
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Safety and edibility

Cats and dogsCan be dangerous — treat as urgentListed at genus level

Listed as harmful to cats or dogs

Lily is listed as harmful if eaten. In CATS an unidentified compound in every part of a true lily — petals, leaves, pollen and vase water — causes acute tubular necrosis of the kidneys. The dose is very small: pollen groomed off the fur after brushing past a flower has been enough, and without veterinary treatment within a few hours the poisoning is frequently fatal. DOGS are affected quite differently and much less severely, getting gastrointestinal upset rather than kidney injury.
source

Sourced guidancehigh confidence

  • ASPCA Animal Poison Control Center — toxic and non-toxic plant list — American Society for the Prevention of Cruelty to Animals: Lilium — toxic plants list
  • Veterinary Poisons Information Service — VPIS, London: Lilium — clinical effects

Checked 2026-08-13

Affected parts: all parts, flower, leaf.

  • Pets and livestockpetsTrue lilies cause acute kidney failure in CATS, and the dose required is very small — a few petals, a couple of leaves, water from the vase, or pollen groomed off the coat after brushing past. Dogs are not affected in the same way and get only a stomach upset. Without prompt veterinary treatment feline lily poisoning is frequently fatal.
    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Lilium — toxicity to cats

    Checked 2026-08-13

    Do not grow lilies, or bring cut ones into the house, if you have a cat. If a cat has had any contact at all — including pollen on its fur — treat it as an emergency and ring a vet immediately rather than waiting for signs of illness.

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 2026-08-14.

If something is wrong with it

Something else? Work through it with the diagnostic tool.