Peace lily care: light, water and getting it to flower
A peace lily grows well in bright indirect light and warm room temperatures, watered once the top of the compost has dried. It droops when thirsty and stands up again after a drink, so it is clear when it needs water. This page covers where to put it, brown tips, flowering, which variety to buy and pet safety.
- Bright indirect light for flowers. It survives in shade but rarely flowers there.
- Water once the top few centimetres are dry, with rainwater or filtered water if you can.
- Toxic to cats and dogs on the ASPCA listing, though it is not a true lily.
What a peace lily is, and why it is not a lily
A peace lily is an evergreen perennial in the arum family, the same family as anthuriums and callas. The RHS gives its home as the tropical forests of Central America and Colombia, and NC State widens the genus to Mexico, tropical America, Malesia and islands of the western Pacific. Clemson counts over 40 species and NC State about 60. The one most widely sold is Spathiphyllum wallisii.
The white "flower" is a spathe, a modified leaf wrapped around a spike called the spadix, which carries the tiny true flowers. The RHS says the spathes look like white flags, which is where the common name comes from. Coming from tropical forests explains most of its care: the RHS says it needs warmth, indirect or filtered light, moderate humidity and regular watering while it grows. The plant care guide has the light and water for every other species on the site.
Peace lily varieties and which size to buy
Varieties differ mostly in size, from dwarf plants around 30 cm to ones taller than a person, so choose by the space before the look. Clemson puts most peace lilies at 30 cm to 1.2 m tall and wide, with a few cultivars reaching 1.8 m. A compact one suits a shelf, a desk or a wall pocket. A large one needs floor space and a big pot.
A few cultivars carry white streaks or splashes in the leaf, and like any variegated plant they hold that pattern best in good light. The rest are plain dark green, and choosing between them comes down to height and how freely they flower.
| Variety | Size and leaf | Light it needs | Suits a pocket? |
|---|
| Spathiphyllum wallisii | The common one. Compact, 30 to 38 cm, rippled leaves | Bright indirect for flowers | Yes |
| Spathiphyllum ‘Little Angel’ | Dwarf, 30 to 38 cm, flowers more freely than older kinds | Bright indirect | Yes |
| Spathiphyllum ‘Starlight’ | Dwarf, 30 to 45 cm, tough shiny leaves | Bright indirect, copes with less | Yes |
| Spathiphyllum ‘Gemini’ | Compact, about 30 cm, irregular white splashes | Bright indirect, to hold the splashes | Yes |
| Spathiphyllum ‘Chopin’ | Up to 50 cm, slender white spathes | Bright indirect | Yes |
| Spathiphyllum ‘Bellini’ | Up to 50 cm, widely sold | Bright indirect | Yes |
| Spathiphyllum ‘Jetty’ | 48 to 60 cm, glossy leaves, long-lasting flowers | Bright indirect | Yes, at the top of the range |
| Spathiphyllum ‘Domino’ | About 75 cm, ruffled leaves streaked with white | Bright indirect, to hold the streaks | No, it grows too wide |
| Spathiphyllum ‘Mauna Loa’ | About 90 cm, spathes up to 10 cm long | Bright indirect | No, it needs a floor pot |
| Spathiphyllum ‘Sensation’ | The largest sold, up to 1.8 m, ribbed leaves | Copes with shade | No |
Where to put a peace lily in the house
Put it near a window where the light is bright but the sun does not land on the leaves. The RHS says bright indirect light gives strong growth and flowering, and that plants in deeper shade survive but rarely flower and grow very slowly. Clemson agrees on bright indirect light and adds that direct sun scorches the foliage. NC State lists it for partial to deep shade, which is where the "low light plant" reputation comes from: it tolerates shade, it just does not flower much there. Plants for a low light room compares what else takes a dark spot.
Keep it warm and out of draughts. The RHS gives 12 to 24°C as fine, while Clemson and NC State both prefer 20 to 29°C by day with a drop of about 5°C at night. NC State says cold draughts between 4 and 15°C slow growth considerably and long spells below 4°C damage the leaves and roots. Clemson warns against heating or air-conditioning vents blowing on it, and the RHS against hot radiators.
Turn the pot a quarter each time you water, the RHS suggests, or the plant leans toward the window and grows lopsided.
How often to water a peace lily, and why it droops
Water once the top few centimetres of compost have dried, which is the RHS test. Clemson says the same in other words: keep the soil moist but not soggy and let it dry out slightly between waterings. How long that takes depends on the room. Missouri Botanical Garden lists light, temperature, vents, humidity and distance from a window as what sets the pace, which is why a fixed day of the week does not work.
A peace lily droops when it is dry. The RHS says lack of water can make a peace lily droop alarmingly, and that it should soon recover with no ill-effects if you water it promptly. Do not wait for the droop every time, though. Clemson says that if the soil dries out too far the leaves and edges turn yellow, and Missouri Botanical Garden notes that a plant left too dry can seem to recover after a drink and decline later, because some roots died.
Overwatering is the more serious mistake. The RHS says compost kept too wet leads to root rot and can brown or yellow the leaves, and Clemson names root and stem diseases from overwatering as the most common problem. Never leave the pot standing in a saucer of water. What yellow leaves are telling you sorts out which of the two you are looking at.
The water itself matters. The RHS says the fluoride in tap water can damage the foliage and recommends rainwater or filtered water, and Clemson prefers water at room temperature. NC State adds that watering from below works very well for this plant: stand the pot in water, let it drink, then let it drain.
Why peace lily leaves turn brown, and what to do about it
Brown tips and edges have several causes, and each source names different ones, so check them in order. The RHS names fluoride in tap water and dry air. Clemson names overfeeding and letting the compost dry out too far. NC State names direct sun, underwatering and low humidity, and adds that salt build-up from fertiliser burns the tips and roots.
Start with the cheapest fix. Switch to rainwater or filtered water and move the plant out of any direct sun. If it has been fed often, flush the compost with plain water, as NC State recommends between feeds. If the air is dry from heating, the RHS stands the pot on a tray of damp gravel and mists or wipes the leaves. New leaves coming through clean show the fix worked.
How to get a peace lily to flower
More light is usually the answer. Clemson says a lack of flowers usually comes from too little light or a plant under a year old, and the RHS says the same about light. Move it closer to a window, still out of direct summer sun. NC State says the plant has no fixed bloom time and flowers freely once it is happy, and the RHS says the spathes come mainly in spring and summer.
The flowers change as they age. The RHS says each spathe lasts several months before fading to green. NC State says they turn pale green after about ten days and stay attractive for at least a month more. Once one browns, the RHS snips it off at the base of the stem, and does the same with fading leaves. Wear gloves, because the sap can irritate skin. Indoor plants that flower again covers what else reblooms on a windowsill.
Compost, feeding and repotting a peace lily
Use a free-draining compost. The RHS mixes peat-free multi-purpose compost with perlite at about three to one, and NC State asks for a mix high in organic matter. Clemson says the plant flourishes in almost any well-drained potting mix.
Feed lightly. The RHS gives a general liquid fertiliser every few weeks from April to October. Clemson feeds every six to eight weeks in spring and summer at a quarter of the recommended strength, and says overfeeding burns the leaf tips and roots brown. NC State also uses a quarter strength and flushes the soil with plain water between feeds. Start with Clemson’s lighter hand, and feed only while the plant is growing.
It likes to be a little pot-bound. Clemson repots when roots come through the drainage holes or circle on the surface, into a pot only 2.5 to 5 cm wider, because a much larger pot stays wet and rots the roots. The RHS keeps a new plant in its pot for a year or two and repots in spring. A compost that dries out very soon after watering is the RHS’s sign that it needs a bigger pot.
Is a peace lily toxic to cats and dogs
Yes. The ASPCA lists the peace lily as toxic to dogs and cats, with insoluble calcium oxalates as the toxic principle, and names oral irritation, intense burning of the mouth, tongue and lips, drooling, vomiting and difficulty swallowing among the signs. Clemson adds that it can affect children the same way, and the RHS says to wear gloves when handling it and keep it out of reach of children and pets.
It is not a true lily, and that difference matters for cats. The ASPCA lists true lilies as toxic to cats with kidney failure among the signs, which a peace lily does not cause. It is still toxic, so the answer is the same: out of reach. If an animal in the house eats plants, a calathea wants the same shade and filtered water and the ASPCA lists it as non-toxic to cats and dogs.
A peace lily on the wall
A peace lily grows upright rather than trailing, so on a wall it gives height and broad leaves with the white spathes held above them. Pick a compact variety from the table. The Medium pocket holds 1.8 litres of substrate, about what a 15 cm pot takes, which suits the compact varieties rather than the large ones. Living wall systems, compared covers the other ways to put plants on a wall.
A pocket stands proud of the wall with air on every side, so the substrate dries from more directions than a pot on a shelf does. A peace lily droops when it dries out, so it will show you sooner on a wall than in a pot. Check the substrate with a finger rather than waiting for that, and hang the board beside a window rather than above a radiator.
The board hangs by a slot near its top on one wall hook, so the wall side is one screw, one plug and one drilled hole. Treat the filled weight like a heavy framed picture: plasterboard takes an expanding plug, brick a standard one, and a tiled wall needs a tile bit before the masonry bit. The mounting guide goes through it step by step.
- Fill the pocket a third full with free-draining peat-free compost.
- Slide the plant out of its nursery pot and loosen the root ball gently.
- Set it centred and upright with the crown level with the surface, then top up and firm.
- Water slowly, with rainwater or filtered water, until the substrate is evenly damp.
Peace lily problems and how to fix them
| What you see | Why | The fix |
|---|
| The whole plant droops at once | The compost has dried out | Water it through now, and check with a finger sooner next time. |
| Brown leaf tips and edges | Tap water, dry air, direct sun or too much feed | Switch to rainwater, move it out of sun and flush the compost. |
| Yellow leaves and a wet, heavy pot | Overwatering, heading for root rot | Empty the saucer and let the top few centimetres dry before watering. |
| Healthy leaves but no flowers | Too little light, or a plant under a year old | Move it nearer a window, out of direct sun, and give it time. |
| Yellow between the veins, green veins | Magnesium deficiency, which Clemson names | Feed at a quarter strength with a fertiliser that lists magnesium. |
| White cottony specks under the leaves | Mealybugs, the commonest pest indoors | Wipe the leaves with a damp cloth and check weekly. |
How to divide a peace lily
Division is the way to propagate it. The RHS calls it the easiest method: split a large, established clump into smaller plants in spring. It is also how you rescue a plant that has outgrown its pot.
- Put gloves on, because the sap can irritate skin.
- Take the plant out of its pot.
- Pull or cut the root ball apart into clumps, each with plenty of roots and several strong stems.
- Pot each clump in free-draining peat-free compost, in a pot only a little larger than its roots.
- Water it in and keep it out of direct sun while it settles.
Does a peace lily clean the air?
Not measurably in a real room. The RHS and Clemson both repeat the air-purifying claim, but the figures behind it come from sealed test chambers, and the air exchange in an ordinary house swamps anything a few pots do. Grow it for the leaves and the flowers.
Can a peace lily live in a bathroom?
Yes, if the bathroom has a window. The RHS says peace lilies prefer moderate humidity and brown at the edges in dry air, so a bathroom helps the leaves. Without daylight it will survive and stop flowering.
Can a peace lily go outside?
In summer, in shade, and only while the nights stay warm. NC State says temperatures between 4 and 15°C slow it considerably and long spells below 4°C damage it, and Clemson says to avoid anything below 15°C. Bring it in before the nights cool.
Should I cut the brown tips off a peace lily?
You can, and it is only cosmetic. A brown tip never turns green again, so cut along the brown edge with clean scissors, following the leaf’s shape. The tips stop browning only once you fix the cause.
How big does a peace lily get?
It depends on the variety. Clemson puts most at 30 cm to 1.2 m tall and wide, and NC State says they typically reach about 90 cm indoors. The dwarf kinds stay near 30 cm.
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