White flags above dark green leaves: the peace lily flowers indoors too and lets its leaves droop as soon as it's thirsty – a plant can't ask for water any more clearly.

What it does for you

The peace lily is one of the few foliage plants that still flower in fairly low light¹ – in deep shade, though, it rarely flowers². The white "flower" is actually a bract wrapped around a spike of tiny flowers³. And it shows you when it's thirsty: it lets all its leaves droop – water it quickly and it recovers fast².

Origin & history

There are many varieties on sale, from 30 centimetres to over a metre tall³. The one sold most often is Spathiphyllum wallisii² – and that's the species this page is about. The sizes on the fact sheet are those of typical shop plants and larger cultivars; the pure species stays at about 30–40 cm^1,6. In the wild it grows in Colombia and Venezuela⁷. The genus lives in the understorey of humid rainforests in Central and South America, a few species also in South-East Asia³.

The name "peace lily" comes from the bracts, which look like white flags². It isn't a true lily, though, but a member of the arum family¹.

Caution

The peace lily contains calcium oxalate crystals. Chewing on it causes severe pain and burning in the lips, tongue and throat⁶. Cats and dogs drool, vomit and have trouble swallowing⁸. So keep it out of reach of children and pets. NC State lists no contact dermatitis⁶, but the RHS warns that the sap can irritate the skin² – wear gloves when cutting.

Care

Light. Ideally bright without direct sun, which burns the leaves. It tolerates low light¹, but then grows slowly and hardly flowers².

Water. Water as soon as the top centimetres of soil are dry, less in winter² – as a rule of thumb about once a week in summer. Never leave it standing in water, or the roots rot¹. If it droops, a thorough watering helps within hours. If that happens often, the leaf edges turn brown³.

Temperature & humidity. Normal room temperature suits it: the RHS names 12–24 °C², Clemson up to about 29 °C by day; below about 15 °C it risks cold damage¹. Don't put it next to a radiator or in a draught. If the air is too dry, the leaf edges turn brown – a tray of damp gravel helps².

Soil, pot & repotting. Peat-free houseplant soil with some perlite². Repot in spring once roots fill the pot; freshly bought plants only after one to two years². The new pot should be only slightly bigger than the root ball, otherwise the soil stays wet for too long¹.

Feeding. From spring to mid-autumn every few weeks², as a rule of thumb about monthly at most and at weak strength; Clemson even advises only every 6–8 weeks at quarter strength¹. Too much fertiliser burns leaf tips and roots³.

Extras

Left to itself, the peace lily flowers mainly in spring and summer. The bracts last a long time and turn green with age². Young plants under a year old often don't flower yet¹. Nurseries often make it flower with the plant hormone gibberellin – at any time of year³.