Spathiphyllum aka Peace Lily

Peace lilies typically grow 1 to 4 feet tall and wide as houseplants, though some cultivars can reach as much as 6 feet (about 1.83 m) tall and wide in ideal conditions. Leaves are elliptical to lanceolate and can range from 4 to 25 inches long and 1 to 10 inches wide. Indoors, plants more commonly settle around 3 feet high and wide.

Peace lilies prefer warm, stable conditions, growing best between about 68–90°F (21–32°C) during the day, with nighttime temperatures no more than 10°F cooler. Temperatures below 60°F can stress the plant, and exposure below 40°F causes cold damage.

The flowers are lightly fragrant.

The peace lily's flower is a single white or greenish-white spathe, 4 to 12 inches (10–30 cm) long, that curls around a greenish-white to cream-colored spadix. All the flowers on a given spadix mature together and release pollen for up to four days.

Popular Spathiphyllum cultivars include 'Mauna Loa' (winner of the Royal Horticultural Society's Award of Garden Merit) and 'Mauna Loa Supreme', 'Sensation', 'Domino', 'Little Angel', 'Allison', 'Jetty', 'Starlight', and 'Wallisii', along with the hybrid Spathiphyllum × clevelandii. Cultivars vary widely in mature size and leaf variegation.

In hot, humid, frost-free climates — roughly USDA hardiness zones 11a to 12b — peace lilies can be grown outdoors as landscape plants, tolerating outdoor conditions well in the right environment.

Repot a peace lily once its roots start growing through the drainage holes or circling on top of the soil surface. Move up to a container only one to two inches larger than the current pot to avoid oversized soil volumes staying too wet.

Wipe the leaves regularly with a damp cloth to keep the foliage clean and dust-free.

Peace lilies are commercially propagated by tissue culture, with young plants potted up through progressively larger containers. At home, the most practical method is division of the clumping rootball when repotting.

Yellowing leaves are most often caused by excessive drying — letting the plant go too long without water.

Brown leaf tips and edges can result from excessive direct sunlight, underwatering, or low humidity, as well as from over-fertilizing (which can burn leaf tips and roots).

Drooping or wilting foliage is typically a sign of excessive drying between waterings.

Stunted or slow growth can be caused by magnesium deficiency in the soil.

Common indoor pests include mealybugs (the most frequent problem), fungus gnats, spider mites, scales, and purple mite. Fungal issues such as Botrytis cinerea, Myrothecium roridum, and Alternaria alternata can cause leaf rot, while root and stem diseases are most often linked to overwatering.

All the flowers on a single spadix mature at the same time and remain receptive, producing pollen for up to four days.

Peace lilies should be treated as inedible: all parts contain insoluble calcium oxalate crystals that cause burning of the mouth, throat, and tongue, drooling, vomiting, and difficulty swallowing if chewed or eaten. One narrow exception is documented in the botanical literature — the young spadix of a single species, S. matudae, is traditionally pickled in vinegar or cooked with eggs in parts of its native range. That is a species-specific traditional preparation, not a general indication that peace lilies are safe to eat.

Beyond ornamental use as a houseplant, peace lilies are commonly cited as one of the top air-purifying indoor plants.