Disclosure: Amazon links on this page are affiliate links, so this site may earn a commission at no extra cost to you. Commissions don’t decide which products are recommended. See the full affiliate disclosure.
Peace lily is the houseplant most often confused with a lily — and the confusion matters. Spathiphyllum is in the aroid family (Araceae), completely unrelated to true lilies (Lilium), which are acutely nephrotoxic to cats. Peace lily is toxic too — but by calcium oxalate crystal irritation, not kidney failure. Different mechanism, different risk profile, different urgency. The other thing to know: it's one of the few houseplants that tolerates genuinely low light.
What it is
Spathiphyllum is a genus of about 76 accepted species per Kew POWO. The plants sold in stores are usually hybrids labeled as the genus — Spathiphyllum spp. — rather than a specific species. The most common parent is Spathiphyllum wallisii (native Colombia to Venezuela), per Kew POWO.
Native habitat: tropical forests from Mexico through tropical America, plus Southeast Asia and the western Pacific, per Kew POWO. The plants grow on the forest floor, per Missouri Botanical Garden.
How it compares with another white-spathed aroid: anthurium vs. peace lily.
Light
Part shade to full shade. Peace lily tolerates genuinely low light better than almost any other flowering houseplant. NC State Extension lists the acceptable light range as partial to deep shade — with deep shade defined as less than 2 hours of direct sunlight per day. MBG specifies that the plants do well in lower light situations but prefer bright filtered light, and explicitly states: do not place in direct sun.
In practical terms, a north-facing window is fully acceptable — Clemson HGIC calls peace lily one of the few foliage plants that will flower in low light. An east window or a spot set back from a south or west window works well. Direct afternoon sun through glass scorches the large, thin leaves, producing brown patches that won't recover.
Signs of too much light: brown scorch patches on the leaf surface (not confined to the tips), yellowing across broad sections of the leaf, bleached or faded coloration. Signs of too little light: slow growth, no new flowers, and increasingly narrow, elongated leaves stretching toward the light source. If your peace lily isn't blooming, Clemson HGIC notes the usual causes are insufficient light or a plant less than a year old. MBG notes peace lilies tolerate lower light but prefer bright filtered light.
Watering
Keep the soil evenly moist but not soggy. NC State Extension states: "keep the soil moist, but not soggy; allow it to dry between waterings." MBG is consistent: "best grown in evenly moist but not soggy soil — let the soil dry between waterings, but do not allow to wilt."
The peace lily's dramatic droop — leaves folding and hanging — is a reliable thirst signal, but MBG advises not letting the plant wilt, so it's better to water before it droops; repeatedly wilting to the point of droop stresses roots over time.
MBG recommends using water at room temperature that has been allowed to sit so chlorine can evaporate. Bottom-watering (sub-irrigation) works very well — NC State explicitly states "watering from below works very well for peace lilies." Set the pot in a few inches of water, remove it when moisture has wicked up through the soil and shows at the top, then drain completely (per University of Illinois Extension).
The chlorine-off-gassing recommendation from MBG is worth following. Overwatering symptoms: yellow leaves from the base upward, soft stems at soil level, soil that stays wet — likely root rot. Underwatering symptoms: dramatic full-plant droop, brown tips that appear dry rather than waterlogged, and very dry soil pulling away from the pot edges.
Soil and pH
Potting mix high in organic matter. NC State Extension lists the preferred soil pH as acidic, below 6.0. MBG notes the plant requires a large pot and should be kept somewhat potbound — do not rush to upsize the container. Repot in February or March if the plant is root-bound or the soil has degraded, per MBG.
A standard peat-based potting mix with good drainage serves well. The slightly acidic pH of peat-based mixes is naturally compatible with the species' requirements. Avoid dense, low-porosity mixes — NC State calls for good drainage, so aeration in the mix matters.
Plastic or glazed ceramic pots retain moisture better than terracotta, which is generally appropriate given the plant's consistent moisture preference. Terracotta can work in humid climates or in rooms with naturally higher humidity.
For watering consistency, a soil moisture meter is useful — peace lily roots want to stay evenly moist, and guessing causes both overwatering and underwatering problems.
Humidity
Peace lily tolerates average indoor humidity better than many aroids. Brown leaf tips caused by low humidity are one diagnostic symptom, per NC State, but the same symptom also results from excessive direct sunlight and underwatering, so diagnose carefully before adding a humidifier.
If the plant's tips are browning and watering and light are already correct, a pebble tray under the pot or placement near a kitchen or bathroom will provide modest ambient humidity without additional equipment. Misting is not recommended — it does not meaningfully raise ambient humidity and can leave water droplets on the glossy leaves that mark the surface.
Temperature
Daytime 68–85°F (20–29°C), with a drop of up to 10°F at night acceptable, per NC State Extension. Between 55°F and 40°F growth slows considerably, and extended periods below 40°F damage leaves, stems, and roots, per MBG. Avoid cold drafts.
Pet safety: not a true lily
The ASPCA classifies peace lily as toxic to dogs and toxic to cats. The toxic principle is insoluble calcium oxalates — needle-like crystals (raphides) that mechanically irritate the mouth, tongue, and throat when chewed.
Symptoms include severe pain in the mouth, burning sensation to lips and tongue, excessive drooling, vomiting, and difficulty swallowing. This is different from true lily toxicity. The FDA explains that eating just a small amount of a true lily (Lilium) or daylily (Hemerocallis) leaf or flower petal can cause fatal kidney failure in a cat, while plants that only have "lily" in their name, such as peace lily, "don't cause kidney failure in cats." The FDA adds that those plants can still cause other serious problems if eaten. If your cat chews a peace lily leaf, call your veterinarian.
More detail, including what to do if a pet chews one: Are peace lilies toxic to cats and dogs?
Common problems
| Symptom | Likely cause | Fix |
|---|---|---|
| Brown leaf tips | Direct sun, underwatering, or low humidity per NC State | Move out of direct sun, water more consistently, place on a pebble tray — see brown leaf tips guide |
| Yellow leaves | Overwatering or aging lower leaves — see yellow leaves guide | Reduce watering frequency; trim aged leaves; check for root rot |
| No flowers | Insufficient light, or too young | Move to brighter indirect light; plants less than a year old often don't flower yet, per Clemson HGIC |
| White crust on soil surface | Salt buildup from over-fertilizing | Flush the pot with water, reduce fertilizer to quarter-strength per MBG |
| White cottony deposits | Mealybugs — the most common pest per NC State | Remove with alcohol swab; treat with neem oil; wipe leaves with damp cloth regularly |
The fertilizer point is worth its own callout. MBG specifically warns that peace lilies have very low fertility needs indoors — apply fertilizer at one-quarter the recommended strength. Over-fertilizing causes tip burn and root burn and is one of the more common misdiagnosed causes of brown tips.
Propagation
Peace lily propagates by division, per NC State Extension. Spring is the ideal time, per the RHS — February or March repotting is recommended by MBG, which aligns with the plant entering active growth.
To divide: remove the plant from its pot, gently tease apart the root mass into sections, each with healthy leaves and a portion of root. Pot each section into fresh acidic potting mix, water thoroughly, and place out of direct sun while it establishes. Division is also the solution when a mature peace lily has become overcrowded and flowering has slowed.