Native to the rainforests of South America, peace lilies (Spathiphyllum) are not true lilies. They are in the Araceae (Arum) family, along with philodendrons, alocasia, and dieffenbachia. Spathiphyllums are easily recognized by their flower structure – a spath surrounding a spadix held above deep green arrow-shaped leaves.
Their common name most likely comes from the white spath, reminiscent of the white flag of surrender.
Spathiphyllums are easy to care for and one makes a perfect plant if you are just starting your houseplant collection. They are also good at cleaning the air, neutralizing carbon monoxide and formaldehyde.
In the United States, spathiphyllums are only hardy in USDA zones 10 and 11. This plant is mostly used indoors, where it brightens homes, restaurants, and offices.
They can be brought outside for the summer, as long as the temperature range is between 65°F to 86°F (18°C to 30°C). They will die if temperatures dip below 50°F (10°C), so protect them from winter drafts indoors.
Grow peace lilies in bright, indirect light. This is the light you’ll find in an east or north facing window. Peace lilies can be grown in low light, but flowering will be reduced.
If grown in too much sunlight, the leaves can scorch and burn. Keep them away from south and west facing windows, and if growing outside, grow them in full shade.
Peace lilies really like moist soil. They will wilt dramatically if they are too dry, letting you know they need to be watered right away. They will recover quickly, usually within a few hours of a good watering.
Usually the more common mistake is to overwater the plant. Make sure you aim for the balance between overwatering and underwatering. If you are worried about making a mistake, it is always better to underwater.
Use a high quality potting mix for your peace lily. If the soil is not well-draining, root rot can develop. Be sure your spath is planted in a pot with drainage holes.
Fertilizing Your Peace Lily
Spathiphyllums don’t need a lot of fertilizer. You can use an all-purpose houseplant food every other month during spring and summer while the plant is actively growing and flowering. Suspend fertilization in fall and winter while the plant is resting. Alternatively, you can apply one application of a slow release fertilizer in the spring.
Keep Your Peace Lily Looking Beautiful
After proper siting, watering, and fertilizing, there are still a few small tasks you need to do occasionally to keep your spathiphyllum looking its best. These tasks include deadheading and cleaning the leaves.
After the spadix has matured, it and the spath turn brown. Cut these off at the base of the stem. Occasionally, a leaf will turn yellow. This is normal as leaves age and the spathiphyllum doesn’t need it anymore. Cut these leaves off at the base, too.
Sometimes the spadix drops pollen on the leaves, and it’s really noticeable against the dark green of the foliage. These large leaves can also get dusty. Use a soft cloth dampened with lukewarm water and gently wipe each leaf. Alternatively, you can take your plant to the kitchen sink and give it a shower.
Peace lilies grow slowly, so they only will need repotting every three years or so. You can tell that your plant needs to be repotted if roots are growing out of the drainage holes, or if it wilts more quickly after watering than it did before.
When you repot, it’s also a great time to divide your spath. Division, a form of propagation, will give you more plants for your collection, or to share with friends and family.
See our articles here and here for more information about repotting peace lilies and about propagating them.
Peace Lily Problems
These plants aren’t generally troubled by insect and disease problems, which is another reason why they make such great houseplants. Some plant problems are caused by improper care and are easily corrected.
Lack of Flowers
“Why isn’t my peace lily flowering?” you might ask. You could be keeping your plant in too dark a location. It could be the wrong season. Spathiphyllums bloom in spring and summer.
Some growers force young spathiphyllums into bloom for better sales; your plant might have been treated with a fertilizer containing gibberellic acid, a hormone that encourages flowering. When that hormone is used up, flowering ceases. Most spaths take a few years to reach maturity and reliable blooming.
Insect problems are rare with spathiphyllums. All the same, you should be on the lookout for spider mites and mealybug when tending your plant. Both these insect pests suck the juices out of plant leaves which creates a mottled appearance to the leaf surface. Spider mites are very small and build fine webs. If you suspect spider mites, shake a leaf over a white piece of paper. The mites will appear as tiny, moving red dots.
Mealybugs are a bit bigger. They are white and fuzzy looking (pollen grains can be mistaken for mealybug!). They tend to hide in leaf whorls and crotches and on the underside of the leaves.
These pests can be controlled with insecticidal soaps.
As mentioned earlier, root rot can be a problem if the soil is not well draining. Be sure to use a lightweight potting mix in a pot with drainage holes.
Spathiphyllum leaves can develop brown tips for a few different reasons. The most common is inconsistent watering, followed by overfertilization. spaths can also develop brown leaves if they are placed in a location that’s too sunny.
An occasional yellow leaf is not cause for concern; all plants shed leaves now and then. A lot of yellow leaves are indicative of watering.
See our article here for more information on peace lily problems.
A word of caution: Spathiphyllums are mildly toxic and can cause stomach upset if any parts of the plant are eaten. If eaten in large amounts, they are poisonous to dogs and cats. Keep this plant away from pets and small children.