This article by Fleuriste Atropa Belladonna, a Montreal florist, explains how to care for Peace Lily (spathiphyllum), from soil and fertiliser, to light and watering, humidity and troubleshooting.
Spathiphyllum, Also Known as Peace lily, Spathe, and White Sail
A beautiful plant native to the tropical areas of the Americas as well as Southern Asia. It is one of the recommended indoor plants, by NASA, for air purification; why? Because it’s better at breaking down and neutralising toxic gases like benzene, formaldehyde, and carbon monoxide. This is not to say that other plant’s don’t purify the air or give us oxygen, these are simply more efficient. Plant choice is always dependant on your living/office space.
Soil
Soil requirements: All purpose or tropical mix soil. It’s always preferably to be planted in a pot that drains. If you’re displaying it in a non-drain decorative pot, not worries, just keep the plant in it’s planter pot, so that you can get rid of any water that drains into the decorative one.
Fertiliser
A balanced fertilizer is ideal, such as a 5-5-5 or 10-10-10. Peace lilies don’t require a lot of feeding, how much will depend on the kind of fertilizer you are using; but if it is water soluble feeding it once every three months should be fine, where as slow release fertilizers can be applied less often, twice a year during fall and Spring
Sun/Lighting
Bright indirect light, here in Montreal they can take the morning sunlight (anything that hits them before 11am).
Watering
It’s important to keep the soil is ideally kept moist, but not soaking. Water your plant when the soil is somewhat moist (or a medium to light weight), you should feel your plant become heavy. Don’t water if it is wet, saturated, and heavy. I recommend watering your plant over a sink and allowing the water to freely drain away. Never keep you plants sitting in water, though peace lilies are one of the more forgiving plants when it comes to this, it can cause root rot! Add water until it begins to run out of the drain wholes, let it drip dry before replacing it it’s deco. pot or tray.
Humidity & Temperature
Typically Peace lilies prefer not to go below 21 degrees Celsius. They enjoy humidity, so if you can lightly mist them once every few days they will do well. If conditions are already humid, this is not recommended as if can cause molding.
Dead leaves & Flowers
You can trim away yellow or brown leaves. As for browned flowers, you can cut them near where they exit the leaf, the flower stem that is left will eventually dry up all the way down to the base, and you will eventually be able pull it loose from the leaf, but this may take several days or weeks.
Drooping / Yellowing Leaves
Don’t panic, and don’t act before you access the situation. Drooping leaves are probably an indication that your plant is under watered; if you pick it up and it’s very light, you have confirmation, go water your plant!
After being underwatered, some leaves may turn Yellow! Has your plant been under watered lately? Yes, then it’s just natural, and there’s nothing more to do. Do not run to water it again, because likewise yellow leave can be… from over watering! If your plant did not go through a drought, check, is it heavy? Is it drowning in water? Well it’s time to drain the pot – if its been like that for a while, you may have to change the soil.
Dogs & Cats
Spathiphyllum is toxic to both.
Nasa Study
The study with the complete list of recommended plants can be view here as PDF
Likewise, Nasa’s overview of the findings can be found here