If you’re approaching your first winter as a Peace Lily owner, you might be worried about your plant. Will it survive as the air gets colder? Is there anything you can do to help it stay healthy during the darkest part of the year? Here’s our complete guide to keeping a Peace Lily healthy through the winter.
Peace Lilies are perennials that can survive year-round. However, you should keep them inside for the winter if temperatures drop below 40 degrees where you live. Don’t give your Peace Lily any fertilizer during the winter, and keep it away from drafts and heaters. It will do best between 65°F and 85°F.
During the summer, you can place your Peace Lily’s pot outdoors, as long as you take some basic precautions. We’ll explain how to do this below. And we’ll offer some specific tips on helping your Peace Lily survive the winter. By the time you finish this article, you’ll know how to keep your plant snug and happy even as the snow flies outside.
Are Peace Lilies Sensitive to Cold?
The Peace Lily, or Spathiphyllum, comes from the steamy rainforests of South America. Evolution hasn’t given these plants much protection against chilly weather. Temperatures below 40 degrees Fahrenheit will shock their systems and cause wilting, rotting leaves.
Even temperatures as mild as 55 degrees can set back a Peace Lily’s development. The ideal range for this plant’s health is from 65 to 85 degrees Fahrenheit.
Your Peace Lily can’t survive the winter outdoors unless you’re in a very warm climate. A Spathiphyllum can live as a garden plant in USDA hardiness zones 10-12. In the continental US, that limits outdoor Peace Lily growth to the southernmost parts of Florida, Texas, and California.
A few Peace Lily hybrids are more resistant to mild cold. The cultivars “Annie”, “Debbie”, “Little Angel”, and “Vicount” can bounce back from light frost damage more easily than their cousins. But this doesn’t mean you should treat them as winter-hardy plants. They still prefer the same temperature range as other Peace Lilies – they’re just more likely to survive if you slip up.
Cold Damage in Peace Lilies
A mild chill may have no effect on your Peace Lily beyond stunting its growth for a few months. But if it falls to 40 or below, even for a few hours, you’re likely to see worse damage. Cold shock turns the leaves black and limp. This usually starts at the edges but can spread to cover entire leaves. If you poke your Peace Lily, you may feel squishy spots where the cells have died and started to decay.
Signs of shock may not be visible until 3-5 days after your Peace Lily’s exposure to the cold. If you accidentally leave your plant in a chilly spot, assume it’s hurt until you know otherwise.
Frost damage symptoms can look a lot like a case of root rot. The two conditions can even be related – severe enough cold shock may reach the roots, turning them necrotic. If you notice mushy spots at the crown (the spot where your plant meets the soil) or a foul smell coming from the pot, uproot your Peace Lily and check the roots. This post explains how you can tell if your plant has root rot, and how to treat and prevent it.
How to Fix a Cold-Damaged Peace Lily
The most important thing to do for a cold-shocked Peace Lily is to get it back to a comfortable temperature. That does not mean you should get it hot. Warming your Peace Lily by the fireside or blasting it with a hairdryer will only stress it out more. Just place it in a location within its preferred range of 65-85°F.
Trim off the leaves if they’re completely black and dead. Do the same for any spots that feel soggy and squishy. They’re rotting, and the microbes inside can spread to healthy tissue. Use a sharp pair of pruning shears, disinfecting them first with a 10% bleach solution or some rubbing alcohol. When removing a leaf, cut off the entire stem connecting it to the plant. Slice through at a 45-degree angle, making the cut as quick and clean as possible.
If any of the leaves are only partially damaged, you can leave them alone. The green parts are still absorbing sunlight to feed your Peace Lily. Never prune more than ⅓ of the foliage at a time unless you do so as a last resort because it’s totally dead and decaying.
While your Peace Lily is getting back on its feet, keep it away from any and all direct sunlight. And you shouldn’t apply any fertilizer for a while. Wait until your plant is happily producing new leaves and flowers again.
Can a Peace Lily Survive Winter?
Despite how much Spathiphyllum plants hate the cold, they’re perfectly capable of living through the winter indoors. We doubt you need us to persuade you to keep your home above 60 degrees! Your Peace Lily’s growth will slow down or stop as the days get shorter, but it shouldn’t die back.
You should cooperate with your Peace Lily’s reduced growth rate. Avoid adding any fertilizer during the winter. When your plant doesn’t have enough sunlight to grow, it can’t process those nutrients. The minerals will build up in the potting mix, potentially causing root damage.
Be careful about overwatering, too. The soil takes a lot longer to dry out when the air is cold and the plant is growing slowly. That means there’s a greater risk of letting the pot get soggy and causing root rot. Always wait until the topmost inch or two of soil is dry before watering.
Remember that even if most of your house is warm during the winter, there may be pockets of cold. Don’t let your Peace Lily sit by a drafty window or a door to the outside. Avoid strong heat sources too – the air from a heating vent or a fireplace could scorch your plant. Anything above 90 degrees is too hot for a Peace Lily.
Can I Put My Peace Lily Outside in the Summer?
Though your Peace Lily can’t survive outdoors all year, it will still appreciate a little summer vacation. Placing a Spathiphyllum on your balcony or in your garden during the warm season is great for its growth.
Choose a location where your Peace Lily will be in the shade for most of the day. It can develop burns if sunlight falls directly on its leaves for more than a couple of hours a day. Morning is the safest time to let your plant get a bit of direct sun. Try to make sure it’s in the shadows by 10 AM.
Luckily, even a shady spot outdoors will receive more indirect light than a bright room inside. The extra illumination will help your Peace Lily grow and flower more vigorously.
The best kind of shade for your Peace Lily comes from trees or taller potted plants. This will produce dappled lighting similar to the rainforests where Spathiphyllum plants grow wild. If that’s not an option, shield your plant with an umbrella, a balcony roof, or whatever you have available.
Start moving your Peace Lily outside for an hour or two a day as soon as daytime temperatures get above 60°F. Then start increasing its outdoor time. Within a week or two, your plant should be able to withstand a full day in the open air. You can leave it out full-time once the thermometer is no longer dipping below 55°F at night.
Move your Peace Lily back indoors in the fall. Mid-September is usually a safe bet, but the exact timing will vary depending on your region. If you can no longer count on the temperature staying warmer than 55 degrees, it’s time to bring your Peace Lily back to shelter.
Peace Lilies don’t stand up to the cold very well, but they can manage a winter indoors with little trouble. All they need is the right location and a little moderation with their water and fertilizer. And once summer comes, they’ll be happy to move outdoors. Use the simple tips in this article to keep your Peace Lily healthy all year long.