For most of the year, watering a peace lily once a week is enough to meet its basic moisture needs. In warmer weather, it’ll be happier with more frequent watering – around 2-3 times a week, plus a regular spritz with a misting spray.
But there’s a little more to it than that. Other factors like humidity, pot size and soil type all affect how often a peace lily needs water. So it’s best to take your cues from the plant.
As you’ll know if you have one, peace lilies (Spathiphyllum) aren’t shy to let you know when they need more water. A thirsty peace lily will dramatically droop, though the forgiving plants usually recover quickly after watering.
Though they are resilient, it’s best to avoid underwatering a peace lily if you can. Persistent drought stress will turn the leaves crispy and brown at the tips and edges. If left too dry, for too long, it will kill the plant.
With a humid natural habitat, peace lilies are moisture lovers. Native to Central & South American rainforests, they sit on the forest floor bathed in moisture for much of the year.
They prefer slightly moist soil at all times, with plenty of humidity in their immediate environment. They’re particularly sensitive to the dry air in heated or air conditioned rooms.
Watering them well, adjusting the frequency to suit the season and the situation, is the surest way to keep peace lilies happy.
How much water does a peace lily need?
As mentioned, a once-weekly water is usually enough for your peace lily in autumn and winter; 2-3 times a week in spring and summer. Add a liquid feed to the water every couple of weeks from late spring to autumn.
When you water, don’t hold back. Soak the plant generously until the excess runs out through the drainage holes. That way you know water has reached the root ball.
Discard any water sitting in the saucer or pot cover after a couple of hours to prevent root rot. Mist the foliage once or twice a week to boost humidity, especially in dry conditions.
Dry air can parch the plant and encourage red spider mites. These tiny pests suck the sap, leaving yellow marks which eventually turn brown. Increasing humidity helps to keep them at bay.
Keep in mind that these are general guidelines. Individual watering needs from plant to plant will depend on their specific growing environment.
Variances in pot size/material, soil type, temperature and humidity will affect how often you need to water your peace lily. For optimal plant health, it’s best to be guided by your plant rather than sticking to a rigid watering schedule.
Check soil moisture before watering
To avoid under or overwatering a peace lily, nothing beats close observation of the plant and its soil. The soil should never dry out completely, nor be sodden and squelchy as this can starve roots of oxygen.
Aim to keep soil moist but not wet. You can periodically check soil moisture by pushing in your finger up to your first knuckle. If the top few centimetres of soil feels dry, your peace lily needs water.
Alternatively, use a houseplant soil moisture meter to give you a more accurate reading. These include a probe that goes deeper into the soil, making it easier to see that soil stays evenly moist.
How often to water a peace lily in summer
Though they’re tropical plants with a preference for warmth, peace lilies thrive best in moderately warm rather than hot weather.
A daytime temperature range of around 18-26˚C (65-80˚F) suits them best. They also prefer sitting in semi-shade, rather than the drying heat of direct sun.
In summer, when temperatures regularly exceed 18˚C, peace lilies need more frequent watering due to heavier water loss.
Heat, light and dehydration
Increased heat and light in summer speeds up transpiration by warming the plant’s leaves, making water evaporate more quickly. To replace lost water in summer, a peace lily generally needs watering 2-3 times a week as a minimum.
In hotter climates or particularly dry environments, the plant will dehydrate more quickly and need watering more often. If this applies, you may find you need to water every 1-2 days.
TOP TIP – Keeping your peace lily out of direct sunlight becomes especially important in summer. Semi-shade will make it lose water less quickly, as well as preventing leaves from becoming brown and scorched.
Supplement your summer watering by using a misting spray at least once a week to increase humidity around the plant. Think steamy rainforest!
How often to water a peace lily in winter
A peace lily generally needs watering less often in colder winter weather. Though it doesn’t have a period of dormancy, the drop in temperature means it loses less water through evaporation.
While a peace lily can grow (and even flower) throughout the year in favourable conditions, it grows less vigorously in winter.
The reduced temperature, light intensity and daylight hours makes the plant photosynthesise more slowly. With less metabolic activity, the plant uses less water.
Beware – heated rooms will sap moisture
Bear in mind that indoor heating can muddy the waters a little. If you like to turn the thermostat up high in winter, it will increase the temperature and reduce the humidity around your plant.
Hotter, drier air will dehydrate soil more quickly. If you check the soil daily, you’ll be best placed to know how often your plant needs a top up.
And don’t be reluctant to use your misting spray in winter. It’s pretty well impossible to over-mist a peace lily, so a spray every so often won’t do it any harm.
A little over-zealous misting beats waiting until leaves get brown crispy edges and papery spots!
What else affects a peace lily’s need for water?
As significant as the season is, it’s not the only factor that dictates how often to water a peace lily. The growing medium, pot and location of your plant will all affect it to a greater or lesser degree.
It’s worth taking these into account as well as the time of year:
Size of the pot
When potting a peace lily, it’s generally recommended to choose a pot up to one third bigger than the root ball.
If your pot is on the smaller side, it will hold less water and soil will dry out more quickly. This isn’t necessarily a problem, as long as you water regularly and your plant looks healthy.
But recurrent drooping, despite regular watering, is a clear sign a peace lily has outgrown its pot. Repotting into a larger pot with fresh compost should see the plant need less frequent watering.
Peace lilies will happily grow in most indoor pot types, but some materials have better water retention than others.
Unglazed terracotta pots are naturally porous and will drain more quickly than plastic pots. Water will slowly seep through the natural clay as well as the drainage holes.
This is great for preventing waterlogging and root rot, but does mean you’ll need to water more often. As plastic pots hold onto water more readily, you need to make extra sure they drain well so as to avoid overwatering.
All potting soils have a slightly different composition, and some mixes will drain more freely than others.
Peace lilies like a moisture-retentive soil with plenty of organic matter but a loose, open and well-draining structure. If the soil mix is too dense, it will be prone to waterlogging which prevents oxygen from reaching the roots.
Avoid watering your peace lily whilst the soil is still damp. You can also incorporate some orchid or cactus soil, or add perlite or gravel to help lighten the potting mix.
In warmer climates, or very well-heated homes, foliage will transpire and lose water more quickly. If your plant is near a heat source, it’ll need watering more often than if you keep it in a cooler spot.
A peace lily in a very humid location will need watering less often. This applies whether your climate has high humidity or you simply keep your plant in a humid room.
Peace lilies love bathrooms, which replicate closely the warm, humid environments they originate from. A bathroom-dwelling plant needs less frequent watering than one in a bedroom, kitchen or living room.
Best practice for watering a peace lily
Now you’ve a good idea how much and how often to water your peace lily, let’s get into the specifics of how to water.
What to water with
Tap water is perfectly fine for watering peace lilies, but don’t pour it on fresh out of the tap. They’re adapted to warm tropical rains, so very cold water can shock their roots.
Plus they’re sensitive to chlorine, which can burn their leaf margins and tips. If you live in an area with chlorinated water it’s best to let the chlorine evaporate before using it on your peace lily.
Fill your usual watering can and leave the water to sit for a day so it loses its chlorine and reaches room temperature. Or, for truly pampered plants, give them bottled or filtered water instead.
How to water
You can water your plant on the soil’s surface, or stand it in water so it absorbs as much as it needs. Either way is fine, though bottom-up watering allows for a deeper soak and is preferable if your plant is very dry.
Dry plants can develop a hard, dry crust on the soil’s surface that inhibits how much water can seep down into the soil.
To bottom water, place the pot (minus its saucer or pot cover) into a sink or bucket with enough water to reach halfway up the pot. Leave it there until the top inch of soil feels moist.
If you’re top watering, keep pouring onto soil until water trickles from the drainage holes; try to avoid splashing water on the leaves as it can cause spotting.
Don’t leave any surplus water sitting in the saucer or pot cover; submerged roots are likely to succumb to root rot, which can be hard to recover from.
Can you overwater a peace lily?
It’s very easy to overwater a peace lily in your enthusiasm to water it often enough.
The early signs of overwatering look much like underwatering – a drooping plant, often with pale, yellowing leaves. This can see you reaching for the watering can when it’s the very last thing your poor plant needs!
If the plant is persistently overwatered, symptoms gradually become more severe. Foliage may start to develop water blisters as the roots absorb more water than the plant can use.
In time, overwatering can lead to fungal disease, spotting and browning of the leaves and ultimately root rot.
Protect your peace lily by making sure the pot and soil drain freely after watering – and always check the soil moisture before watering.
If you’ve arrived here because your peace lily is wilting and looking sorry for itself, rest assured – you can help it recover. Have a look at my guide to help you fix a drooping peace lily.