How Much and How Often Should You Water Peace Lilies?

Think back to the first few houseplants you ever bought (or perhaps, were gifted). A Peace Lily is likely to be in that group. Known as fuss-free and favored for their gorgeous white blooms, they are one of the most beginner-friendly houseplants.

While their care is relatively simple, it is the most basic tasks that most get wrong – especially watering. These plants love moisture but also can’t be left to sit in soggy soil, so a fine balance is required to keep them happy year-round.

Luckily, we’ve rounded up absolutely everything you need to know about watering Peace Lilies. From times to factors that may influence your watering schedule, you’ll have watering handled in no time.

The Long Answer

Peace Lily is the common name for a vast genus of plants known as Spathiphyllum. Part of the popular Arum family, along with other common houseplants like Alocasias and Philodendrons, they are categorized by their spadix blooms. The spiked structure holding the flowers is surrounded by a modified leaf – usually white – that many mistake for the flower itself.

The most common Spathiphyllum you’ll find in stores is Spathiphyllum wallisii, usually what people picture when they hear the word Peace Lily. But there are just under 50 other species to choose from, each with similar growing requirements.

While they can grow outdoors in shady areas in tropical climates, they are most often grown as houseplants. They make wonderful gifts for houseplant beginners and are relatively easy to care for once their needs are understood.

They also come with a wide range of other benefits. As part of the famous NASA Clean Air study, Peace Lilies demonstrated a great ability to remove Volatile Organic Compounds (VOCs) from the air in our homes. In reality, this benefit is only realized with masses of plants. Luckily, they are also easy to divide, allowing you to fill your home with ease.

One of the key components of their care that many get wrong is watering. But, with an understanding of their native habitats, the process will become a whole lot easier.

Native Habitats

Members of the genus are naturally distributed around Central and South America. They grow on the floors of tropical rainforests, appreciating the moisture, humidity and heat in these areas. The shade provided by the trees above is what makes them suitable for low-light areas of our homes, although they may not flower as prolifically in these conditions.

By nature, rainforests are packed with moisture, with humidity of 90% and higher during the rainy season. The soil on the forest floor is rich and consistently moist, but not waterlogged. Short bursts of rain saturate the soil and quickly drain away, leaving the roots moist but with plenty of oxygen to keep the plants alive.

Keeping these conditions in mind, it’s easy to see why Peace Lilies need frequent watering. However, drainage is also a vital component, as these plants are never left in standing water for long periods in their native habitats.

How Often Do Peace Lilies Need Water?

Many indoor gardeners, especially new ones with few houseplants in their collection, like to water on a set schedule. For Peace Lilies, this would mean watering around once per week, increasing the frequency in summer when temperatures are higher.

However, this practice leads to several issues. As much as we would like them to, they do not operate on a strict schedule. Just like humans, they are impacted by changes in their environments that can influence how much water remains in the soil.

Although using a schedule can be incredibly helpful if you forget to water your plants, it ignores the actual moisture levels in the soil. Several factors (discussed later) will impact how quickly the soil dries out and can change from day to day. A schedule will eventually lead to underwatering or worse, overwatering, creating several problems with growth.

Instead, keep a close eye on the soil every few days. As soon as you notice the top layer of soil dry out, it’s time to water again. Don’t wait too long or you risk wilting and yellowing. Similarly, don’t water when the top layer of soil is still moist, as this can lead to root rot.

This of course only applies if you have the right levels of drainage in the soil and the pot itself. Excess water should be able to flow freely between soil particles and out of the drainage holes at the bottom of the container. This maintains essential airflow around the roots, providing oxygen and preventing disease.

Without this drainage, even watering at the perfect time won’t be able to save your plants from damage. Use an airy houseplant potting mix when repotting containing a few handfuls of perlite and coconut coir and choose a container with drainage holes at the bottom (or you can drill your own).

How Much Water Do They Need?

When it comes time to start watering, you may be wondering how much water you should add. But the process is not an exact science, with no specific amount required. Measuring jugs will ignore the size of your plant, the speed of growth and the current moisture levels in the soil. In other words, ‘how much water’ is the wrong question.

Instead, you should continue to add water until the soil is completely saturated. As it can be hard to tell what’s going on at the bottom of the pot, water running from the drainage holes is usually your sign that all parts of the soil are watered.

Technique is also important when watering. You should always water evenly throughout the whole pot, rather than concentrating the stream in one area. In this case, water may leave the drainage holes on one side only, meaning the roots on the other side of the container are likely still dry.

If your soil is compacted or excessively dry, water coming from the drainage holes is no longer a good indicator of saturation. That’s because compacted soil becomes hydrophobic, resisting moisture. Water will run down the sides of the pot and out the bottom without penetrating the top layer at all.

When soil is compacted, bottom watering is a much better technique than watering from the top. Leave the pot in a container or sink filled with water, allowing the soil to draw moisture from the drainage holes at the bottom. The dry soil will slowly soak up moisture until it has covered all areas of the pot. After around 30 minutes, remove the pot, drain any excess and replace the plant.

Factors That Impact Watering Schedules

Watering times are never completely set, changing as the environment around your plant changes. Take a look at these factors that can impact the levels of moisture in the soil. Keep an eye on any changes and how they can change watering times day by day.

Light Levels

Peace Lilies are one of the most commonly recommended plants for low-light areas. They can adapt to most lighting levels except for direct sun, growing most successfully in bright indirect light indoors.

The amount of sunlight your plant gets is one of the largest determinants of watering frequency. When left in low light, the moisture in the soil will evaporate far slower than it would with more sun. The plant will also grow slower, using up far less water for photosynthesis. That means you’ll need to water much less often to maintain consistent moisture levels in the soil without overwatering.

In higher-light areas, moisture will evaporate much quicker. With a full day of bright indirect light, or even an hour or two of direct morning sun, your Peace Lily may need watering more than once per week. It all depends on the intensity of the light source and how it impacts moisture levels in the soil.

Once you’ve placed your plant in its ideal spot, take a couple of weeks to identify how the light levels impact soil moisture content. This should give you a better idea of approximately when you need to consider watering week by week.

Even when you have a general estimate, it’s vital to test the soil before you water. If the top layer still feels moist to the touch, wait a couple of days before watering again.

Temperature

Temperature and season also influence watering frequency, generally over a longer term. Peace Lilies need warm temperatures of around 75F throughout the year to grow successfully. But, as we all know, temperatures indoors aren’t always that conveniently consistent.

Periods of higher temperatures, usually in summer, will cause the soil to dry out far quicker. If you want to avoid the problems associated with overwatering, you will need to water more often, potentially twice a week or more depending on the performance of the plant.

Sudden drops in temperature will slow evaporation. If temperatures drop below 60F, the plant will also slow growth dramatically, absorbing far less water than normal.

These changes typically occur with the seasons. In fall and winter when temperatures are lower, your plant may only need water once every two weeks or so. This will increase as temperatures do in spring and summer when growth is spurred. Keep an eye on your thermometer and how it can impact the soil.

Growth Rate

Water is one of the essential components in the process of photosynthesis. Peace Lilies that are growing quickly will use up more moisture than slow growers, needing watering more often.

Several things can influence the growth of your plant, from light to fertilizing and more. You’ll need to use your judgment and frequent soil checks to determine how quickly moisture is sapped from the soil.

Signs of Overwatering

Unfortunately, Peace Lilies are frequent victims of overwatering, especially for new plant owners. Many assume their love of moisture means the soil needs to be consistently wet. These conditions ultimately suffocate the roots and lead to a problem known as root rot.

Signs of root rot include yellowing leaves, wilting and soft mushy stems. Below the soil line, the roots will also become soft, rotting and preventing moisture and nutrient absorption. As no moisture is absorbed by the plant, the soil will likely stay moist or soggy for longer periods, exacerbating the problem.

At the first sign of overwatering, leave the soil to dry out more before watering again. If the plant is still wilting, repot immediately into fresh, well-draining soil. Trim the rotten roots to stop the fungus from spreading. Also, make sure the new container has enough drainage holes to stop the problem from occurring again in the future.

Signs of Underwatering

Signs of underwatering are much clearer. You will first notice the leaves beginning to wilt and fall over. This is due to the lack of water inside the cells that maintain structure in the plant.

If the problem persists, the edges of the leaves will begin to turn brown. Any existing flowers will also likely turn brown and dry up. Lack of humidity can also lead to brown tips, so make sure that is not the issue first before you look at your watering schedule.

Compacted, dry soil is another bad sign of underwatering. In these cases, water the plant from the bottom to completely saturate the soil. If the damage has not killed off any of the roots, the leaves should start to grow upright again within a couple of hours.