Peace Lily Leaves Turning Brown? Here’s Why


If you’ve been a long-time reader of Indoor plants for Beginners, then you may remember my post about peace lily flowers turning brown and what to do about it. That’s not your issue though. Instead, it’s the leaves of your peace lily that have browned. Why is this happening?

Why are my peace lily leaves turning brown? Peace lily leaves turn brown due to these 8 common issues:

  • Overdoing it on the fertilizer
  • Salt buildup
  • Using hard water
  • Using soft water
  • Improper humidity
  • Underwatering
  • Overwatering
  • Excess light

Whew! There sure are a lot of factors that can contribute to the browned leaves of your peace lily. If you followed my advice from any of my previous articles and were able to nurse your peace lily flowers back to health, then you don’t want to stand by and let your browning leaves suffer now. Keep reading to learn more about why your peace lily leaves have browned and what to do about it!

What Causes Peace Lily Leaves to Turn Brown?

Peace lilies can be a finicky houseplant. As the list above shows, doing too much of one thing or too little of another is enough to cause the tips to brown and before you know it, the entire leaf is browning.

Making the following mistakes is common, but realizing that they’re mistakes and then correcting them can save your peace lily and make you a better indoor gardener at the same time.

The 8 causes of peace lily leaf browning & how to correct each of them.

Too Much Fertilizer

How often do you fertilize your peace lily? If you’re new to raising houseplants, you might assume that each plant in your indoor garden needs fertilizing at the same intervals. That simply isn’t true.

Some species of indoor plants are frequent fertilizer feeders while others­–like the peace lily–can go far longer without fertilizer.

Plan for six-week intervals between fertilizing periods for the peace lily. Your first issuance of fertilizer should be in the late winter ahead of the growing season. In that regard at least, the peace lily is a lot like the other plants in your indoor garden.

Then, as the growing season gets underway in the spring, you want to fertilize your peace lily yet a second time. Some indoor gardeners will fertilize once more, but I’d say to use your discretion on that.

What kind of fertilizer should you give the peace lily?

Make sure it has the same amount of potassium, nitrogen, and phosphorus, with a 20-20-20 ratio.

Also, most importantly, please don’t feed the peace lily fertilizer at full strength! Mix the fertilizer with water to dilute it until it’s about half as strong as it should be.

Besides just color changes in the peace lily leaves, the flower may become green to suggest that you’re fertilizing too much. Take heed of these signs and scale back on the fertilizer.

If You’ve Enjoyed This, You’ll Love: How to Fix Using Too Much Miracle-Gro on Your Plants

Salt Buildup

Although plant fertilizers are designed to deliver nutrients to your indoor plant such as potassium, nitrogen, and phosphorus, those aren’t the only three ingredients in these commercially available products. Since fertilizers are soluble, meaning they dissolve in water, they must contain salt.

Your peace lily might not only receive salt from fertilizer though. Depending on the quality of your water, which I’ll talk more about later, the H2O you give your plant may be saltier than you think.

If too much salt accumulates in the water, your peace lily will indicate as much to you with a leaf changing color from green to brown.

Fortunately, this is one of the easier issues of peace lily care to fix. You should irrigate your houseplant with distilled water until you’re confident the salt is gone. Then, discontinue the above behavior. 

Using Hard Water

If you use any other type of water on your peace lily than distilled water, you’re unintentionally also feeding the peace lily minerals such as calcium.

The harder your water is, the more calcium your peace lily is receiving.

What is hard water anyway?

This is something I’ve written about here on indoor plant for beginners before but we’re due for a recap.

All water that comes right from the tap is somewhere between hard and soft.

The easiest & most cost effective way I know of to measure water hardness is by gauging the milligrams per liter (mg/L) of calcium carbonate in the water.

To determine which water you’re using to feed your plants or in this case, your peace lily, you can use an at-home testing kit such as the Pro Water Hardness Test Kit from Amazon.

Using a water hardness test kit makes finding out what hardness of water I was feeding my peace lilies extremely easy

If your water has 60 mg/L of calcium carbonate or less, then it’s soft water. If you get a reading between 61 and 129 mg/L, your water is moderately hard. If the test reads 121 mg/L through 180 mg/L, then the water is hard. A reading over 180 mg/L is considered very hard.

What exactly does it mean when your water is harder than softer?

Is it a bad thing? Hard water has more minerals than average, including magnesium and calcium. The minerals in hard water can clog up your plumbing. You might notice that eventually, your faucets and showers are constantly a lower pressure than they once were.

As you bathe in hard water, you’ll probably also have soap residue on your body and your hair, so your hair might look flat and your skin will be dry. Even your clothes are affected, becoming dull and taking on a rougher texture.

Take a look at the dishes that come out of your sink or dishwasher too. They might develop spots that look chalk-like and white. The same will happen to your faucets.

If your faucets are made of porcelain especially, the stains hard water can leave behind are very apparent (not to mention upsetting!).

The calcium and other minerals in hard water can accumulate in your plants too, affecting the peace lily in particular.

Now, granted, some calcium for plants is a good thing. Houseplants need calcium for cell wall strength and to combat the effects of organic acids and alkali salts. However, too much calcium can turn your peace lily’s leaves brown.

Using Soft Water

If you’ve determined that your water at home is hard, the natural reaction is to mitigate the effects of hard water with a water filter or softener. Both these measures are fine to a degree, but you want to make sure you don’t create another problem by trying to solve the first one.  

A water softener will remove minerals like calcium by introducing potassium or sodium to the water. As you can imagine, frequently relying on a water softener can add too much salt, which I discussed earlier as an issue for the peace lily.

Also, using a water softener could deprive your peace lily of the calcium it needs, leading to a deficiency. One of the symptoms of a calcium deficiency in houseplants is–you guessed it–brown leaves.

Improper Humidity

The peace lily is considered a tropical plant, and as such, it has stronger humidity needs than your average houseplant. You want to do your best to keep the temperature range around your peace lily between 65 and 80 degrees Fahrenheit and humidity around 50 percent.

I recently wrote a post about how to achieve humidity for your houseplants. No, you don’t need to spend all day misting the plant. Instead, you can try a humidifier, heat lamps, a heat mat, or even a portable radiator.

If you want to know whether your humidity is high enough for your peace lily, you can do a very easy, free test at home.

  • Take a glass and add a few ice cubes, no more than three.
  • Pour some water in and stir a bit.
  • Then, wait for about five minutes and see how your glass changes, if it changes at all.

If the glass doesn’t have any condensation or moisture on it after the allotted time, then it’s not humid enough in your home or office.

If you have so much condensation around the glass that even your coaster is getting soaked, it’s too humid.

Without enough humidity, the peace lily’s leaf tips will become brown. More alarmingly, your plant won’t grow! You may have to keep adjusting the humidity, as the peace lily absorbs moisture through its leaves, reducing humidity as it does so.

You can’t set it and forget it with the peace lily!

Underwatering

Besides fertilizing and humidity, another area of peace lily care to pay attention to is your watering habits. You know better now than to use plain, old tap water for your peace lily.

Even if you give the plant only the most perfectly-balanced water, if you overdo it or underdo it, you’ll still end up with brown leaves.

Granted, the peace lily does have somewhat strange habits regarding watering. You’re supposed to let the houseplant get a bit droopy and dried out before you water it again.

In other plants, drooping leaves would be a cry for help, but it’s just the peace lily’s way of letting you know that it’s time for you to water it again.

Then, when you water your plant, you should give the peace lily a lot of water at one time until the next watering period. You can see how mistakes can happen, especially if you’re new to indoor gardening.

In most indoor settings, you only have to water the peace lily about every 5 to 10 days , but please don’t forget it for too much longer than that.

The peace lily is resilient in that if its leaves begin seriously drooping, misting it with water can revive the plant to an extent. You do need to get into a better watering schedule going forward though.

While leaf drooping is normal and a sign that you should plan to water your peace lily the next day, drooping + brown leaves signifies that you’re a chronic under-waterer.

Overwatering

Yet another reason the peace lily’s leaves may turn brown is if you overwater the plant. Some indoor gardeners realize through trial and error that they haven’t watered their peace lily often enough, so they begin to overcompensate.

Remember, you want to water your peace lily about once every week. That goes for the summertime as well, but you might mist the plant more often to keep it perky and hydrated.

If you’re watering the peace lily every day or even several times a week regardless of season, you’re overdoing it.

The peace lily has develeoped fairly obvious ways of letting you know that you’ve over watered it.

A few of the more obvious signs you’ve overwatered your peace lilly include:

  • browning leaves, especially at the tips
  • severe leaf drooping
  • and rotted roots

If you’re not familiar, root rot is a plant disease that can kill many a species of houseplant. Some species are very sensitive to root rot and others a little less so, but the issue still needs immediate addressing.

The roots of your peace lily should be firm and white. If they become mushy and brown or black, the roots are dying or have already died. This is typically accompanied by quite a rancid odor.

Treating root rot is a crapshoot; you can try, but if the disease has killed most of the roots by the time you realize root rot has set in then your plant is probably a goner.

Too Much Direct Light

Given its status as a tropical plant, you might assume the peace lily would be one of the many houseplants that thrive in direct sunlight.

That’s surprisingly not the case with peace lilies!

This houseplant species does best in light partial shade and can even survive in dim lighting and dark conditions, though I wouldn’t recommend dim lighting and dark conditions for long periods of time.

In the winter when sunlight is sparse, the peace lily prefers fluorescent lights.

A couple hours of direct sun here and there is fine and can sometimes be just what your peace lily needs. Especially if the peace lily has been drooping and you were reviving it with a thorough morning watering.

But beware of the full-on brunt of the sunlight, especially at its strongest points of the day (noon-2pm).

Anything more than an hour or two can quickly brown, and even burn, the leaves as well as the “spadix” , known as the flower your peace lily.

If that happens, move your plant immediately to more shaded conditions.

What Should You Do with the Brown Leaves of Your Peace Lily?

Whoops! You made one or more of the above mistakes and your peace lily’s leaves are most assuredly brown. What do you do?

First of all, don’t feel too bad or give up on them. While peace lilies aren’t necessarily a hard indoor plant to take care of, they do take a little experience to get the hang of their specific needy characteristics.

I recommend going through the list in the last section and pinpointing which mistake might have caused the brown leaves. Otherwise, once you fix the brown leaves now, you’ll repeat the same mistakes and end up in this same position again in a few days or weeks.

Next, take some clean gardening shears and remove the brown parts from the peace lily’s leaves. Don’t touch the green areas of the leaves. Make sure you’re taking better care of the peace lily from now on.

Final Thoughts

Your peace lily’s leaves can turn brown for a whole laundry list of reasons, including overwatering or underwatering, using water that’s overly hard or soft, adding too many minerals, and failing to provide adequate humidity and lighting conditions.

Although peace lily care isn’t always easy, once its white faux flower blooms, you’ll be so proud of all the hard work you’ve put in!

Fred Zimmer

I'm a lover of plants, animals, photography, & people, not necessarily in that order. Currently, I'm focused on photographing indoor plants & chachkies. I write & rewrite articles about creating an environment where indoor plants can thrive. I'm good at listening to music but bad at shopping to muzak.

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