Oh, the problems of the Peace Lily. Yellow leaves turning black, brown spots appearing, and leaves wilting and drooping because you can’t get them to drink enough water.
Or, at least that’s what you think the problem is. There’s actually a few things that contribute to the leaves of peace lilies turning yellow and paling in color before that.
Spot the paling leaves early enough, and you can rectify the problems before the leaves turn yellow. If you don’t, they will need to be trimmed because once yellow, they will never regain their dark green foliage.
Gardeners make it appear so easy to grow the gorgeous peace lily as a houseplant. You try and what happens? All sorts of problems start appearing. You fix one issue, another appears.
The Simplified Approach to Caring for a Peace Lily Indoors
To state the obvious, a peace lily with yellow leaves is a problem. The natural leaf color should be a dark green shade. The instant the dark green color fades is when to start looking at what’s going wrong with the growing conditions.
Possible causes of yellowing leaves on a peace lily grown indoors include:
1 – Sunburn
Peace lilies don’t need much direct sunlight to grow. They do plenty well in shadier spots. Too much direct sunlight burns the leaves and that’s why they turn yellow.
Peace lily + yellow leaves = sunburn.
If the plant is left in the same stressful growing climate, the problem gets worse causing the yellow leaves to wilt/droop until they’ll eventually just drop off the plant – dead.
2 – Soil Problems
For a peace lily grown as a houseplant, the soil needs to be kept moist, yet at the same time, using a well-draining soil.
Win the watering battle by feeding your peace lily when it tells you it needs a drink. Generally, you only need to water it once a week and when that time comes, the leaves will sag slightly. Not terribly wilted, but a slight sag on them and that’s when they need a drink. Just as they’re beginning to droop (see some other causes of drooping).
Pay attention to how often it wilts because when it happens every three to four days, chances are, it needs a bigger pot. But, check the drainage holes of the plant pot first because it is possible those can get clogged causing the plant to be sitting in standing water.
The soil to use should be well draining and when you do water it, pour the water into the soil until you see it pour out of the drainage holes so you know it’s had a good soaking. That’s enough to keep the soil moist for up to a week.
3 – Water Issues
If it’s not your watering frequency that’s the problem, it can be the type of water you use. Tap water, as you may know, has many additives in it and a lot of those are not good for plants (or human consumption).
You should always use filtered water for peace lilies because anything they don’t like, they let you know by throwing a hissy fit turning all shades of the wrong colors.
The main concern with tap water is calcium. Too much will cause leaf discoloration including yellowing, brown spots and in the worst case – blackening of the leaves.
If your peace lily’s leaves have brown spots, check the base of the plant pot drainage holes for white speckles. These are mineral deposits from harsh water chemicals.
If those are present, use bottled water to flush the soil getting rid of the mineral build up. Trim the ruined leaves off and go back to watering as usual, only this time with filtered water.
4 – Sometimes, the Yellowing Is Just Natural
Don’t mistake the bottom leaves on a peace lily turning yellow as a sign of inadequate watering. The bottom leaves will naturally turn yellow.
They’re the first ones the plant kills off, which is why the top leaves are the lush dark green with what should be plenty of blooms.
Pruning Yellow Leaves on a Peace Lily
Once the leaves on a peace lily turn yellow, no matter what you do, they’ll never turn green again. What they will do is develop brown spots first, then eventually the leaves start turning black, at which point they’re dead and fall off.
Do yourself and the rest of your plant’s leaves a favor and snip off every yellow leaf on the plant to give it a fighting chance of developing fresh green foliage.
You’ll notice the darker leaves toward the base of the plant tend to turn yellow, then brown and die. This is natural and the leaves closer to the base of the plant do need more regular pruning.
What we see as a single flower on a peace lily is actually a cluster of tiny flowers attached to one big white leaf. Each stalk on a peace lily can only flower once. Once it’s spent, it starts to turn green and wilt, at which point they’re spent flowers.
The stalk has done its job and the entire stalk is then useless because it only flowers once. Once the flower starts to turn from white to green and wilt, prune it from the base of the plant.
If you only trim the tip of the stalk, the leaves at the base of the plant will naturally turn yellow and die. This is just the plant’s way of killing off spent stalks.
If the only yellow leaves or brown leaves are at the base of the plant and the flower at the top of the stalk is spent, there’s nothing wrong. Just prune off the discolored leaves to let a new stalk grow in.
Fertilizing Peace Lilies
Peace lily’s prefer half strength fertilizer that’s either 10-10-10 or 20-20-20 formulas. They only need fertilizer added every 6-8 weeks.
However, if you’re growing these indoors, there’s a much easier alternative that some have described as “steroids for houseplants.”
That’s using Miracle Grow’s indoor plant food spike sticks (amazon). They last for up to two months and all you need to do is poke a stick into the plant soil and leave it there.
These things work wonders for getting tremendous blooms from peace lilies and since it’s stick and forget, it’s a pretty fool proof way to add all the micronutrients a peace lily needs to thrive, without having to mix half strength fertilizer solutions.
You can always get creative and make your own fertilizer as well.
The Humidity Requirements for a Peace Lily
To increase the humidity, you can use a pebble tray instead of just parking your peace lily on a saucer so as the water evaporates, the humidity rises to moisten the leaves. With a humidity tray under the plant, you won’t need to mist the leaves as often.
While peace lilies don’t need watering too frequently, without a humidifier or a humidity tray, you’ll likely need to mist the plants leaves two to three times daily when humidity is low.
Ideally, humidity should be above 50% relative humidity. When it’s not, the plant won’t bloom as you’d expect it to.