If you notice the leaves on your Peace Lily starting to change color, it’s usually a sign that your plant is unhappy. Typically, you’ll see them turn yellow first before they eventually go brown. However, there are a few situations where those lush green leaves can turn brown almost overnight.
The Culprits
It’s pretty rare for houseplants to go from healthy to brown in the blink of an eye; usually, they give you a “yellow warning” first. But sometimes, you’ll encounter sudden leaf wilt. This is when the leaves skip the yellow phase entirely and go straight to brown. Since the plant is losing its foliage so quickly, it’s definitely a cause for concern.
It’s pretty obvious that this isn’t normal behavior for a Peace Lily. Even when a leaf dies off naturally to make room for new growth, it turns yellow before browning. If your plant is dropping leaves suddenly, it’s in a bit of a life-or-death crisis.
The two main reasons for sudden browning are:
- Sunburn
- Fungal infection
Sunburn
While Peace Lilies love a bright spot, they absolutely cannot handle direct sunlight. If they’re left in the path of harsh rays, they’ll get a nasty sunburn. Within just a few hours, large sections of the leaves—or even the whole leaf—will turn brown, dark brown, or even crispy black.
What to do:
- Move your Peace Lily out of the sun immediately.
- Place it in a shady spot to recover.
- Wait a day or two, then prune away the burnt leaves (unfortunately, once they’re scorched, there’s no saving them).
Fungal Infection
If you’re sure your plant hasn’t been sitting in the sun, those sudden brown patches are likely caused by a fungus called Phytophthora. This fungus lives in the soil and attacks the roots, cutting off the plant’s ability to take in water and nutrients (this is known as Phytophthora root rot).
The result is sudden wilting of the leaves and rot starting from the base of the plant. You’ll notice black spots at the bottom of the leaf stems, and the roots will turn dark brown and mushy. Because Peace Lilies are soft-stemmed plants, it doesn’t take long for the infection to spread through the entire thing.
What to do:
Unfortunately, there is no cure for Phytophthora root rot. To prevent the fungus from spreading to your other plants, you’ll need to dispose of the plant, the soil, and the pot in the trash—sealing them in a plastic bag is the safest bet.
To prevent this in the future, make sure your plant has great drainage. Avoid letting it sit in standing water (soggy soil is a fungus’s best friend!) and be careful not to over-fertilize.
