Peace Lily Root Rot: 5 Key Signs + Treatment & Prevention
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Peace lily root rot can be a fatal condition, and you need to act quickly before it’s too late. I’ve lost a few plants to root rot myself, so I know how quickly it can seem to spring out of nowhere. Fortunately, my experience with peace lilies shows that they’re pretty tough plants, and if you catch the problem early and treat it correctly, you stand a good chance of saving the entire plant or part of it.
Root rot is caused by bacteria or fungus attacking the peace lily’s roots. Above-ground signs include drooping leaves, soft or mushy stems, a musty odor from the soil, yellow or brown leaves and stem discoloration. Root rot treatment includes removing the plant from the pot, clearing away infected soil, applying a mild hydrogen peroxide solution to kill pathogens and repotting the peace lily in fresh soil.
If you discover your peace lily is showing signs of root disease, don’t lose heart. In this article, I’ll show you how to recognize the signs of peace lily root rot, as well as how to treat it and prevent it from occurring again.
Let’s get started!
Peace Lily Root Rot- What Is It?
A study by The PharmaJournal shows that root rot is caused by pathogens entering the plant’s system and progressively destroying cell walls. A couple of the main culprits of root rot are Phytophthora parasitic and Cylindrocladium spathiphyllum. These microbes attack the root tissue, killing it and leaving it to decay in the soil.
The root system is the lifeline of the plant. If it can’t do its job of absorbing water, nutrients and oxygen, the plant will quickly suffer from dehydration and malnutrition. That’s when the leaves start to take on a yellow or brown color and the stems begin to rot from the bottom up. If left untreated, the plant will die.
5 Signs of Root Rot in a Peace Lily
Unfortunately, root rot begins where you can’t see it- under the soil surface. So you may not be aware that there’s a problem until there are visible signs of trouble above ground.
If you see any of these 5 signs, it’s time to investigate further:
- Drooping leaves
- Mushy stems
- A musty odor from the soil
- Yellowing or brown leaves
- Stems turning brown or black
1. Drooping Leaves
Peace lilies are notorious for being a bit dramatic, and they’ll start drooping their leaves in response to almost any stress factor. It could be that your plant needs water- or it may be that root rot is setting in.
So the first thing to do when you see your plant’s leaves wilting is to check the soil.
Root rot is mostly associated with damp conditions. If the soil is wet and you haven’t watered in the last few hours, it could mean the issue is root rot. But if the soil feels dry, water the plant. If the leaves soon respond by becoming firmer and lifting, you may have resolved the issue.
2. Mushy Stems
With root rot, the fungal invasion progresses internally. It destroys the plant’s cell walls from roots to stem (and eventually, the leaves). Progressive decay causes your plant’s stems to become soft or squishy where they should normally be firm and smooth.
3. Musty Smell
Like any organic matter, dead root tissue can develop an odor as it decomposes. A stale, unpleasant smell is a warning that the plant is rotting from the bottom up.
4. Discolored Leaves
Typically, the oldest leaves at the plant’s base are the first to take on a sickly color when the plant is stressed from overwatering or worse, rotting roots. This is your peace lily’s way of cutting loose the most expendable leaves to preserve the newer growth.
5. Discolored, Soft Root Sections
The only surefire way to confirm that your peace lily has root rot (and not some other problem) is to look at the roots themselves.
Let’s look at healthy peace lily roots vs unhealthy ones.
Healthy root systems are firm and white-to-tan in color:
On the other hand, sick root systems look bad- they may be soft and spongy or have a brown color. In extreme cases, they can be black and rotten. This photo shows what a rotted root tip looks like:
The difference is quite obvious, so don’t worry- you should be able to tell pretty easily if root rot is the cause of your plant’s problems.
How to Repot a Peace Lily With Root Rot
Once you’ve identified unhealthy peace lily roots, you need to address the issue asap.
Here are the steps to successfully treat a sick peace lily:
1. Gather Supplies
This is what you’ll need:
- A work surface covered by an old sheet, newspaper or brown paper.
- A new, appropriately sized pot, a little larger than the circumference of the roots and with adequate drainage holes.
- Well-draining soil. A houseplant potting mix should work well, or you can do a 2:2:1 mix of soil, sand and perlite.
- Gardening scissors or gardening shears cleaned well with alcohol
- 3% hydrogen peroxide
2. Take the Peace Lily Out of the Pot
If you haven’t done so already, take your peace lily out of the pot.
Tip the pot downward and work the plant free, being careful not to pull on the already-weakened stems. If your plant is in a plastic pot, try squeezing the sides to get the soil to release, or run a knife along the pot’s inner side. You could also use a chopstick or a pencil to poke upward through the pot’s drainage holes.
It may take some time, but go slowly and use a gentle touch. If nothing else works, consider breaking your pot to get the plant out.
NOTE: If the pot is terra cotta, unglazed ceramic or cement, throw it away– the pathogens can get into the porous material, and there’s no reliable way to sterilize the pot. You don’t want to spread the infection to another plant!
If your pot is plastic, fully-sealed ceramic or another non-porous material, soak it in a 1:10 bleach/water solution for a few hours, then rinse and allow to air-dry.
3. Remove Old Soil
Brush away all the old soil you can, letting it fall onto your work surface. Don’t try to save any of this soil- it’s contaminated and you won’t be able to clean it. Instead, throw it all away.
After you’ve brushed off as much soil as possible, rinse the roots under running water to remove any remaining traces. This lets you get a good look at the roots themselves and washes away pathogens.
4. Inspect the Roots
Carefully look over the entire root system. Here’s what you’re looking for:
- Sections that are brown or black
- Squishy or soft sections
- A slimy coating on root tips
- Any areas that have a musty odor
- Root tips that break off on their own or with a light touch
Here’s what the brown discoloration can look like, marked with arrows:
And here’s a better look with more of the soil brushed away:
Using your sanitized scissors or shears, cut off any damaged parts. Cut all the back to where you see healthy white or tan roots.
5. Wash Roots with Hydrogen Peroxide
As long as you dilute it properly, hydrogen peroxide is effective at killing pathogens without harming your plant.
Dilute the 3% hydrogen peroxide using 1 part hydrogen peroxide to 2 parts water, then apply the mixture to the roots. You’ve got a couple of options:
- Use a clean spray bottle saturate the roots
- Hold your plant over a sink/tub and pour the solution over the roots
- Submerge the roots into a large container of hydrogen peroxide solution
After treatment, allow the root ball to sit out in the room air for an hour or two.
6. Repot in Fresh Soil
Take your new pot and fill it about a third full. Put your peace lily in the pot and fill around the sides with more soil. Gently press down to dislodge large air pockets, but don’t push so hard that you compact the soil.
7. Provide Proper Care During Recovery
Once your peace lily is safely repotted, you will obviously want it to recover as soon as possible. But be patient- depending on how severe the damage was, it could take up to 3 weeks for your plant to start perking up.
Here’s what you can do in the meantime:
- Hold off on watering for a couple of days to give the cut root sections a chance to callous over before getting exposed to moisture.
- Do not apply fertilizer until the plant is fully recovered (at least 4 weeks).
- Place the plant where it receives filtered bright light; keep out of direct sun.
- Keep it away from cold and drafts.
If your peace lily hasn’t made much progress after a couple of weeks, it may be too far gone to save. However, you can try unpotting your plant again and seeing if you can find any healthy root sections. If there are any intact roots, you can separate them from the plant and try to propagate a new peace lily.
Preventing Peace Lily Root Rot
Root rot prevention is by far the best strategy.
Giving your peace lily too much water is the top cause of root rot, for a few reasons:
- Wet soil is a hospitable environment for bacteria/fungi to multiply
- Soggy plant roots cannot access oxygen that’s normally in the soil’s air pockets, weakening the plant and leaving it prone to infection
- Overwatering can wash away nutrients like potassium, nitrogen and other micronutrients
So keeping your peace lily’s moisture at a healthy level is critical. We’ve dedicated a post to covering the topic of recognizing and treating overwatering in peace lilies in much more detail. But here’s a quick rundown of how overwatering can occur:
- Watering too frequently
- A pot that’s too large
- Heavy or compacted soil
- Watering at the wrong time of day
- Obstructed pot drainage holes
- Sitting in a puddle of water
- Giving too much water during the dormant phase
However, under-watering can also cause root rot- it’s happened to me before. When the roots get too dried out, they start to die off. Then when you notice the under-watering problem and go to rehydrate your plant, the moisture makes the dead sections start to decay and spread infection to the rest of the root ball.
So the very best strategy for keeping root rot away from your peace lily is to maintain a consistent watering schedule that’s appropriate for your plant’s needs.
Frequently Asked Questions about Peace Lily Root Rot
Root rot is a problem to take seriously, but I hope this article has given you confidence that you can help your peace lily recover.
Unfortunately, you can’t see the first signs of root rot since they occur below the soil. But health problems will show in other parts of the plant, and by paying close attention and monitoring your plant care routine, you can usually save a sick peace lily. So don’t be afraid to get in there and help your plant out!
I’d love to hear from you! Do you have any other questions about identifying or dealing with root rot or peace lily diseases? If you’re wondering, someone else probably is too- so please feel free to ask or share your experiences in the comments!