Plant care guide
Peace Lily Root Rot: Signs, Causes and How to Save It
Updated
Why does my Peace lily have root rot?
Root rot is likely when a peace lily wilts or yellows while its mix is still wet, and the roots are brown to black, soft, and shed their outer layer when pulled. It usually follows overwatering, a saucer of standing water, or a pot that is too big.
What to do first
Stop watering and unpot the plant. Cut away soft, dark roots, keep firm ones, and repot into fresh soilless mix in a clean pot only slightly larger than the remaining roots. Discard plants with almost no healthy roots.
Root rot is the problem most worth catching early on a peace lily. Clemson Extension’s peace lily factsheet says root and stem diseases are the most common peace lily problem. They are usually linked to overwatering.
Leaves alone cannot confirm it. You need to look at the mix and the roots.
Signs above the mix
University of Maryland Extension’s root rot page lists yellowing, browning and dieback of leaves, poor growth, and wilting. The key clue is wilting even when the mix is moist.
Penn State Extension’s root rot fact sheet adds slower growth, older leaves yellowing and falling, and dying leaf margins.
Clemson’s houseplant disorders guide notes that stems may be girdled at or near the soil line by a ring of brown or black tissue.
These leaf signs overlap with drought, fertilizer burn and a crowded pot. Penn State lists too little water, over-fertilization, chilling and a pot-bound plant among the causes of the same symptoms. That is why the roots decide it.
Confirm it at the roots
Slide the plant out of its pot and look:
| Root condition | What it means |
|---|---|
| White roots and root tips, crisp rather than limp | Healthy (Penn State) |
| Brown to black, soft or mushy roots | Rot (Maryland) |
| Outer layer slides off, leaving a thin thread | Rot (Maryland, Penn State) |
| Most roots stay behind in the pot when lifted | Advanced rot (Maryland) |
| Healthy roots in dry, light mix | Thirst; water thoroughly |
If the roots are healthy and the mix is dry, water instead. Our drooping peace lily guide sorts dry-mix wilting from wet-mix wilting.
What causes it
- Too much water. Clemson’s disorders guide explains that overwatering cuts the oxygen available to roots and favours root disease.
- A saucer of water. Clemson’s peace lily factsheet warns that letting the plant sit in excess water leads to root rot.
- A pot that is too big. Clemson says an oversized pot keeps the mix too wet.
- Dense mix. Maryland’s repotting guide warns that “potting soil” is often too dense for good aeration.
- Cold. NC State’s Spathiphyllum profile says extended periods below 4 °C (40 °F) can damage roots.
How to treat a peace lily with root rot
- Stop watering and empty any saucer or cover pot.
- Unpot and remove old mix so you can see every root.
- Cut out rotted roots with clean, sharp scissors. Keep firm, pale roots. Penn State notes that dead roots do not recover; new ones must grow.
- Use a clean pot. Maryland advises clean or new pots and sterile potting media, never garden soil.
- Size the pot to the roots that remain. Clemson warns that too large a pot keeps the mix too wet. After trimming, the original pot or a smaller one may fit better than a bigger one.
- Repot at the same depth in fresh soilless mix with an open drainage hole. Do not add a gravel layer.
- Water once, then wait. Maryland’s repotting guide says to wait until the top of the mix dries before watering again.
Keep the plant in bright, indirect light and away from vents. NC State gives 20–29 °C (68–85 °F) by day. Do not fertilize until new leaves appear; NC State notes that salt build-up can burn roots.
When to divide or discard
Maryland advises throwing away severely infected plants and separating infected plants from healthy ones. Clemson says that if most roots are dark, soft and dead, it is better to discard the plant.
A large clump may have one healthy section. NC State lists division as the main way to propagate peace lilies. Pot up any crown that still has firm roots, and discard the rest.
Prevent it next time
Water when the top of the mix has dried slightly, as Clemson advises. Never leave the pot standing in water. Repot only when roots fill the pot; see our peace lily repotting tips in the care guide.
Related guides: peace lily yellow leaves, moldy soil, fungus gnats and our houseplant root rot guide. The peace lily hub lists the rest.
References
- University of Maryland Extension: Root Rots of Indoor Plants
- Clemson Cooperative Extension, HGIC 1512: Peace Lily
- Clemson Cooperative Extension, HGIC 2251: Houseplant Diseases & Disorders
- Penn State Extension: Fungal Root Rots and Chemical Fungicide Use
- NC State Extension Gardener Plant Toolbox: Spathiphyllum
- University of Maryland Extension: Potting and Repotting Indoor Plants
How this guide was put together: University of Maryland Extension, Clemson Cooperative Extension, Penn State Extension and NC State Extension guidance.