PlantWhy

Root rot: symptoms, causes and how to save your plant

Root rot kills more houseplants than pests do, and it hides below the soil until the leaves give it away. Caught early, most plants can be saved. This guide explains why roots rot, how to tell healthy roots from rotten ones, and exactly what to do next.

Root rot: symptoms, causes and how to save your plant
Photo: Mokkie, CC BY-SA 3.0 · Wikimedia Commons
Main cause
Soggy soil with no air for the roots
Key sign
Soft, brown, smelly roots
Rescue window
Best within days of the first signs
Recovery time
4–8 weeks for new roots (estimated)

Why roots rot

Roots breathe. When the soil stays wet for long periods, the air spaces fill with water, roots suffocate and start to die. Dying tissue is then invaded by water mould and fungi such as Pythium, Phytophthora, Rhizoctonia and Fusarium, which spread the rot to healthy roots.

  • Overwatering: Watering on a schedule instead of checking the soil.
  • No drainage: A pot without holes, or a saucer and cover pot that hold standing water.
  • Cold: Wet soil below about 60 °F dries slowly and roots barely work, so winter is the riskiest season.
  • Heavy, old mix: Compacted or broken-down potting mix holds water like a sponge.
  • Oversized pot: A lot of soil the roots cannot reach stays damp for weeks.
Plants with thick rhizomes, like the ZZ plant, rot quickly in soil that stays wet.
Plants with thick rhizomes, like the ZZ plant, rot quickly in soil that stays wet. Photo: WeFt, CC BY-SA 3.0 · Wikimedia Commons

Symptoms: what root rot looks like

Above the soil, root rot often looks like thirst: the plant wilts even though the soil is wet. Watch for yellowing lower leaves, drooping that watering does not fix, brown leaf spots, stalled growth, a soft stem base and a sour or rotten smell from the pot. The only sure check is to look at the roots.

Healthy roots

  • White, cream or light tan (some species are naturally orange or brown).
  • Firm and springy when squeezed.
  • Smell of fresh, earthy soil.
  • Outer skin stays attached when pulled gently.
  • Fine root hairs at the tips.

Rotten roots

  • Dark brown to black, often slimy.
  • Soft and mushy; they break when touched.
  • Sour, swampy or rotten smell.
  • Outer layer slides off, leaving a thin thread.
  • Few or no living tips.
A fiddle-leaf fig dropping lower leaves can be a sign of trouble at the roots.
A fiddle-leaf fig dropping lower leaves can be a sign of trouble at the roots. Photo: Forest & Kim Starr, CC BY 3.0 · Wikimedia Commons

Step-by-step rescue

Work on newspaper or outdoors and have a clean pot and fresh mix ready before you start.

  1. Take the plant out: Tip the pot, support the base of the stem and slide the root ball out. If it sticks, run a knife around the inside of the pot.
  2. Wash the roots: Shake off loose soil, then rinse the roots under lukewarm running water so you can see every root clearly.
  3. Cut the rot: With clean, sharp scissors, cut every soft or dark root back to firm, pale tissue, plus about 1/4 in into healthy root.
  4. Disinfect the tools: Wipe the blades with rubbing alcohol (70%) between cuts and when you finish so you do not spread the disease.
  5. Let it breathe: Leave the roots on a paper towel in shade for 1–2 hours (succulents up to a day) so the cuts dry slightly.
  6. Use fresh mix: Never reuse the old soil. Choose a fresh, airy mix suited to the plant; add perlite or bark for extra drainage.
  7. Use a clean pot: Pick a pot with drainage holes, the same size or smaller than before, because the root system is now smaller. Scrub a reused pot with soap and hot water.
  8. Wait to water: Water lightly only after a few days, and from then on only when the top 1–2 in of soil is dry.

Aftercare and how much to remove

If you had to remove more than half of the roots, trim some leaves too, so the plant has less to support. Keep it in bright, indirect light at room temperature, away from direct sun, heaters and cold drafts. Do not fertilise until new growth appears, usually 4–8 weeks later (estimated). A fungicide labelled for root rot can help in some cases; follow the label exactly.

⚠️ If the whole root system is brown and mushy and the stem base is soft, repotting will not save the plant. Go straight to cuttings.

Too far gone? Save it with cuttings

Even when the roots are lost, healthy stems or leaves can start a new plant. Cut 4–6 in pieces from firm, green parts well above any rot, using a disinfected blade. Check that the cut surface is clean and pale with no brown streaks; if it is discoloured, cut higher.

  • Pothos, philodendron, monstera: Root stem cuttings with a node in water or moist perlite.
  • Snake plant: Root 3–4 in leaf sections in barely moist mix.
  • Succulents: Let leaves or stem tips dry for a few days, then lay them on dry mix.

Throw away the old soil and the rotten parts; do not compost them.

Succulents and orchids

Succulents and cacti rot fast because they store water. Signs are translucent, mushy leaves and a stem that turns black from the base up. Cut back to clean tissue, let the cuts callus for 2–3 days, pot into a gritty cactus mix and wait about a week before watering.

Orchids such as Phalaenopsis grow in bark, not soil. Healthy roots are silvery-green when dry and green when wet; rotten roots are brown, hollow and papery or mushy. Remove them, repot in fresh bark in a pot with plenty of holes, and water only when the roots turn silver again.

Echeveria and other succulents store water in their leaves and need fast-draining mix.
Echeveria and other succulents store water in their leaves and need fast-draining mix. Photo: EriaWei, CC BY-SA 4.0 · Wikimedia Commons
Phalaenopsis roots should be firm and green or silvery, never brown and hollow.
Phalaenopsis roots should be firm and green or silvery, never brown and hollow. Photo: André Karwath aka Aka, CC BY-SA 2.5 · Wikimedia Commons

How to prevent root rot

  • Water only after checking the soil, not on a fixed schedule.
  • Always use pots with drainage holes; empty saucers and cover pots 15 minutes after watering.
  • Match the mix to the plant: airy for aroids, gritty for succulents, bark for orchids.
  • Move up only one pot size (about 1–2 in wider) when repotting.
  • Water less in winter and keep plants above about 60 °F.
  • Replace old, compacted potting mix every 1–2 years.
  • Clean pots and tools before reusing them.

Common problems and fixes

Plant wilts even though the soil is wetClassic root rot sign. Check the roots right away instead of watering again.
New pot, still yellowing a week after rescueSome leaf loss is normal while roots regrow. Keep watering lightly and wait for new growth.
Rot came back after repottingUsually the cut was not deep enough or the pot stays too wet. Repeat the cut, use a smaller pot and a more open mix.
White mould and fungus gnats on the soilThe surface stays too damp. Let the top layer dry fully between waterings.

Frequently asked questions

Can a plant recover from root rot?

Yes, if some firm, healthy roots or stems remain. The earlier you act, the better the chances.

Can I just let the soil dry out instead of repotting?

For very mild cases it can work, but rotten roots do not heal. If the roots smell or feel mushy, cut them out and repot.

Is root rot contagious to other plants?

The fungi spread through water, soil and tools. Keep the plant apart, do not share saucers, and disinfect tools.

Should I use cinnamon or charcoal on the cuts?

They are popular home remedies, but evidence is limited. Clean cuts, drying time and fresh mix matter much more.

How long until I see new growth?

Usually 4–8 weeks (estimated), depending on the plant, light and season.

Plants prone to root rot

Snake PlantZZ PlantEcheveriaOrchidFiddle-Leaf FigPeace lilyAloe VeraPothos

Sources

Last updated: 2 November 2026