Root Rot: Identify It and Save the Plant

Root rot is the single most common way houseplants die, and it is almost always survivable if you act early. The problem is that it happens underground — by the time the leaves tell you, the roots have been in trouble for weeks.

The counterintuitive signal

A plant that is wilting in wet soil has root rot until proven otherwise.

This trips people up constantly. Rotted roots cannot absorb water, so the plant droops exactly as it would if it were parched. The natural response is to water it, which accelerates the rot.

So: before you water a drooping plant, feel the soil. Wet soil plus wilting means stop watering and unpot it.

Signs, in order of appearance

1. Soil stays damp more than a week after watering
2. Lower leaves yellow, several at once
3. The plant wilts despite the soil being wet
4. Stem or leaf bases feel soft or squashy at the soil line
5. A sour, swampy smell from the pot
6. Leaves drop; stems collapse

By stage 4 you should be unpotting immediately, not waiting.

Confirming it

Tip the plant out of its pot and look at the root ball. You are checking two things — firmness and smell.

	Healthy	Rotted
Colour	White, cream, pale tan	Brown, grey or black
Texture	Firm, springy	Soft, slimy, mushy
When tugged	Resists or snaps	Outer layer slides off, leaving a thread
Smell	Clean and earthy	Sour, swampy, sewage-like

Firmness is the reliable test. Some species naturally have darker roots, so colour alone can mislead.

The rescue

Work over newspaper and take your time.

1. Remove all the old soil. Shake it off and rinse the roots under lukewarm water until you can see what you are dealing with. That soil is saturated and full of pathogens — none of it goes back in.

2. Cut away everything rotted. Use clean, sharp scissors. Remove every soft, brown or slimy root, cutting back into firm healthy tissue. Be ruthless: leaving rotted material behind restarts the whole process. Wipe the blades with rubbing alcohol between cuts.

3. Reduce the foliage to match. If you removed a third or more of the roots, remove a comparable amount of top growth. The remaining roots cannot support the whole plant, and cutting back gives it a fighting chance.

4. Let the cuts dry. For succulents, cacti and thick-rooted plants like ZZ and snake plants, leave them in open air for 24 hours so the cuts callus. For thin-rooted tropicals, an hour is enough.

5. Repot into fresh, dry mix. Not damp — dry. Choose a pot only slightly larger than the reduced root ball, with drainage holes. Add perlite or bark to whatever mix the species prefers.

6. Wait before watering. A week for most plants, up to two for succulents. Then water lightly and let the mix dry further than usual before the next round.

What to expect afterwards

Recovery is slow and looks unimpressive. The plant may drop leaves for several weeks as it rebalances to a smaller root system. Growth stalls. This is normal.

Watch for new growth as the sign it has taken. That can be one to three months in.

When it cannot be saved

If the entire root system is mush and the stem is soft at the base, the plant is gone. Rot travelling up into the stem does not reverse.

Salvage what you can: cut well above any softness into clean firm tissue, and root the top as a cutting. Many houseplants — pothos, philodendron, monstera, rubber plants — root readily in water, and you effectively restart the same plant.

Preventing the next one

• Drainage holes, always. A pot with no drainage is the leading cause. Keep plants in plastic nursery pots inside decorative cachepots and lift them out to water.
• Empty the saucer. Never let a pot stand in collected water.
• Right-size the pot. One to two inches wider than the root ball. Excess soil the roots do not occupy stays wet for weeks.
• Check before watering. Finger two inches in. Damp means wait.
• Cut back in winter. Most plants slow down and need dramatically less water from November through February. Watering on a summer schedule through winter is a classic route to rot.
• Match the mix. Succulents and cacti want gritty mix. Aroids want bark and perlite. Bagged potting soil alone holds too much water for most houseplants.