Root rot. Two words no plant parent wants to hear. Whether you’re new to houseplants, or have been growing them for years, root rot is a common concern that can impact just about anyone. But what actually causes root rot? How can you treat it, and more importantly, prevent it? The answer might be easier than you think.

Root rot is the decay of a plant’s root tissue, usually triggered by overwatering, poor drainage, or compacted soil. While often blamed on fungi, it’s fundamentally an environmental problem. Spores are always present in healthy soil, but only turn pathogenic when environmental conditions favor them – similar to strep bacteria in humans. 

While all plants are susceptible to root rot, indoor plants are particularly vulnerable for two key reasons:

1. They get a lot less light than outdoor plants, which reduces transpiration– meaning water lingers in the soil longer.
2. They are at the mercy of human care, which isn’t always a good thing– chronic overwatering, poor drainage, or leaving pots in standing water all increase risk.

Identifying Root Rot

The most common signs are plants that wilt despite adequate watering or unexpected leaf drop. But these symptoms can also be signs of other challenges. The only way to confirm if a plant has root rot is to remove it from the pot, remove the soil and expose the roots. Healthy roots (for most species) are usually bright white or yellow, while rotted roots look much like the soil, are very brittle, and easily break when touched. 

Pro tip: For precision, weigh your plant when the soil is dry, then weigh it again a few weeks later. If the soil feels dry but the pot is still heavy, excess water may be trapped — a red flag for root rot.

Treating root rot: It’s all in nature.

So you’ve got root rot. Now what? Follow these steps:

1. Remove and clean. Take the plant out of its pot, wash away all of the soil and expose the roots.  If needed, use a hose with a pressure nozzle.
2. Get rid of the dead roots. Make sure you use your hands while performing this step. You should be able to feel the difference between healthy and rotted tissue.
3. Dry the roots. Pull the roots apart  and leave them exposed to dry air for a few hours. Because pathogens are anaerobic, oxygen helps eliminate them.
4. Repot. Place the plant in new soil in a new pot or the same pot that has been disinfected.
   
   Pro tip: When it comes to sterilizing, nature is your best friend. Wash your pot thoroughly, let it dry directly in the sun. Sunlight and oxygen will naturally sterilize the pot. Alternatively, you can use peroxide.
   
   
5. Avoid watering the plant after this procedure for at least one week. 

Another way to treat root rot is through competitive inhibition — adding beneficial fungi before harmful ones take over. Indoor mixes often lack them, but products with Trichoderma (a natural soil fungus) can restore balance and protect roots. Even better (and cheaper!,  a small amount of soil from a healthy forest floor can introduce protective spores that help the plant recover.

A third option is using diluted hydrogen peroxide (3% solution mixed 1:2 or 1:3 with water). Wash the roots, dip them in the solution, then let them dry before repotting. 

Pro tip: always dilute — concentrated peroxide can kill roots.

When it comes to prevention, environmental factors reign supreme.

Remember, while pathogens are at work when root rot happens, it’s a symptom of the plant’s environmental conditions. Follow these tactics to prevent root rot and ensure your plants are thriving:

• Don’t overwater your plant! Moisture meters have a short shelf life, but the finger test is usually reliable.
  
  
• The pot you choose is important.
  • • When choosing a pot, Terracotta is best for preventing rot thanks to its porosity, while glazed ceramic and other impermeable materials trap moisture.
    • Choose a pot that matches the volume of the plant. A pot that is too big may hold too much water.
    • Ensure your pot has a central drainage hole.
      
      
• Avoid overfertilizing. Too much fertilizer can feed pathogens that may already be present.
  
  
• Skip organic fertilizers indoors. They rely on soil microbes to break down their large, complex molecules before plants can absorb their nutrients– a process that takes months and rarely benefits houseplants.
  
  
• Stay away from chemical interventions. Avoid fungicides. Like antibiotics, they kill both harmful and beneficial microbes, leaving plants more vulnerable. Competitive inhibition with beneficial fungi is far more effective.

Root rot may be one of the most dreaded plant problems, but with the right diagnosis, treatment, and prevention strategies, it’s entirely manageable. By focusing on healthy soil, proper watering, and natural defenses, you’ll set your plants up to thrive.