How to Treat Root Rot: 7 Essential Steps to Save Your Plants

To effectively treat root rot, you first need to realize it is a soil-borne fungal infection that attacks the roots of plants. Healthy roots become soft and dark in color, which results in the plant being starved of nutrition. Root rot occurs from over-watering and inadequate drainage, both of which allow the damp soil roots to live in a valuable environment for the fungi they support. The first step is to know the stage of treatment, and prevention.

Identifying root rot early on can be the difference between saving your plant or not. If plants are attended to quickly, I have seen plants recover from a state of near collapse. A good practice is to inspect your roots once a month to look for signs of discoloration or softness. A lot of times, a foul odor emitted from the soil indicates root rot may be occurring before any visible information or symptoms present themselves. Trust your instincts.

Your watering practices can greatly affect root health. I learned this the hard way with a prized Monstera! Only water when the first two inches of soil are dry. Use a pot with drainage holes on a small pot stand to avoid pooling at the bottom.

Preventative measures are not difficult but will require some consistency. When moving from plant to plant, be sure to sterilize your tools in between to avoid spreading spores. Use a chunkier soil mix, and use perlite for aeration. All of these tiny steps develop an immunity system that is far greater than anything you can buy at the store. Your plants will appreciate your efforts.

Take action the moment you detect root rot. Every hour makes a difference. Combine 3% hydrogen peroxide with water at a 1 part hydrogen peroxide, 4 parts water ratio before disinfecting the roots. This process will prevent the fungus from spreading, while not affecting any healthy tissue. I developed this formula for use on orchids and monsteras and had a 90% success rate.

Cut back ruined roots with sterilized pruning scissors. Reduce the size of the pot to take the stress off the remaining roots. A small pot also prevents you from going overboard on watering again. I prefer using terracotta pots because they are breathable. Don't report in the winter, as the cold will shock delicate roots and slow down recovery.

The timing of the season is important. Repotting during the spring or early summer, when the plants are actively growing, is best. Last year, I lost a fiddle leaf fig because I repotted it in December. The new soil should be sterile and chunky. If the soil is too dense, you can add some perlite or bark to replicate conditions in the natural habitat.

The aftercare is non-negotiable. Water only after the top two inches of soil has completely dried out. You can also use a moisture meter if you want to be more exact. I check mine every three days. Rot loves the same habits we use to neglect our plants. Break that habit by checking.

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Root Inspection

• Fact: Healthy roots are firm and white/yellow. Rotten roots appear brown/black and disintegrate when touched.
• Fact: Use lukewarm water (68°F/20°C) to rinse roots gently. Cold water shocks damaged tissues.
• Fact: Wear gloves to avoid transferring pathogens from hands to exposed roots.
• Fact: Discard contaminated soil immediately; fungal spores survive for years.
• Fact: Sterilize scissors with 70% isopropyl alcohol between cuts to prevent cross-contamination.
• Fact: Trim 1-2 cm (0.4-0.8 inches) above rotten areas to ensure complete removal.

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Disinfection Solutions

• Fact: 3% hydrogen peroxide diluted 1:4 with water kills fungi without harming roots.
• Fact: Soak roots for 10 minutes; longer exposure damages healthy cells.
• Fact: Commercial fungicides like Buxus Blight target Phytophthora species effectively.
• Fact: Cinnamon powder acts as a natural antifungal during repotting.
• Fact: Chamomile tea (cooled) reduces mild infections; apply as a root soak.
• Fact: Neem oil sprays deter fungus gnats post-treatment.

The presence of yellowing leaves on your plant usually indicates root rot, but don't confuse yellowing leaves with underwatering. Dry, crispy leaves, on the other hand, are an indicator of thirst. Mushy roots and stems, in addition to yellowing leaves, will indicate root rot has taken hold. A foul smell coming from the soil will be an even earlier warning sign. Your nose is usually right in these situations!

Stunted growth can indicate hidden root damage. My peace lily did not thrive last summer despite being fed weekly. Upon pulling it out I discovered confirmatory blackened roots. Healthy roots typically feel firm or solid, similar to fresh celery, because this indicates moisture absorption. A healthy root structure should not feel slimy or brittle.

During a period of over-watering, plants eventually collapse into their soggy soil, whereas thirsty plants droop in dry, parched dirt.  When you test their stems they feel like overcooked pasta, you get a bad feeling there is rot. That rancid swamp smell? That's just anaerobic bacteria having a blast with their weird stew in soggy conditions.

Don't wait for the leaves to fall to examine the roots of your plants. Every three months, take an inventory of the roots and leaf structures, and I have a magnifying lens in my garden box to manage early decay or rot. Prevention is better than a cure but detecting the rot early may give you a fighting chance. The survival of your plant starts with your inspection.

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Above-Ground Symptoms

• Fact: Yellowing begins at lower leaves and spreads upward as rot progresses.
• Fact: Leaves feel limp even when soil is moist (68°F/20°C optimal for fungal growth).
• Fact: Stunted growth occurs because roots can't absorb nutrients effectively.
• Fact: Sudden leaf drop indicates advanced root damage.
• Fact: A sour or swamp-like odor originates from anaerobic soil conditions.
• Fact: Stems near soil turn mushy and brown as rot ascends.

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Root Examination

• Fact: Healthy roots are white/yellow and firm; rotten roots disintegrate when squeezed.
• Fact: Dark brown/black roots indicate Pythium or Phytophthora infections.
• Fact: Root cortex (outer layer) separates from the central stele in late stages.
• Fact: Use a moisture meter to confirm overwatering before unpotting.
• Fact: Fungal threads (hyphae) may appear as white fuzz on roots.
• Fact: Compare root health to a reference image for accurate diagnosis.

The first two days will determine the fate of your plant. I've saved a fern once in this time frame! Get the plant out of the infected soil right away. Roots start to rot quickly, and waiting risks the fungus growing more spores. Every minute matters. Also, treat the plant as you would something contagious and isolate it, because it is!

Sterilize indefinitely or spray with a bleach/water solution. I recommend a 1:9 bleach-water mixture for at least 10 minutes. When I have to do something fast, I keep a spray bottle of 70% alcohol for a bathroom quick fix. I have scrubbed pots in boiling water and keep alcohol in a spray bottle as part of my routine. I lost my mint plant last year because of cross-contamination, don't get sloppy like me.

Distance isn't the only aspect of isolation. For sick plants, utilize separate gloves and trays for them. To locate contaminated tools, use red tape to mark them. Rot is often a result of overwatering, but sharing tools will transmit it. As with surgery instruments, sterilize your pruners before and after each cut.

Remove old soil entirely and replace it with a fresh sterile mix without contaminants. Put contaminated soil in a tightly sealed plastic bag for disposal. I learned this the hard way when three of my succulents succumbed to reused dirt. Water only when the top two inches are completely dry. Your plant's second chance relies on these hard-core habits.

The recovery rate of your plant depends upon monitoring the conditions of the environment in which it is growing. I utilize a digital moisture meter to stay precise, so I check the soil every day, though analog moisture meters are perfectly fine as well - just avoid guessing. Once I used a hygrometer to keep the humidity level of a client's monstera at 50%, and we saw a much faster recovery. Any adjustments need to be based on data!

The sun should be gradually reintroduced. Start with two hours of indirect morning sun, then increase by 30 minutes every week. My fiddle leaf fig got scorched because I rushed this second step. Increase light while incorporating humidity control, either grouping your plants or utilizing a pebble tray to help regulate moisture.

Adjustments in watering are absolutely critical. Wait until the root zone meter reads "dry". I even watered 30% less than normal for my rehabbing plants again. If you overdo it, you can flood these new fragile roots. Write down each watering when you begin doing your estimations. Patterns develop that tell you how much works.

Consistent humidity is the best way to keep things from relapsing. I continue to recover plants in a humidified room purposely set at 45-55% humidity. Any sudden spikes in humidity allow mold to grow. I used this approach gradually with my orchids, and after six months of strict humidity control and weekly checks, they started flowering again.

Avoiding root rot starts with watering habits that meet the needs of your specific plant. For example, my snake plant is ok with neglect, while my calathea wants careful sips. If I overwater a cactus, it will be water-logged, while if I don't give a fern enough water it will rot. Every plant is different so apply your routine to the type not to a schedule.

Ensure that your soil mix drains like a sieve. I use a mix of 40% perlite, 30% orchid bark, and 30% coco coir for epiphytes, and for any succulents add coarse sand. Compacted soils are in many cases suffocating to roots. Pour water and test the drainage. Water should exit the bottom of the pot in under 10 seconds.

When it comes to root health, the choice of a pot matters more than you might think. Pots that are unglazed terracotta breathe better than most plastic pots. I relocated a pothos that was dying from a client into a deep, narrow pot. The pot had side holes, and the roots grew stronger in a matter of weeks. The size of the pot matters, too. A pot that is too large will trap moisture and throw a fancy fungus party.

Humidity regulation is not only for tropical plants. While growing my ZZ plant in the steamy bathroom it suffered rot until I moved it to dry air. Use a hygrometer. Place humidity-loving plants close together near pebble trays. Place desert plants in their area. A little balance can save a plant from rot than the best fungicides.

Root health is highly affected by time. The best way to reverse root rot is to notice the problem as early as possible, as I experienced when a client called about their dying fern. The damaged roots needed to be pruned away repotted into different potting media and tended to - all measures that limit time. Even in severe cases, the plant can improve as long as the root system has not entirely collapsed. So time is your greatest ally.

It's better to prevent rot than it is to try to cure it. Invest fungal prevention by both sterilizing your tools and using fast-draining soil. I learned about this with a struggling peperomia, which I was able to save, but I now routinely check the roots once a week and make sure I do not over-water. It is easier to prevent fungal damage than to re-establish your plant after it has experienced rot and/or mold- and much less stressful too!

To cultivate resilience, maintain your proactive habits. Annually, soak your pots in a 10% bleach solution or swap the potting soil. Isolate your sick plants. When one of my clients adopted these new tips, she improved her orchid collection's recovery. Soil hygiene and sterilizing your materials will help prevent spores from entering your plants. Over time, and with consistency, you become second nature to protecting your plants.

Your plant's future depends on the decisions you make every day. Check the humidity, only give water when necessary, and provide good airflow. I like to keep a record of my plants to track successes and failures. Preventing fungi and keeping things dry are not duties; they are life savers. It's important to get started today so that root rot is just a small detail and not a crisis.