Treating Root Rot in Indoor Potted Plants


When left unaddressed, treating root rot can be difficult to do. Root rot, which is common in indoor plants, can leave plants severely damaged. However, there are ways to spot root rot early, treat it, and even prevent it from occurring.

What Is Root Rot?

Treating Root Rot

Root rot is exactly what it sounds like: rotting roots. Root rot can spread quickly to the rest of the plant and prevent nutrients from being transported. If your plant’s leaves are turning yellow and slowly wilting for no apparent reason, it’s probably suffering from root rot. Affected roots will look like brown or black mush that easily fall off.

There are two possible sources of root rot: one is overwatering, causing roots to die due to lack of oxygen. Another is a fungus in the soil.

In cases of overwatering, your plant suffers a slow death as the roots drown. When the roots suffocate, they can start decaying or rotting away, spreading to other healthier roots. Pathogens can then attack the weakened roots and eventually kill the plant.

Alternatively, fungi can be triggered by overwatering, transmitted by bugs, or may already be living in contaminated soil. These fungi attack the roots and cause the plant to decay.

Two common fungi can cause root rot:

  • Fusarium:
Treating Root Rot fusarium
  • This is a common soil fungus that has multiple species. Roots and stems, especially those with cuts or lesions, are typically vulnerable. Dead or dying tissues are overtaken by Fusarium fungi, which is further exacerbated by overwatering.
  • Pythium:
Treating Root Rot pythium
  • This is a parasitic, bacterial organism that consumes decaying plant matter. Overwatering is also a common aggravator of this condition. Fungus gnats usually transmit Pythium. Recognizing and treating root rot early on will keep your potted plants in good condition.

Common Causes To Watch Out For When Treating Root Rot


As mentioned, overwatering is the most common cause of root rot. Typical symptoms include moldy flowers, yellowing foliage, and loss of young leaves. These symptoms are common when the damage is already extensive.

Factors that contribute to overwatering include:

  • Heavy, poorly drained soil: This soil tends to stay waterlogged and hardens like cement, not allowing water to drain correctly.
  • Not having adequate drainage: Pots and containers without drainage holes will keep water in the soil, eventually suffocating the roots.
  • Oversized pots: Having extra soil with empty space can become a soggy zone.
  • Non-porous containers: Plastic or glazed containers, unlike clay ones, can trap moisture instead of letting the soil breathe.
  • Cold temperatures: Overwatering can happen during the cold season because of condensation due to slower evaporation rates. Water consumption for plants is also higher during this time, which lessens the risk of overwatering.
  • Burying the stem: While this doesn’t apply to every plant, burying the stem too deep can invite decay for some plants.
  • Poor air circulation: Soil can become soggy when air is stagnant. Stagnant air can arise from crowding plants too closely, leading to poor ventilation and prolonged wetness in soil.
  • Off-season watering: Some plants undergo slow growth during certain seasons and may require less water. Not being able to adjust to their seasonal needs may lead to overwatering.

Tainted Garden Tools

Disinfecting your garden tools eliminates the risk of your indoor plants contracting an infection from your equipment. Always sterilize your shears, trowels, and even your pots so healthy plants don’t get sick.

Not Isolating Sick Plants

Much like people, sick or infected plants need to be isolated or quarantined to avoid infecting others. While you might not have a sick indoor plant, buying a new one can affect the ones you already have. If you notice plants with wilted leaves or puffy stems, keep them away from other plants until treated.

Stress is Also a Factor When Treating Root Rot

Getting stressed is another attribute plants share with humans. Aside from overwatering, too much or too little fertilizer can stress out your plant. Physical damage, improper lighting, drought, or other factors can also contribute to stress. Keep your plants happy and healthy, so they won’t be susceptible to root rot.

Contaminated Soil

You might not know it, but pathogens are present in most soil. They only need the right conditions to flourish. Avoid recycling soil from your garden without sterilizing it first. You can opt for commercial mixes, which are often sterile but don’t combine them with compromised soil. To prevent contamination, store potting soil in an airtight container.

Root Rot Signs and Symptoms

Root Rot Signs and Symptoms - treating root rot

Spotting the signs and symptoms early is essential in treating root rot. Depending on the severity of your plant’s condition, signs will manifest in different ways. Unfortunately, the initial symptoms might not be as noticeable.

The first signs you should watch out for are yellow or wilting leaves. Typically, bottom leaves will wilt first, followed by the rest. This is because the disease spreads from the bottom up. When leaves curl during the day and recover overnight, you likely have a problem. Slow growth is also a symptom of struggling roots. Another indicator of early root rot is soil that constantly stays wet.

If the root rot progresses, your plant will start showing mushy or swollen stems. When you notice this happening, examine your plant by gently removing the topsoil. If the roots are still white and crisp, you have nothing to worry about. But if they start becoming limp or turning yellow, that means the disease may be at an intermediate stage. A particular odor will also arise from a plant suffering from root rot. Healthy roots often have an odorless or earthy scent. If you start noticing an unpleasant smell from your plant, consider taking steps to treat root rot.

If these symptoms have eluded you, your plant is bound to suffer from an advanced infection. This takes the form of mushy, black or brown roots. Late-stage infections can also cause stems to come off when touched.

What To Do When Treating Root Rot


How you’ll be treating root rot will depend on how mild or severe the disease is. If you’ve detected the initial symptoms of root rot, observe your plant and hold off on watering. Often, simply letting the soil dry can be the solution to mild infections.

If you find fallen material or mulch on the topsoil, remove it to improve evaporation and proper air circulation. Excess moisture encourages the development of pathogens. Therefore, it’s important to remove any contributors to this condition. If there’s a lack of proper airflow, take the plant out of the soil to dry it out. This will also give it extra oxygen.

However, if the root rot is already in its later stages, consider repotting your plant. You need to do this gently so as not to aggravate the roots.

Here are the steps you can take:

  • Use barely moist, sterile potting soil during repotting to prevent further fungal attacks.
  • Remove the plant from the current pot and the soil from the root ball. Use running water to wash the roots and remove excess soil. Handle the roots with extra care.
  • With sterilized scissors or shears, trim away all the remaining rotting roots. Because the disease is in its late stages, you may need to remove a significant portion of the roots. Then, prune back a third to half of the plant’s leaves to support future growth.
  • Throw out the rest of the original soil. Sterilize the pot with one part bleach mixed with nine parts water to kill any bacteria or fungus. Add drainage holes to the pot or choose a different one if the original post doesn’t drain well enough.
  • Dip the roots in a fungicide solution. Then, repot the plant using the sterile potting mix.
  • Place the pot in a bright location and water only when the topsoil becomes dry. However, keep it isolated for a few weeks for further observation.

If the disease returns, this means you were unsuccessful in treating root rot. In this case, dispose of the plant and prevent it from coming in contact with other plants. Don’t forget to sterilize the pot again, as well as other garden equipment used. Discard the soil.

Treating Root Rot Through Prevention

Take preventative measures to avoid repeated instances of treating root rot. Here are simple but crucial steps you can take:

  • Make sure your pot has proper drainage.
  • Keep a routine watering schedule. Take note of the seasons and adjust accordingly to promote evaporation and airflow.
  • Constantly check on the plant’s soil. Make sure the top 2 inches are dry before watering to avoid oversaturation.
  • Aerate the soil to loosen it up so it can get ample oxygen, preventing moisture buildup in your plant’s roots.
  • Use sterilized soil that drains well. Avoid compact or heavy soils that tend to keep high moisture levels.
  • Use the right size pots or containers to avoid empty soil that can become waterlogged zones.
  • Make sure your plants don’t live in stagnant or contaminated conditions.
  • Be picky with your plants. If you choose plants susceptible to root rot, like succulents, make sure you’re aware of their needs. Otherwise, choose plants that might favor more moist conditions.
  • Be observant. Again, treating root rot is easiest when you spot early signs and symptoms.

Frequently Asked Questions About Treating Root Rot

This is possible if a store sells you a plant that’s already suffering from root rot. Always quarantine new plants for a few weeks to watch for signs of a problem.

The presence of fungi can definitely cause root rot. The two most common are fusarium and pythium fungi. Fusarium fungi typically attack roots and stems with cuts or lesions. They take over dead or dying tissues and the condition worsens with overwatering. Pythium fungi, on the other hand, are parasites transmitted by fungus gnats. This type of fungus consumes decaying plant matter.

Slowly wilting or yellowing leaves can indicate early root rot. Soggy or oversaturated soil is also another common sign. Severe root rot manifests most clearly when white, crisp roots have become limp, black, or brown mush.

Treating root rot depends on how far the disease has progressed in your plant. If you manage to stop the initial signs and symptoms of root rot, there’s a chance you can save your plant.

However, if the issue remains unaddressed for too long, the disease can spread out to the entire plant. In its intermediate stages, treating root rot may necessitate repotting the plant. Do this gently so the plant won’t experience unnecessary stress.

It’s too late to treat root rot when the roots have become black or brown mush that fall off. Similarly, puffy stems falling off in your hand are also a sign of severe root rot. You can still try repotting, but if the rot returns, throw away the plant to prevent further contamination.

The most common cause of root rot is overwatering. This happens because of several factors:

  • Using heavy, poorly drained soil
  • Not having adequate drainage holes for your pot
  • Oversized pots
  • Using non-porous containers
  • Changes in temperature
  • Burying the stem too deeply
  • Poor air circulation
  • Off-season overwatering

Other contributors include contaminated garden tools and soil, sick plants coming into contact with healthy plants, and plant stress.

Root for Your Roots

Root rot is a serious issue that you can prevent if you give your plant constant care and attention. Avoid treating root rot altogether by taking appropriate measures to prevent overwatering, which is the main cause of this disease.


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