What Is Root Rot? And How To Treat It

Root rot is a disease that can have a devastating effect on plants if left untreated. In most cases, the damage it causes is irrevocable, with the affected roots turning black or brown and losing their naturally firm consistency. Root rot is the most common cause of root decay, after honey fungus, which can be equally as problematic.

If you think that your plant is suffering from root rot, don’t worry! It is possible to keep the disease spreading at a limit if you identify and treat the signs of rot at an early stage.

So exactly what is root rot?

In order to understand what root rot is, we must first understand what its causes are. There are two main reasons why a plant may become impacted by the disease.

The first and most common reason is due to overwatering. All of us, at some point or another have been guilty of being a little overzealous when watering our plants. Perhaps we were even unaware of the plant’s optimal condition requirements.

Either way, overwatering can be incredibly dangerous for a plant, especially if it has been planted in a poorly-draining container or similar outdoor conditions. This can result in the roots decaying or rotting due to a lack of oxygen, which may then be passed onto healthy roots.

The second cause of root rot can be due to the existence of a fungal-like organism in the soil. Also known as Phytophthora root rot, the species can impact both garden and houseplants. These organisms are capable of lying dormant for years without the presence of a plant, but can appear when the soil becomes waterlogged.

What Are Symptoms Of Root Rot?

It can sometimes be a little tricky to identify whether your plant is suffering from root rot because the majority of the issue takes place below the surface level.

Plants affected by root rot can often appear wilted with yellow leaves. This occurs due to the plants being unable to absorb moisture and vital nutrients.

If you look at the plant at root level, you will be able to notice which parts of it are healthy or unhealthy. Diseased roots will appear to be black or brown and soft. Many smaller roots will also drop off, leaving the larger roots turning a brownish colour.

Please note that healthy roots should be white and sturdy, so if you notice roots changing colour or consistency your plant may be suffering from rot.

How To Prevent Root Rot

There are several preemptive measures you can take to prevent root rot from forming. By taking a look at the specific requirements of each plant after purchasing and planting, you can identify how to best care for it. Best practices indicate that you should keep your soil as dry as possible between watering. You can also turn the soil to ensure that moisture leaves it completely before watering once again. To improve the soil draining capability, you can also introduce more organic matter or build beds on a raised platform.

If you notice that your plant is already exhibiting signs of root rot, there are a few steps you can take to prevent it from spreading further.

For both garden and house plants we would recommend unpotting them and brushing off any excess soil that surrounds the roots. The plant can then be gently washed to expose damaged and healthy roots. You can then take a sharp knife or gardening scissors to cut away any blackened or brown roots, just below the remaining healthy parts.

Once sufficiently pruned, you must aim to replant within a few hours in fresh well-draining soil that is not overwatered or extremely soggy. Please remember to sterilize your pruning equipment in a diluted bleach solution to prevent the spread of the fungal organism to other plants.

You can also use fungicidal root rot treatment, but this is not recommended unless you are fully aware of the causes of rot in your plants. If you are considering using fungicides, it may be ideal to get a professional opinion and/or fungal testing for a proper diagnosis before resorting to chemical treatments. This is because certain fungicides are only effective for limited types of funguses. If the wrong product is used, you risk causing more damage to your plants than helping them overcome rot.

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