Root rot has to be one of the most dreaded plant diseases for people with plants. One minute your plant is looking healthy and lush, and the next minute the leaves are yellowing and you question yourself as a plant parent.
In the past I’ve killed several plants by allowing root rot to take hold, and being none the wiser.
What is Root Rot?
Root rot is usually caused by waterlogged soil or fungi. In houseplants overwatering is more often than not, the culprit. As new plant parents its hard to get watering right, and its normal to overwater your plants. You know that plants need water, and you want to provide them with what they want – but too much of a good thing is not always a good thing.
When roots sit in an oxygen deprived environment, like wet soil, they will drown. They lose their ability to support the plant and will die off. You wont always notice the plant is developing root rot because it starts under the soil, and by the time the plants leaves show symptoms, it may be too late.
As mentioned above, the cause it not always overwatering or waterlogged soils. Root rot may also be caused by a genus of micro organisms called Phytophthora. Phytophthora are considered a ‘water mold’  and thrive off wet environments, using up the oxygen in the potting mix that would otherwise be available to the plants roots.
How can I identify root rot?
Root Rot can be hard to identify as a you may think a yellowing leaf is just a natural process.
Unfortunately you cant see the roots rotting below the soil, so aboveground signs are all you can go off.
Yellowing leaves or smaller distorted leaves are the normal sign. If you know yourself to be an over waterer or your pot doesn’t have good drainage, then these symptoms should alert you to root rot.
Generally, roots should be a healthy white/cream colour. If you notice the roots are brown/reddish and soft, the roots have died. At times it may be hard to identify whether the root rot is caused by fungi or waterlogged soil, but the outcome is the same.
Can I fix it?
The answer is a cautious ‘Yes’
BUT only if caught in the early stages. Extensive root rot is hard, if not impossible, to treat.
If caught in time, follow these steps:
1. Remove the plant from its container.
2. Rinse off all the soil from the roots.
3. Identify the rotten roots.
4. Using a clean scissors or knife, cut off the dead roots. Making sure not to damage any healthy roots.
5. Clean the pot thoroughly (in case the cause of root rot is fungi, you don’t want it spreading).
6. Make sure your pot has drainage holes, use clean potting soil when repotting & use a well draining potting mix.
Remember that prevention is easier than treatment, and the best way to prevent root rot is to have a pot with good drainage and a soil mix that is well draining.
Every plant has different watering needs, so make sure to do research when buying and caring for your plant.
 – Washingston State University – Link
First Photo – Leon & George
Second Photo – Indoor Plant Addicts