The most common cause of root rot is from overwatering which can cause some of the roots to die due to a lack of oxygen. As the plants die they will start to rot. This can then spread to healthier roots and kill them as well, even if the soil conditions are put right.
How to spot root rot
As with all garden diseases, it is important to spot root rot early. With this disease, in particular, you will notice the plant slowly wilting and the leaves turning yellow. If you try to touch the plant, it will feel mushy and look black in colour.
Some roots may be black, but if they feel firm to touch there could be some salvaging them.
How to treat root rot
Root rot treatment is possible, but if you want to save the plant you must act quickly in order to give the best chance of survival.
Take the plant from the soil and wash the roots under running water. Be gentle and try to wash away as much soil as possible. Trim the affected roots with a sharp, clean pair of scissors along with some of the leaves, so the root does not need to support as many leaves.
For potted houseplants make sure the container has good drainage and only water the plant when the top of the soil is dry. Don’t fertilise the plant once it has started to re-grow, as this may stress it. Hopefully, your plant will recover from root rot and you will be able to enjoy it again.