Root rot

Using a dense potting media such as one dug up from outdoors can also cause root rot.

Many cases of root rot are caused by members of the water mold genus Phytophthora; perhaps the most aggressive is P. cinnamomi.

[citation needed] Root rot can occur in hydroponic applications, if the water is not properly aerated.

Root rot and other problems associated with poor water aeration were principal reasons for the development of aeroponics.

[citation needed] Some particular pathogens infect plants and causes root rot.