PlantRoot rot.
Decay of roots caused mainly by oxygen starvation in waterlogged media and by opportunistic pathogens such as Pythium, Phytophthora and Fusarium.
What it means for your plants
Healthy roots are firm and white or tan; rotten roots are brown or black, mushy, and their outer layer slides off. Cut away all decayed tissue with sterilized tools, repot into fresh, airy mix, and water only when the top 2–5 cm is dry.
IN PRACTICE
A snake plant with yellow, collapsing leaves in cold, wet mix usually shows soft, blackened roots when unpotted.
Put it into practice
Root rot starts with oxygen-starved roots in wet mix and ends with Pythium or Phytophthora. How to confirm it, cut it out, save cuttings and stop it coming back.
Root rot in houseplants: diagnosis, rescue and prevention
