Root Rot

Marijuana Horticulture

by Jorge Cervantes

Identify

Root rot fungi cause roots to turn from a healthy white to a light brown. As the rot progresses, roots turn darker and darker brown. Leaf chlorosis is followed by wilting of the older leaves on the entire plant, and its growth slows. When severe, rot progresses up to the base of the plant stock, turning it dark. Root rot is most common when roots are deprived of oxygen and stand in un-aerated water. Soil pests that cut, suck, and chew roots create openings for rotting diseases t enter. Inspect roots with a 10X magnifying glass for signs of pest damage.

Control

Use fresh, sterile growing medium. Make sure calcium levels are adequate, and do not overfertilize with nitrogen. Keep pH above 6.5 in soil and about 6.0 in hydroponic mediums to lower disease occurrence. Control any insects, fungi, bacteria, etc, that eat roots.

Sprays

Sprays are not effective.