Maricopa County Cooperative Extension Home Horticulture:
Gardening & Landscaping in the Low Desert
Cotton Root Rot (Phymatotrichum omnivorum)
in the Low Desert
HOST: Only monocots (palms, grasses, bamboos, etc.) are immune, native plants seem to be more resistant.
- Infected plants suddenly wilt and die in the heat of the summer and the dead leaves remain attached to the plant.
- Infected roots have a distinctive fungal growth pattern which can be seen under a microscope as a cruciform pattern.
- Cortex pulls off easily (sloughing)
- Pancake batter-like spore mats (often confused with other harmless fungi) may appear on soil surface of infested areas, but do not spread the fungus.
The fungus lives in the soil and infects roots via wounds or natural openings.
For More Information see AZ1150 Cotton (Texas) Root Rot
Plant desert natives which are tolerant of the fungus or monocots (bamboos, grasses, palms) which are immune . There is no effective treatment. By the time symptoms are noticed the roots have already been destroyed.
To Gardening and Landscaping in Maricopa County, AZ
Cotton Root Rot (Phymatotrichum omnivorum) in the Low Desert
Last Updated July 7, 2006
© 1997 The University of Arizona,
College of Agriculture,
in Maricopa County.
Comments to Maricopa-Hort@cals.arizona.edu
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