Phytophthora Root Rot
Symptoms and damage
Leyland cypress is susceptible to the root-rotting fungus Phytophthora. Root rot is
primarily a problem in soils with very poor drainage. Young plants are most
often affected. Mature, established trees are seldom affected. Phytophthora species that cause root rot live in
the soil and enter a healthy tree through wounds or the succulent parts of
small roots. As the fungus destroys the roots, symptoms of distress become
apparent above ground. Foliage becomes stunted, sparse, changes color (yellow,
purple, tan) and dies. Cankers may be visible at or below the soil line.
Remove and destroy infected
plants including the entire root system. There is no practical chemical control
for home gardeners. Improve soil drainage by adding organic material to heavy,
clay soils and avoid overwatering. If replanting, do not plant a Leyland
cypress or other susceptible species where Phytophthora is known to be present.
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