How to Manage Pests

Damping-off diseases—Pythium and Rhizoctonia spp.

Several soilborne fungi, including Rhizoctonia spp. and water molds such as Pythium, thrive under wet soil conditions. Infected roots become soft, mushy, darkened, and decayed. Water mold fungi also cause "damping-off," the death of seedlings that collapse at the soil line under damp conditions. More mature plants infected with Pythium grow slowly and may gradually decline, exhibit terminal dieback, and die.

Solutions

Prevent damping-off diseases by preparing the site well before planting and providing appropriate cultural care, especially proper irrigation. Solarizing the soil before planting can reduce Pythium and Rhizoctonia fungi.

Browning and death of shoots caused by Pythium. This bare root rose developed damping off disease after cold storage and excessive moisture.