Port Orford cedar root rot
Phytophthora lateralis
21 host plants · Oomycete
Last updated
Port Orford cedar root rot caused by Phytophthora causes decline and death of this valuable native species. Avoid moving soil or plant material from infected areas. Improve drainage where possible. Do not replant susceptible species in infested soils. Select resistant alternative species for affected sites. Proper drainage and good site selection are critical to prevent root disease problems. Monitor plants for early signs of decline or wilting.
Root rots thrive in waterlogged soil, so drainage is your most important intervention. Avoid overwatering and ensure the planting site drains well. Remove severely affected plants to prevent spread to neighbors through root contact or contaminated soil. When replanting, choose resistant species or improve soil structure before putting anything back in the ground.
Quick Reference
Management
Cultural Controls
- Avoid moving soil, water, and equipment from infested areas to clean sites; this is the primary source of spread. Do not move plants or nursery stock from infected locations without certification.
- Plant on well-drained slopes where water drains away from the site naturally. Avoid low-lying areas and sites prone to flooding or water pooling.
- Avoid planting in areas with poor drainage or where roads drain water. Do not plant downslope from infested sites.
- Plant at the same depth the tree grew in the nursery; do not plant too deeply, which can promote root collar rot.
- Avoid waterlogged conditions; water carefully and do not allow standing water around the root crown.
- Improve soil aeration by amending with composted bark or sawdust if planting in heavy, poorly drained soil.