PPO > Sudden Oak Death Research and Education Program > Sudden Oak Death > Information for Nursery Professionals > Managing Phytophthora diseases in the nursery > Incoming Plant Material > Questions to determine the likelihood of P. ramorum infection

Questions to determine the likelihood of P. ramorum infection

  1. The plant displays leaf blight, defoliation, or stem dieback symptoms similar to those shown in these photographs.
    • Yes – go to 2
    • No – Sample can be discarded
  2. What plant is affected?
    • The plant is a camellia, rhododendron, pieris, kalmia, viburnum, or lilac purchased since 2002 – Submit sample
    • The plant is growing next to a camellia, rhododendron, pieris, kalmia, viburnum, or lilac purchased since 2002 – go to 3
    • None of the abov – unlikely to be P. ramorum. Sample can be discarded.
  3. Is the plant a known host of Phytophthora ramorum?
    • Yes – Submit sample
    • No – sample can be discarded

WSU Puyallup Research & Extension Center
2606 West Pioneer, Puyallup, WA, 98371-4998 USA
Last updated 9/24/2025