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WSU Puyallup Managing Phytophthora diseases in the nursery

Incoming Plant Material

Keep diseases out of your nursery by purchasing clean nursery stock from a trusted supplier. Monitoring incoming plant material is especially important in Washington since most is grown out of state.

Click here to see photos of situations involving plant material in nurseries.

Check plant material for disease symptoms before integrating it into the rest of the nursery stock using this guide to symptoms of Phytophthora ramorum and look-alikes on important PNW host plants.

High risk hosts in Washington are Rhododendron, Camellia, Viburnum, Pieris, and Kalmia species. Recently Vaccinium and Gaultheria spp. have been found with P. ramorum. These hosts are sold and planted in large quantities and have been connected to outbreaks of P. ramorum.

If you suspect P. ramorum on plant material, isolate it from other host plants. This key will help you determine the likelihood of P. ramorum infection. You can submit a sample to the WSU plant clinic for analysis.

Symptom ID and Scouting -Presentation from the Best Management Practices workshops in 2014

Click here to view the most recent APHIS list of regulated and associated hosts for P. ramorum.

Lists of certified shipping nurseries for the Pacific Northwest:

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