PPO > Sudden Oak Death Research and Education Program > Sudden Oak Death > For those who work with Native Plants > Best Management Practices for Native Plant Nurseries > BMP for Native Plant Nurseries: Water

BMP for Native Plant Nurseries: Water

a stream with some plants in it
Many growers use water from an adjacent stream or river for irrigation. It is wise to treat this water before use, to prevent infection of crops with P. ramorum and other waterborne diseases.
saplings planted along a stream, each with their base covered in a plastic tube
Irrigating restoration plantings using stream water is risky if the plants are hosts and the water is contaminated. This is critical for Phytophthora spp. that cause root disease, such as P. lateralis and P. cinnamomi. While P. ramorum is not known to cause root disease, it can colonize the roots asymptomatically. The consequences of this is an area of research that needs further study.
plants in pots that show wetness on the outside. the leaves on the plants closest are gray with sediment
Sediment deposited on plants after flooding is one means of transmitting P. ramorum inoculum from water to foliage.
a man in a safety vest and rubber boots demonstrating how deep the water in an unexpected hole in the landscape can be
A high water table will create a flooded situation in an in-ground planting, increasing plant stress and potential for Phytophthora infection.

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