[Photograph]: Cedar trees along a river.Port-Orford-cedar, Chamaecyparis lawsoniana, has long been recognized for its characteristic beauty. In 1854, seed was collected from Port-Orford-cedar near the Coos Bay area and taken back to England for culturing as an ornamental. Many different cultivars of Port-Orford-cedar were developed and it became a very popular and widely used tree and shrub in landscaping in Europe and North America. The first signs of potential problems appeared when landscaping stock began dying in Seattle, WA, in 1923. The disease was a root-colonizing organism, identified in 1943 as Phytophthora lateralis, that quickly destroyed seedlings. In 1952, the disease was first found on native trees in natural forests. Port-Orford-cedar is limited in its natural range of habitat to northwestern California and southwestern Oregon. The disease has spread into many stands in both California and Oregon and can quickly kill all sizes and ages of Port-Orford-cedar in the forest.

Port-Orford-cedar has been an extremely valuable commercial species, both for its landscaping use and as a finished wood product. Individual mature Port-Orford-cedar trees can bring up to $50,000 on the open market. The Japanese highly prize the wood for use in their homes as it closely resembles their native hinoki cedar. Port-Orford-cedar is also an important species for traditional use to native Americans who inhabited the range of Port-Orford-cedar. It has been used in ceremonial houses and sweat lodges.


Port-Orford-cedar is found mainly along streamsides, bogs, and other wet areas in most of its range. It is an important component of these riparian zones as the long lasting wood provides persistent structure to these riparian areas for fish, amphibians, and other aquatic organisms. Port-Orford-cedar can be also be found on sideslopes and at higher elevations in some portions of its range. Phytophthora lateralis does not appear to be spreading as rapidly in these drier areas.

Phytophthora lateralis spreads via living spores in water and also via more durable long lasting spores, which reside in the soil. When soil which is infected with these spores is transported in mud on vehicle tires, boots, mountain bikes, logging trucks and equipment, and other off road vehicles to areas that are not infected, the disease can then establish itself and colonize any Port-Orford-cedar roots which it comes into contact with. If the disease infects any Port-Orford-cedar along streams, rivers, or any open body of water, the disease spreads rapidly to other Port-Orford-cedar downstream and within contact with that body of water.



There are many users of National Forests, Bureau of Land Management (BLM), and other lands within the range of Port-Orford-cedar. We are actively trying to educate the public on how the disease spreads and what can be done to help slow the spread. Contractors, loggers, road maintenance crews, trail crews, and many others all are required to take special precautions in their contracts. Work seasons are typically limited to the dry season and equipment is required to be cleaned before entering uninfected areas and when leaving infected areas. Signs have been posted on travel routes through Port-Orford-cedar stands and on gates which are closed for Port-Orford-cedar protection describing why it is important to pay attention to measures in place for Port-Orford-cedar protection.

Road Closures

Roads that access areas that are disease free are being closed during the rainy season or year round with gates or tank traps to lessen the risk of introduction of the disease.


Roads with little or no infection of Port-Orford-cedar next to the roadway are being cleared of Port-Orford-cedar to prevent establishment of the disease in trees next to the roadway. It is hoped that this will prevent spread of the disease downslope and downstream from Port-Orford-cedar stands directly adjacent to roads.


A program is underway to identify Port-Orford-cedar trees that are resistant to the disease. Thousands of individual trees have been collected from and tested throughout the natural range of Port-Orford-cedar. Other research is ongoing to determine how long the durable spores can survive in the soil under various temperatures and moisture content.


The effectiveness of treatments such as sanitation and road closures is monitored continuously. Roadside areas that have had Port-Orford-cedar removed are being tested to determine how long disease spores survive when the Port-Orford-cedar is removed. Contracts are monitored to determine if mitigation measures are being followed. Planned for this year is a range-wide assessment of Port-Orford-cedar to determine what proportion of cedar has been infected, the rate of spread of the disease, current status of research, identification of needed research, and a review of the effectiveness of current management.

What Can You Do?

  • Respect road closures and gates.
  • Find out the locations of root disease before traveling in the forest and take necessary precautions such as washing off your tires, wheel wells, and undercarriage prior to entering uninfected areas.
  • Avoid unnecessary travel across infected watersheds and on dirt roads when soils are wet.
  • Comply with permit requirements when collecting firewood, boughs, mushrooms, Christmas trees, beargrass, or other forest products.
  • Wash off when you have entered an infected area. Wash off muddy boots, tires and undercarriage of cars, trucks, 4 wheelers, motorcycles, mountain bikes, and other ORV's.
  • Don't remove any kind of seedling from infected areas for planting elsewhere.
  • Report dead and dying Port-Orford-cedar to local Forest Service or BLM offices.

If you have questions or comments concerning Port-Orford-cedar or the root disease which is affecting it, please contact Jeff Jones (707) 441-3553.