A new arrival first confirmed in juniper bushes at Upper Teesdale National Nature Reserve in the North Pennines in 2011 and in single specimens of Lawson and Nootka cypress at two sites in Scotland. It has since been confirmed in juniper plants in 15 sites in Cumbria in North-West England, at Glen Artney in Perthshire and six further sites in Scotland, in a nursery and a private garden in Devon and two private gardens in Cornwall in South-West England. Other juniper sites showing possible symptoms are being investigated but information is in short supply.
Visible symptoms on infected trees include dieback of the foliage and stem and collar lesions. The root/collar infection can be observed by removal of the outer bark, revealing a necrotic, often cinnamon brown. When roots and collars/stem bases are affected, the foliage of infected trees turns a lighter colour than that of healthy trees. Later the foliage withers and turns brown, concurrent with drying and darkening of the inner bark.
Disease symptoms caused by P. austrocedri can be confused with other infections, including those caused by other Phytophthora species, such as P. cinnamomi, which is already present on a range of plants in the UK and around the world.