Gardeners at a historic estate in Derbyshire, England, have discovered the disease sudden oak death on rhododendrons, and fear that it could spread to ancient trees on the estate. Sudden oak death has been found at over 500 sites in England. English oak (Quercus robur) does not appear to be harmed by the disease. However, many other trees common in England are susceptible, including beech and conifers. The disease has been found mostly in rhododendrons, azaleas, viburnums and camellias in England. In 2004, a significant outbreak of the disease was found in Wales on holm oak, Quercus ilex. In the US, thousands of trees have been killed by sudden oak death, caused by the fungus Phytophthora ramorum, prompting an aggressive response to the disease by British authorities.
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