Plants Killed by Sudden Oak Death
The Phytophthera ramorum fungus affects a wide variety of plants. For most plants, the disease is limited to leaf and stem damage, but it can be fatal in some members of the oak family (Fagaceae). The most susceptible species in California is tanoak (Lithocarpus densiflora).
Oaks in the Black Oak group are susceptible to Sudden Oak Death. California natives in the Black Oak group include:
Coast Live Oak (Quercus agrifolia)
California Black Oak (Quercus kelloggii)
Shreve Oak (Quercus parvula var. shrevei)
Canyon Live Oak (Quercus chrysolepis)
By contrast, the members of the White Oak group are not affected by Sudden Oak Death. California native trees in the White Oak group include:
Valley Oak (Quercus lobata)
Oregon White Oak (Quercus garryana)
Blue Oak (Quercus douglasii)
Plants that Spread Sudden Oak Death
There is a long list of plants that are infected by Sudden Oak Death. On most of these species, however, the fungus is not capable of creating spores and spreading to new plants. While many plants can be infected and even damaged, only a few species are capable of passing the disease along. For example an oak that is infected and dying of Sudden Oak Death cannot pass the disease to other trees.
Even though few plants are capable of spreading Sudden Oak Death, it is illegal to sell or move any nursery stock that is infected with Phytophthera ramorum. For this reason, all nurseries, including the North Coast Native Nursery, are inspected on a monthly basis. Our nursery has consistently been free of this disease.
Two plants that are known to spread Sudden Oak Death are California Bay Laurel (Umbellularia californica) and Rhododendron.