Published in the Contra Costa Times on March 20, 2004

Q.  I want to plant camellias. Will they give my oak trees sudden oak Death?

A. Camellias have been identified as foliar hosts for Phytophthora ramorum, the pathogen that causes the disease known as 'Sudden Oak death'  A foliar host is a plant on whose leaves the pathogen lives and reproduces, producing  sporangia which  can spread to other plants including some Oak trees. Foliar hosts are rarely killed.  There are only a few plants that appear at this time to be killed by this organism, but the list of foliar hosts keeps expanding.  The most current information is available at http://www.suddenoakdeath.org/

 The pathogen has been found on the leaves of a few camellias in nurseries in California, Oregon and Washington. Pictures of what the diseases looks like on camellia leaves can be seen at the web-site listed above. Do not purchase plants that exhibit any of the symptoms, including leaf spots.  The agriculture department is actively removing all infected plants to control the spread of this disease, but gardeners should still be very careful.

The most important part of your questions refers to planting camellias near Oak trees. Camellia plants like moist, well-drained soil in a part-shade environment. Our native oaks do not like soil that is moist during the dry months within their drip-line. The drip-line is the area under the canopy of the tree, and a mature Oak has a very large canopy. Do not plant camellias under oaks. Camellias will do best if planted on the north-northeast side of a house with bright but not direct light. They can also be planted under non-native trees that prefer summer moisture. Camellias also like soil pH's that are relatively neutral. If you live in one of the areas of the county with high soil pH, you will need to amend your planting bed with a highly organic, acidic mix. You should provide regular water throughout the dry months unless you live in an area with regular summer fog. Water need to cover the entire root zone area. If you are using drip, use microemitters or inline soaker tubing. The soil needs to be moistened to an 8-12" depth each time you water and the soil under the canopy should be mulched to a 3-4" depth. Shredded leaves or bark are ideal.