Washingtonia Fan Palms

Included in this are the native California Fan Palm which lives in our Southern California deserts. This palm Washingtonia filifera, does best in the dry desert areas of the region.  When planted in the coastal areas they are very prone to Diamond Scale Fungus disease. This disease is very difficult to control and frequently results in the death of these trees. Because of this problem is is recommended that landscapers use the Mexican Fan Palm or a hybrid of the two species as they are resistant to the diamond scale fungus disease. 

There is literature that points the the Wasinghtonia fan palms as being susceptible to Fusarium wilt disease. I have never seen this occur in the San Diego area. Washingtonia fan palms are also susceptible to pink rot in some circumstances. This is usually in cool wet areas. Treatment for pink rot, if made early in the infection, can be successful.