Humans help spread the disease when they transport infected plants, plant parts or infested soil.
Most “sick tree” problems can be traced back to underlying stresses that have reduced the tree's vigor, making it more vulnerable to diseases or insect pests.
Excessive summer irrigation of oak and madrone trees may promote fungal diseases such as the oak root fungus (aka armillaria root disease) and crown rot.
A guide for how to collect and where to get a sample analyzed for plant diseases.
Many landowners are unaware that a legal right is needed to use surface water and groundwater for irrigation purposes.