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.
Browning or dieback is usually caused by weather-related stress, sometimes in combination with pests and diseases.
This article briefly discusses the most prevalent madrone disease problems, then offers a broader perspective on the health of this southern Oregon native.
Poisonous plants are a major cause of economic loss to the livestock industry. Two poisonous plants common to Oregon are poison hemlock and Western water hemlock. Ingestion of either by humans or livestock typically results in death.