Southern California
Tree Disease Library
Understanding pathogens and pests is critical to proper Plant Health Care. In Southern California, our unique climate—extended droughts followed by heavy winter rains—creates ideal conditions for specific diseases. Explore our definitive guides to identifying, treating, and preventing tree decline.
Oak Root Fungus
A destructive soil-borne fungus that attacks the root systems of Oaks, Sycamores, and other native trees.
Shot Hole Borer
An invasive beetle complex that farms deadly Fusarium fungus inside the wood of Sycamores and Oaks.
Anthracnose
A common fungal disease causing severe leaf blight and twig dieback, especially prevalent in cool, wet springs.
Scale Insects
Sap-sucking insects that attach to twigs and leaves, draining tree vitality and secreting sticky honeydew.
Aphids
Tiny, prolific pests that cluster on new growth, causing leaf curling, yellowing, and promoting sooty mold.
Bark Beetles
Destructive beetles that bore into the cambium layer of stressed trees, often introducing lethal fungi.
Root Rot
A deadly water mold that decays root systems in poorly drained or overwatered soils.
Powdery Mildew
A widespread fungal disease that coats leaves in a white, powdery dust, stunting growth.
Sooty Mold
A black fungus that grows on the honeydew secreted by aphids, scale, and whiteflies, blocking photosynthesis.
Suspect a Disease?
Early diagnosis is the key to saving mature trees. Our Certified Arborists provide expert diagnostics and customized Plant Health Care treatments.
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