This spring my blue oak tree’s leaves are changing to reddish brown and falling off. What is happening?

Both prolonged drought and a leaf disease called anthracnose (highly infectious during very wet years) can cause early leaf drop, especially in blue oaks, but also in other oak species. So, a single year of early leaf drop is almost never problematic.  Leaves should reemerge next year.  You may observe some die back of a […]

My redwood has severe dieback and is near a coast live oak with SOD. Could the redwood have SOD?

Most likely the redwood is experiencing symptoms related to cycles between drought and rainy periods. However, if there is a significant presence of California bay laurels intermixed with redwoods, there may be enough pressure from the SOD pathogen to also cause problems on redwoods, both native and exotic. Any SOD oak infections are likely directly connected to […]

What can cause leaf tip scorch on redwood trees?

Leaf tip scorch symptoms on redwood trees are found from the lower to upper canopy and include healthy leaves interspersed with brown and grey leaves or portions of leaves. Grey leaves typically have black margins into the healthy tissue. Such symptoms are typically caused by a fungus called Pestalotiopsis funerea. They are commonly associated with […]

Bark beetles are attacking my oak. Will they kill the tree? What should I do?

Once bark beetles attack the main stem (trunk) of an oak, the tree is on its way out.  Insecticide treatments will not save it. Oak beetles are attracted to trees that are severely compromised.  They cannot attack healthy trees. The correct approach to avoid bark beetle infestations is not to apply insecticides, but rather to […]

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