Do You Know What Galls Me? Cynipid Wasps!

Article

Have you seen those round, ball-like growths on oak leaves? Or the fuzzy moss-like unusual structures on rose stems? These are the results of a tiny parasitic wasp called a gall wasp or Cynipid. Galls...

What's killed my tree?

Article

Are you one of the many woodland owners noticing continued signs of drought on your property? Drought impacts are complex; drought stressed trees become susceptible to insects and diseases that are naturally present (typically at low levels) in our woodlands. Take these four steps to help you identify what factors might be impacting your tree health:

By Norma Kline

What’s Wrong With My Madrone?

Article

This article briefly discusses the most prevalent madrone disease problems, then offers a broader perspective on the health of this southern Oregon native.

By Max Bennett, Dave Shaw

Galls

Article

Galls are swellings or growths caused by the secretions of certain insects such as cynipid wasps.
Two people examining a tree

Douglas Fir Insect Pests

Article

The most common insects in the drought stressed or dead Douglas-fir.
Three people examining a pine branch

Diagnosis Table - Douglas Fir, Oak, Pine

Article

Diagnosis tables for Douglas fir, oak, and pine trees.
Three people examining a pine branch

Why Are My Trees Dying?

Article

Trees all over Douglas County are displaying signs of poor health. Most people are quick to blame insects, but while insects are almost always present in sick trees, they are rarely the underlying cause of the problem.

By John Punches

Three people examining a pine branch

Abiotic and Site Factors - Interactions with Insects

Article

Many if not 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.
Three people examining a pine branch

Summer Irrigation of Madrones and Oaks

Article

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.

Know Your Forest Learning Library

Online Resource

Looking for practical information about managing your forestland? You’ve come to the right place. We’ve put together an extensive library of resources to help you reach your goals.