Drought hits Douglas-fir trees hard

By Mary Stewart
Many Oregonians have noticed widespread damage in landscape and forest trees this spring – and weather may be the culprit.
“Browning or dieback is often caused by weather-related stress, sometimes in combination with pests and diseases,” said Glenn Ahrens, a forester with Oregon State University’s Extension Service. Douglas-fir trees are the most common victims, he said, but stress due to weather is affecting many tree species and a variety of problems are showing up.
On some Douglas-firs, branches and tops are turning red or brown. Sometimes the entire tree dies. Older trees typically have milder symptoms.
“This sudden mortality or ‘flaring out’ of branches and tops is a classic symptom of drought in conifers,” Ahrens explained.