DIAGNOSIS TABLE-DOUGLAS FIR, OAK AND PINE

DIAGNOSIS TABLES FOR DOUGLAS-FIR, OAK, PINE

Note: These tables list commonly encountered signs and symptoms and likely causes, but not every possible symptom or potential cause is noted. 

Douglas-fir diagnosis table

Description

Possible causes (not exhaustive)

Tree foliage is sparse, thinning
Tree foliage is turning light green, yellow, orange, or red

Whole tree appears to be dying

Top of tree is dying or dead

Branches are dying
Scattered branches are turning red

Woodpeckers are feeding on trunk; tree is losing bark

Foliage is thinning
Interior needles are being shed, cast
Branch tips are still green

Needle casts

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Oak diagnosis table

Description

Possible causes (not exhaustive)

Leaves are undersized and/or discolored and /or prematurely dropping

Moisture stress

Canopy/foliage appears thin, unhealthy

Leaves have irregular spots or splotches
Leaves may be curled and deformed

Oak anthracnose

Premature (mid to late summer, before fall) leaf drop

Moisture stress

Some branches have died back

Leaves are partially or completely eaten

Defoliators

Leaves are being eaten or skeletonized
Larvae are visible on leaves
Larvae may hang from trees on thin, white “thread”

Defoliators

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Pine diagnosis table

Description

Possible causes (not exhaustive)

Top of tree is dead or dying

Blister rust (5 needle pines)
Foliage is thinning
Interior needles are being shed, cast
Branch tips are still green

Needle casts/diseases

Whole tree is dead or dying

Tree foliage is turning or has turned from green to greenish yellow

Woodpeckers are feeding on trunk; bark is falling off

Bark Beetles

Pitch tubes are visible on trunk

Some branch tips are dead

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