TILLAMOOK TREE SERVICE
🌲PACIFIC NORTHWEST PRUNING GUIDE🌲
A visual, arborist-led guide to when different trees should be pruned in our coastal climate.
Pruning timing matters.
Cutting at the wrong time can stress trees, reduce flowering, invite pests, or cause long-term decline.
This guide reflects PNW coastal rainforest conditions — not generic national advice.
✅ Ideal / Recommended ⚠️ Conditional / Light pruning only ❌ Avoid
🌙 What Is Dormant Season?
Dormant season is when a tree enters a natural resting phase:
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Growth slows
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Energy is conserved in roots and trunk
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Stress response is reduced
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In the PNW's coastal climate, true dormancy often does not begin until late December.
Trees can remain metabolically active through October and November due to mild temperatures and rainfall.
Pruning too early — even when leaves are gone — can still cause stress.
❄️ “It’s Winter — Doesn’t That Mean It’s Safe?”
Not always.
Just because a tree is leafless doesn’t mean it’s dormant.
In coastal Oregon, trees often:
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continue redistributing energy into late fall
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remain vulnerable to premature pruning
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respond better when fully at rest
We wait until trees are fully settled before major pruning.
🌲 Why Timing Differs by Tree Type
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Deciduous trees tolerate winter pruning best
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Evergreens don’t fully go dormant and need careful timing
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Spring bloomers must be pruned after flowering
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Fruit trees benefit from winter structure + summer thinning
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Ornamental pines require interior, structural pruning — not topping
This is why one-size-fits-all advice doesn’t work.
⚠️ Safety Overrides the Calendar
Some work happens year-round, regardless of season:
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Storm damage
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Hazard mitigation
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Dead or failing limbs
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Risk to structures or people
Safety always comes first.
🌿 Our Approach
We don’t prune based on convenience or calendar alone.
We prune based on:
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tree biology
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local climate
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long-term health
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site-specific conditions
If a requested timing or approach risks long-term damage, we’ll recommend a better alternative — or wait.