Pacific Poison Oak
Also known as: Toxicodendron diversilobum · Western Poison Oak
Causes skin burns — handle with care
When & where
Germination
Spacing & depth
How to plant
Stratify seed as noted. Sow in deep tree pots (tall root trainers) filled with well-drained mix. Keep evenly moist and in bright light after germination. Grow on for 1–2 seasons before planting out to a permanent, well-prepared site with a wide mulch ring.
Pre-sow treatment
60–90 days cold stratification; handle with care.
Grower's tip
Pacific Poison Oak (Toxicodendron diversilobum) — native western shrub/vine; causes severe skin irritation.
Woody plant facts
Good to know before you grow this
Parts of this plant are toxic to people and pets — don't eat it and keep it away from children and animals.
Soil preferences
Free-draining garden soil. Most shrubs fail from wet feet, not poor fertility.
5.5–7.0 for most; acid-lovers (rhododendron, blueberry) want 4.5–5.5.
Mulch a wide ring with compost or bark each spring; keep mulch off the stems.
Watering
Deep soak weekly for the first two seasons, then only in drought.
Slow soak over the root zone, not the crown.
Overwatered: yellowing leaves, dieback, sour soil. Underwatered: leaf scorch, early leaf drop, sparse bloom.
Prefers top-watering — Trees are always top-watered — deep slow soak at the drip line, never at the trunk. Bottom-watering only makes sense for nursery seedlings.
Temperature tolerance
Broad — hardy shrubs handle 35–90°F once established
Down to the species' rated zone minimum
Hardy once established; first-winter seedlings need a mulch collar or cold frame.
Special germination requirements
Most temperate tree seed needs cold stratification (30–120+ days at 34–41°F) — see each species entry for the exact time.
Container growing
Possible with the right cultivar
10–20 gal (38–76 L) for a long-term potted shrub
Dwarf and compact forms do fine in large pots; full-size shrubs eventually need the ground.
Detailed harvesting
Nothing here is harvested for the kitchen. Wear gloves, long sleeves and eye protection for any cutting, and wash tools, clothes and skin afterwards.
Post-harvest storage & preservation
Not applicable — this is a permanent planting.
Culinary, medicinal & other uses
Ornamental only — the sap burns skin. Handle in gloves and long sleeves, and never bring cuttings indoors or into the kitchen.
Medicinal or traditional uses are shared for interest only — this is not medical advice. Consult a qualified professional before using any plant medicinally.
Seed saving
Mostly insect-pollinated; seedlings vary from the parent.
Not practical. Named cultivars must be grown from cuttings, not seed.
Collect ripe seed or clean berries in fall, then cold-stratify before spring sowing.
Your zone's planting calendar
Pick your USDA hardiness zone and we'll estimate the key dates for pacific poison oak in your area. These are regional averages — always check your own last-frost forecast before sowing.
My Pacific Poison Oak notes
Pacific Poison Oak seeds on hand
Track packets and loose seeds you already have. Private to your account.
Par level — leave at 0 for no alert. Anything below par shows on Seed Starting and your shopping list.
Order more seeds
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