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by J. Reimer, M. Ritter
GENERAL INFO
Knobcone pine occurs discontinuously on arid, rocky slopes and ridges in coastal ranges from San Bernardino County to southwestern Oregon and from the central Sierra Nevada northward through the Cascade and Klamath ranges. It is California's most fire-dependent conifer. Knobcone pine is a closed-cone pine. This species, along with Monterey and Bishop pines, has thick woody seed cones whose scales stay sealed with pitch, only releasing their seeds after the high temperatures of a fire. Most stands are even-aged, with individuals all having germinated after the fire that killed the previous generation; they often grow in dense thickets. Knobcone pine is a three-needle pine with wispy crowns of pale green foliage and slender trunks and branches covered with long-persistent, asymmetrical seed cones.
Native range: California and Oregon
Native range: California and Oregon
TREE CHARACTERISTICS
Tree Shape: RoundedFoliage Type: EvergreenMaximum Tree Height: 80 feetCanopy Width: 20-25 feetGrowth Rate: ~36 in/yearLeaf Arrangement and Leaf Form: Alternate, SimpleLeaf Shape: NeedleLeaf color: Bluish Green or Silver or Gray GreenReproduction: Has either male or female reproductive parts (dioecious)Cones: Very Large Brown ConePollen time: Fall or WinterBark Color: Dark Brown or Purple, FissuredLitter Type: Dry Fruit
SITE CONDITIONS
Recommended Planting Area: Greater than 7'Water Use Rating: LowSunset Climate Zone: 1 - 10, 14 - 21Shade Tolerance: NoUSDA Hardiness Zone: 7, 8Soil Texture: Loam or Sand or ClaySoil pH: Very Acidic to Slightly AlkalineSalt Tolerance: Moderate
CONSIDERATIONS
Branch Strength: Medium Weak to MediumRoot Damage Potential: ModeratePotential health issues: AllergyBiogenic Emissions: ModerateWildlife interactions: Attracts birds, squirrelsDisease and Pest susceptibility: Armillaria, Pitch Canker and Aphids, Beetle BorersDisease Resistance and Pest Resistance: VerticilliumUtility Friendly: No
External Resources
CITE THIS TREE
"SelecTree. UFEI. "Pinus attenuata Tree Record." 1995-2025. Cal
Poly State University, San Luis Obispo. Accessed on Jun 11, 2025."
< https://selectree.calpoly.edu/tree-detail/1030 >
< https://selectree.calpoly.edu/tree-detail/1030 >
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