Excavtion of knobcone pine roots in the Santa Ana Mountains showed that vertical roots grew to bedrock in the shallow soil. Trees produce female cones in groups of four or five, all firmly attached to stout branches in a tight whorl. The asymmetrical cones are arched in configuration, as are the individual ovuliferous scales. The lifespan of knobcone pine is relatively short. Unlike other closed-cone species whose cones open with hot weather, upon falling, or with age, unburned knobcone pine cones remain closed even after trees have decayed and fallen.
Cone scales open gradually following heating.
The first seeds fall within 1 to 12 hours after fire, when the ground has cooled. The arched scales continue to slowly expand and drop seed for at least 4 postfire years. The small, light seeds are wind dispersed. Santa Ana foehn winds, which blow during periods of low relative humidity, spread seed for great distances. Seed wings from charred or scorched cones often have fire-seared tips, causing seeds to fall in a slower spin than seeds with unburned wing tips.