Boonville’s Incense Cedar Grove Mystery

If you enjoy identifying native plants, and recognize a plant growing where it shouldn’t be, it leads you to wonder “How did that tree get there?”

Take the Incense Cedars growing in the Rancheria Creek drainage along Highway 128 south of Boonville.

Incense Cedars are native to the western slope of the Sierra between 3,000’ and 6,000’. How and why are they growing along Highway 128? And the ones growing on 128 looks wimpy, nothing like the 150’ tall Sierra cedars. Growth ring counts studied in the 1970’s on the ones along 128 show them to be over 100 years old.

Where did they come from?

As a historian, I’d like to think a pioneer gold miner from the Sierra carried cones in his pocket and like Johnny Appleseed spread the seed around.

Or did a settler sprout, nurture and plant a sprout next to a homestead because they liked the aromatic foliage?

The answer might be the dirt under the roots. It’s a random act of nature.

Incense Cedars like rocky greenish Serpentine soils and there is a small, outcropping of this soil on 128. This soil is high in magnesium and low in calcium and is toxic to a lot of vegetation.

This writer supposed, at first, that these were the only Incense Cedars in the county but they have been documented in several locations in botanical surveys. They are in the Snow Mountain Wilderness, Mt. Sanhedrin, the North Coast Range Preserve, and northeast of Laytonville near Red Mountain. 

So they were not a mystery, misplaced from their natural range in the Sierra. Rather they are a species taking advantage of their favorite dirt wherever it appears Mother Nature teaches us something new every day.