What does it take to earn a regional and national title? The Black Cottonwood of Willamette Mission State Park could tell you.

Black Cottonwood’s are native to Oregon and can be found from Alaska through northern California, and eastward into Montana. Cottonwoods are typically very tall and large trees and are the largest popular species in the Americas.

Image courtesy Oregon State University Extension

Typically, they will grow up to 164 feet and have a trunk diameter over 6.6 feet. Our winner, the “Willamette Mission Cottonwood,” measures 155 feet (47.26 m) tall, 29 feet around (8.8 m), with a crown that stretches just over 93 feet.

Cottonwoods live relatively short-lived trees. Some will reach 400 years old.

As they age, the bark hardens becoming thick and fissured. By age 20, cottonwood bark has thickened enough to help protect the tree from fire. At this point, the bark is hard enough to cause sparks when cut by a chainsaw.

Seedlings and saplings can be killed or damaged by fire. Repeated fire can completely eliminate all Black Cottonwood from an area.

This tree is a natural colonizer and after a burn may be able to colonize large areas with good light, moist soil, and bare mineral soil from seed.

What makes this an important tree?

The light-colored hardwood has a fine, even texture with indistinct growth rings and a fine grain. The wood is light weight and ideal for making a number of products (such as pallets, boxes, crates, furniture, high-grade paper, fuel pellets, and plywood). 

Cottonwoods are frequently used for windbreaks, shelterbelts, and road screening. The aggressive root system makes it an effective soil stabilizer and useful in riparian and aquatic restoration projects.

Research is continuing on species hybrids as potential sources of biomass. They grow faster than any other northern temperate region tree and are easily propagated.

They are fast to re-sprout, and quick to harvest. Some sites have so much existing seed, they don’t need to be seeded after harvest.

(This raises the question of ‘Could these hybrids become a future noxious and invasive weed?’)

Even the critters like it

Black cottonwood provides cover and food for deer, elk, beaver, and birds. Even rotten trunks are useful in areas with scarce shelter.  

Black Cottonwood male flowers (image courtesy Oregon State University Extension)


Many people are, unfortunately, negatively impacted by the copious amounts of tree pollen. Male trees release pollen in late May and June, about three weeks before the females release seed.

Trees create an abundance of seeds every year. Seed release resembles a serious snow storm.

Cotton-like hair is attached to each seed. This hair keeps seed afloat on air or water for long distances. The seed can sprout one day after touching the ground!

Seeds and cotton-like hair (image courtesy OSU Extension)

Native Americans discovered that the tree resin was good for treating sore throats, coughs, lung pain, and rheumatism, and that the inner bark good for creating soap.

And then…

Perhaps the most perplexing questions about this large tree is how one would go about measuring a giant one. I guess you just have to climb to the top, drop a very long tape measure, and hold on tight…  

–Heritage Trees, Oregon (https://oregontic.com/oregon-heritage-trees/willamette-mission-cottonwood/)
–Oregon State University, Landscape Plants, Populus trichocarpa (https://landscapeplants.oregonstate.edu/plants/populus-trichocarpa)
–USDA, Natural Resources Conservation Service, Plant Guide, Black cottonwood (Populus balsamifera L. ssp. trichocarpa (Torr. & Gray ex Hook.) Brayshaw (https://plants.usda.gov/core/profile?symbol=POBAT)
–King5 “Is cottonwood fluff causing your allergies? (https://www.king5.com/article/news/local/take-5/take-5-is-cottonwood-fluff-causing-your-allergies/281-557522159)
–Monumental Trees, Exactly Measuring Tree Height (https://www.monumentaltrees.com/en/content/measuringheight/)