Plant of the Week
Cottonwood
Latin: Populus deltoides
Like Will Rogers, I never met a tree I didn’t like. I even like cottonwood.
Most folks who write about trees dismiss cottonwood with little comment or
downright scorn as a weedy, fast-growing, weak-wooded tree that is always
dropping something.
All of these may be true, but hey, nobody’s perfect.
My attraction to cottonwood, Populus deltoides, is probably more
sentimental than logical, for it was the one tree in central Oklahoma you could
count on to get big. Cottonwoods belong to the willow family, but they still can
reach 100 feet tall with trunks as much as 8 feet through.
The thickly furrowed, ash-gray trunks may be straight and true with the first
branch 40 feet off of the ground. Just as often they will be multi-trunked and
twisted and look more like a caricature of an impressionist’s painting than a
real tree.
The leaves, shaped like the spade on a deck of playing cards, are thick and
glossy green and flash in the sunlight with the slightest breeze. As these
leaves flutter in the breeze, they give off a rustling - a whispering - that
sounds like the spirits of old with stories to tell if we could but understand.
In the fall, these leaves turn a golden yellow that is one of the autumnal
highlights of the plains states.
Flowers on cottonwoods are borne in drooping panicles high in the trees, and
the only time one sees them is when they litter the lawn after bloom time.
Shortly thereafter, female trees begin producing snowdrifts of downy seeds which
drive neat-freaks mad.
Cottonwoods were the original explorers of this continent. If you look at
their distribution, you find they migrated up the major water courses; the
Mississippi, the Arkansas, the Ohio, the Missouri, the Platt and the Rio Grande.
From these major waterways, they spread up all of the riverlets and streams and
prospered in the moist alluvial flood plains throughout the country.
In the eastern woodlands, where better timber species grew, wood cutters
developed a general disdain for the cottonwood because its wood was brittle,
prone to extreme warping as it dried and just not as useful as oak or pine.
But, as westward expansion forced people onto the Great Plains, the
cottonwood suddenly became more appreciated. The early French trappers, who
shipped countless thousands of beaver pelts down the Platt and Missouri Rivers,
used cottonwood trunks as dugout canoes.
As the wagon trains of the Oregon and Santa Fe trail headed west, cottonwood
groves served as beacons on the featureless plains to point out water sources.
Greenville Dodge, as he headed up the Platt River Valley in 1866 building the
Union Pacific Railroad, used cottonwood cross ties on the new roadbed. Needing
2,400 ties per mile, and having no other locally available source of wood, Dodge
selected cottonwood knowing full well that the ties would last only three years.
In the great railroad race, speed was all important.
Cottonwoods are best used in large landscapes where the tree can be kept at a
distance or in difficult sites where a more refined tree will fail. Even though
cottonwoods are incredibly fast growing, with trees routinely reaching 30 feet
in less than seven years, they are too large for most suburban landscape
settings.
Souixland is a selection released by the University of North Dakota and is
the only cultivar routinely offered in the nursery trade. It performs better in
the prairie states than in the humid southeast where the various canker and leaf
diseases are more serious.
By: Gerald Klingaman, retired
Extension Horticulturist
- Ornamentals
Extension News -
January 25, 2002
Back to Archives A - D
|
