By Rebecca Ohlin
Dive into the fascinating world of cottonwood trees and their indispensable role in supporting bee populations. Often referred to as “bee glue,” cottonwood resin is a vital resource for bees, boasting powerful antimicrobial properties that help maintain hive health. Moreover, cottonwoods produce natural rooting hormones, offering a practical advantage for gardeners seeking to propagate plants. Native to the United States, cottonwoods are easy to grow and provide essential habitats for various wildlife, from birds of prey to migratory songbirds. Despite their significance, cottonwood forests face numerous threats, including drought and urbanization, jeopardizing the ecosystems upon which bees rely. Ohlin urges readers to recognize the critical interdependence between cottonwoods and bee conservation, emphasizing the importance of preserving these vital trees for the sake of our buzzing friends.
Cottonwood Tree Facts
- Cottonwood tree resin is sometimes called “bee glue” because bees gather it to make propolis. The resin from the spring leaf bud is a powerful anti-microbial, sealant inhibiting fungal and bacterial growth.
- Cottonwoods produce natural rooting hormones. There is a practical application of this property of interest to gardeners. If you cut a small branch of cottonwood and place it in a vase with other plants you would like to root, it will augment the rooting process. Free rooting hormone!
- Cottonwoods need a location with full sun and lots of moisture. They grow particularly well along lakes and rivers as well as in marshy areas. The trees prefer sandy or silty soil, but will tolerate most anything but heavy clay. Trees may grow as much as 13’ in their first year and as much as 5’ in subsequent years under favorable conditions.They are hardy in USDA plant hardiness zones 2 through 9.
Cottonwood trees are native to the States, easy to grow, and have incredibly helpful properties that would make any beekeeper’s job easier. The resin is perfect for everything a beehive needs to be healthy.
Other fun facts about Cottonwood Trees
- Cottonwood bark, twigs, young branches and saplings make better feed for horses than hay.
- Beavers use cottonwood for food and building material. Deer eat leaves and twigs. Porcupines feed on the cottonwood catkins. Ducks and other waterfowl eat the seeds in the spring
- The trees grow large enough to provide habitats for eagles, hawks, and other birds of prey to build nests along with smaller birds and woodpeckers.
- Migratory songbirds, including warblers and vireos, nest and feed in cottonwoods each year. Over 50% of 166 species breed in riparian areas of the Southwest and cottonwood stands contain the highest bird densities of riparian areas in western North America.
- Native butterflies, including the larvae of western tiger swallowtail, Lorquin’s admiral, Persius duskywing and many kinds of moths, feed on cottonwood.
- Native to the United States, cottonwood trees may live from 80 to 300 years and reach a height of around 100 feet. Black cottonwood grows from Southern Alaska to Northern California mainly west of the Rocky Mountains. Other species of cottonwood including Balsam poplar (P. balsamifera), plains cottonwood (P. deltoids var. occidentalis), narrowleaf cottonwood (P. angustifolia) and Rio Grande Cottonwood can be found throughout the U.S. and Canada, and can be used interchangeably.
- Pacific Northwest tribes and early Euroamerican settlers collected and used the bud scale resin. Infused into oil, the resin was used to waterproof boxes and baskets. Hides and other natural fabrics were made waterproof by smoking them with cottonwood. Native Americans traditionally ate the sweet cambium and inner bark of cottonwoods in the late spring.
Many cottonwoods located in riparian areas are mature and/or in decline. Due to changing factors in these ecosystems, including drought, poor water management, and extensive overgrazing by livestock, cottonwoods are not surviving in some areas where they historically thrived. The forest component of the Missouri River is largely gone today, and that which remains is mostly old and dying. The majority of what was the cottonwood forest of the Missouri River in North Dakota is inundated by water held by Garrison and Oahe dams. The Southwest’s riparian forests are now among the most threatened woodlands of North America.
Dams have eliminated natural river flooding, shifting and meandering of channels and have significantly reduced creation of sandbar habitat—all processes needed to establish young cottonwoods. Other factors contributing to the loss of our cottonwood forests include urban sprawl and community development, farming practices, browsing livestock and deer, and undesirable and very competitive species like Russian olive and bromegrass. The interrelationships found in the cottonwood forests are complex, and the effects of changing or eliminating these interrelationships may be far reaching. More than 100 plant species are associated with cottonwoods through the succession from seedlings to maturity.
All that to say, to save the bees, we need to save the cottonwoods too. Please help spread the word?