Common Name: White Poplar
Scientific name: Populus alba
Identification: White poplar is a large deciduous tree, generally 40-70’ tall at maturity. While the species typically has a broad canopy equal to its height, some cultivated varieties are much narrower resembling a column or pyramid. Young bark is light greenish gray to white becoming darker gray and furrowed with age. Mature bark often has distinct, dark diamond-shaped blotches. The leaves alternate and are 2- 5” in length. The leaves are variable in shape. Larger leaves often have three to five lobes. Smaller leaves tend to be elliptical or oblong. All leaves have wavy margins and are dark green on the upper surface and white with dense hairs on the lower surface. The species is dioecious, meaning male and female flowers occur on different trees. Male flowers are 2-3” long red-to-purple catkins, while female flowers are 2-4” long green catkins. Females are more common than males in North America (Gucker 2010). Fruits are pods that break open and release cottony seeds in mid-spring. The root system of white poplar is large and shallow. Clonal growth from the root system is the primary mode of spread for this species outside of its native range (Gucker 2010). Clones originating from root sprouts often survive long after the original primary stem has died. (Dirr 1998, Dirr and Warren 2019)
Look-alikes: White poplar can be differentiated from native poplars such as eastern cottonwood (P. deltoides), big-tooth aspen (P. grandidentata) and quacking aspen (P. tremuloides) by its variable leaf shape, the distinct lobes on its larger leaves, and the dense, hairy white leaf undersides.
White poplar has been reported throughout the U.S. portion of the Great Lakes Basin. It is reported in all of the lower 48 states, though it is more common in the eastern half of the U.S. USDA reports white poplar as being hardy to a minimum temperature of -38oF (Zone 3). Invasive populations are most frequent in areas where the species was planted as a wind break or for other landscape purposes.
Additional invasive species distribution data for specific Great Lakes jurisdictions are available via:
- Midwest Invasive Species Information Network (Michigan)
- iMapInvasives (New York and Pennsylvania)
- EDDMapS Ontario
Although white poplar reproduces by seed in its native range, sexual reproduction is thought to be rare in the U.S. (Gucker 2010). However, white poplar is known to interbreed and hybridize with big-tooth aspen (P. grandidentata) and these hybrids reproduce by seed. Most reproduction causing invasive concern in this species is through clonal growth in areas near historic plantings.
White poplar requires full sun for rapid expansion and is most frequently found in recently disturbed sites, old fields, open forests, forest edges, riparian zones, disturbed prairies and grasslands.
White poplar can form large single-species colonies through clonal growth from the roots and can suppress the growth of native trees and shrubs, herbaceous plants and grasses by establishing dense shade and blocking access to soil nutrients and water.
Hybridization and introduction of white poplar genes into native poplar species is of potential concern. However, research conducted in the Midwest has shown little influence on native poplar genetics to date (Gucker 2010).
White poplar can cause property damage if allowed to grow too close to buildings or infrastructure. Colonies have very large, shallow root systems that can physically damage structures and impact the movement of stormwater (Dirr 1998).
White poplar has been a part of the American landscape for over 270 years, but is no longer commonly used. It was planted as a wind break or property line marker due to its very fast rate of growth and the attractiveness of its foliage. However, it is prone to storm damage, making it less-than-ideal on the landscape. It is also prone to a number of diseases and is rarely planted today.
Please see our Landscape Alternatives pages for more information about how the WIGL Collaborative selected alternatives.
|Alternatives for White Poplar
Common name (Latin name)
|Tulip poplar / tulip tree (Liriodendron tulipifera)||✔|
|American sycamore (Platanus occidentalis)
|Big-tooth aspen (Populus grandidentata)||✔a||✔||✔|
|Quaking aspen (Populus tremuloides)||✔a||✔||✔|
|London planetree (Platanus x. acerfolia)
‘Morton Circle’ EXCLAMATION!™
|Silver linden (Tilia tomentosa)||✔|
a Similar to white poplar, native poplars tend to sustain wind damage and also form clonal colonies. Therefore, they may not be suitable for urban or suburban settings.
Green = native to part of the Great Lakes Basin
Blue = not native but not invasive
The WIGL Collaborative’s decision trees are designed to help site users, who are perhaps newly discovering that plants that are part of their home landscaping are invasive, prioritize which species should be removed first based on risk to the surrounding environment, economy, and occasionally, to human health. In a perfect world, everybody would remove all invasive plants from their landscaping right away, but in reality, removing mature woody plants involve a hefty investment of time and/or money. These diagrams can help people with multiple woody invasives in their landscaping prioritize to get the most benefit for their efforts.
To learn more about the methodology and information used to develop the decision trees and for helpful hints on how to answer the questions, please see the full report here (PDF).
The following is a brief overview of management techniques shown to be effective on white poplar. For more detailed information on how to use these techniques, please visit our Management and Control page. For technical assistance on managing woody invasive species, please get in touch with a local cooperative invasive species management group.
Physical control: There is very little information available about control of white poplar. Potential techniques include physically removing individual plants and colonies by cutting/mowing or girdling. Cutting and mowing are only effective if root sprouts will be re-cut over many years, or if a prescribed fire program can be initiated following cutting. It is not known how many years of treatment with cutting or fire would be required for effective control (Gucker 2010). Conducting the initial cut at the peak of the growing season when resources are lowest may reduce regrowth. Mature trees and root suckers over 2” in diameter can be girdled in early summer by removing a four inch strip of bark and cambium from the whole circumference of the trunk. Girdled trees should be monitored for new shoots sprouting from the base or nearby root system and managed.
Chemical control and combined approaches: Foliar herbicide treatments are effective if applied when leaves have fully emerged and the plant is actively growing. Cut stump and basal bark herbicide treatment are also effective and can be applied during most of the year outside of spring sap flow. Herbicide should be selected carefully based on site conditions, and label directions read and followed carefully.
With any treatment it will be necessary to monitor for and treat regrowth in subsequent years. This is especially true for white poplar due to its large root system and tendency to sucker.
Resources on management of white poplar:
- Dirr, MA. 1998. Populus alba In: Manual of Woody Landscape Plants, Fifth Edition. Champlain, IL: Stipes Publishing. 762-763.
- Dirr, MA and KS Warren. 2019. Populus alba In: The Tree Book: Superior Selections for Landscapes, Streetscapes, and Gardens. Portland, OR: Timber Press. 644-645.
- Gucker, CL. 2010. Populus alba In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. 1/31/2019.
Photo Credit: Distinct two-tone foliage of white poplar is dark green above and hairy white below (Photo: Clair Ryan, Midwest Invasive Plant Network)