White poplar

Populus alba

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Common look-alikes:

Identification

Appearance

Populus alba is a tree that can grow 40-80 feet tall and 40-50 feet wide. The bark on young trees is smooth and greenish white becoming gray and wrinkled, as trees age.

Foliage

The leaves resemble maple leaves, but the topside of leaves are shiny, dark green while the underside is bright white and hairy. Leaves are 2-4 inches long.

Flowers

Flowers are inconspicuous and develop in slim, cylindrical flower clusters (catkins) before the leaves develop.

Fruit

Fruit are small, hairy seed pods that are spread by wind.

Biology

This is considered a watch list species

Origin

Native to Europe

Habitat

Agricultural Field, Early Successional Forest, Edge, Floodplain Forest, Open Disturbed Area, Pasture, Roadside, Shrub Wetland, Vacant Lot, Wet Meadow, Yard or Garden. Populus alba prefers areas of disturbance where it can get ample sun. It can tolerate a variety of soils and different levels of pH, as well as a fair amount of salt.

Life cycle

Root suckers arise from adventitious buds on the extensive lateral root system. Large numbers of suckers from a single tree can quickly develop into a dense colony. Suckering can occur naturally or as a result of damage or other disturbance to the parent plant. Mature white poplar trees produce thousands of wind-dispersed seeds that may be carried long distances. However, seed germination of white poplar appears to be very low in the U.S.

Ecological Threat

Populus alba can form large clonal communities that are capable of excluding native species from edge habitats. When attempts are made to cut it back, it vigorously resprouts and spreads even more. Since it is competitive in early successional situations, it can interfere with succession in disturbed habitats. It is a very brittle tree that is easily broken and can cause damage to nearby structures or other trees.

Management Options

Mechanical Control

White poplar can be controlled using a variety of physical and chemical controls. Removal of seedlings and young plants by hand will help prevent further spread or establishment. Plants should be pulled as soon as they are large enough to grasp. The entire root system, or as much of it as possible, should be removed to prevent resprout from fragments. Hand removal of plants is best achieved after a rain, when the soil is loose.

Trees of any size may be felled by cutting at ground level with power or manual saws. Because resprouts are common after cutting, this process may need to be repeated many times until the reserves of the tree are exhausted. Girdling, which kills the tree by severing tissues that conduct water and sugars, also may be effective for large trees, especially if accompanied by application of a systemic herbicide to the cut area. A hatchet or saw is used to make a cut through the bark encircling the base of the tree, approximately six inches above the ground and deep into the bark. Girdling will kill the parent tree but may require follow-up cutting or treatment of sprouts with an herbicide.

Chemical Control

Be careful not to damage or kill nearby native plants when conducting management work.
Always read and follow pesticide label directions. Application of pesticides may require a certification from the Agency of Agriculture, Food and Markets. The Agency website provides information on what applicator certification is needed.

Chemical control of white poplar seedlings and small trees has been achieved by applying a 2% solution of glyphosate (e.g., Roundup®) or triclopyr (e.g., Garlon® 3) and water plus a 0.5% non-ionic surfactant to the foliage until the leaves are thoroughly wet. Use of low pressure and a coarse spray with large droplet size will reduce spray drift and damage to non-target plants.