30 Apr White Poplar
White Poplar (Populus alba)
This month we are focusing our attention on one of the UK’s naturalised species, namely the white poplar. This deciduous tree grows up to heights of around 20m and forms a broad, spreading crown, but it is the two-tone effect of its leaves that is its most distinctive feature. Muted green on their upper surface, the underside is coated in white hairs, and when the wind lifts them the whole tree flashes pale.
The tree has deep cultural roots stretching back to ancient times, with links to both Greek and Roman mythology. The nymph Leuce, abducted by Hades, was transformed into a white poplar upon her death, and when Hercules returned from the underworld he crowned himself with a wreath made from its leaves. The duality of colour mirrors Hercules’ journey between the shadowy underworld and the sunlit world of the living, further linking the tree with heroism and endurance.
The white poplar has historically been used in medicine, particularly its bark which has astringent, antiseptic and anti-inflammatory properties, for the treatment of a range of conditions including rheumatism, digestive problems and gout. Its timber is soft but close-grained and easy to carve, making it a popular choice for sculptors.
In more recent times it has gained popularity as a wind-break, and thanks to its extensive root system and tolerance of salt it is often planted to strengthen coastal sand dunes. It is also planted simply for its beauty – its shimmering canopy makes it a striking ornamental in parks and gardens.
Appearance and Identification
As mentioned above, the leaves of white poplar are dark green on the upper surface and white on the lower thanks to a coating of white hairs. The leaves have five lobes with irregular teeth along the edges, and distinctly flattened stems.
White poplar are dioecious; the male trees produce grey catkins with dark red stamens, and the female trees produce yellow-green catkins which mature in late spring to early summer. Pollinated by the wind, once fertilised these develop into fluffy, cotton-like seeds which fall in late summer. The tree can also propagate by means of root suckers, often forming extensive clonal colonies.
The bark is also distinctive – smooth and grey with diamond-shaped lenticels that become dark and fissured with age.
Propagation and Control
White poplar thrive in full sun, in open landscapes rather than in deep woodland. They prefer moist soils and are often found along rivers and floodplains. They are remarkably tolerant of salt, pollution and poor soils, making it a good choice for urban and coastal planting.
It is generally a robust tree, although it is susceptible to issues such as cankers, leaf rusts and poplar scab. Its fast growth can lead to brittle wood, making the branches prone to storm damage, but overall it is relatively resilient when grown in suitable conditions.
Source and Reference Materials
Information detailed in this post has been obtained from the author’s own knowledge and photographic library where possible. Additional source of information and photographs include:
Van den Berk, B.V. (2004). Van den Berk on Trees. Van den Berk Nurseries