Six poplar trees and how to identify them

Poplar trees are diocious, meaning the male and female catkins are borne on separate trees. Catkins vary in colour depending on whether the tree is male or female – those on male trees tend to be more colourful, while those on female trees mature to produce an abundance of fluffy white seeds. The downside of poplars is their extensive and fast-growing root system, making it highly inadvisable to plant anywhere near buildings. What's more, seeds from female trees disperse widely and can cause a mess, and the fragile stems have a tendency to break and shed around the tree.

In total there are around 35 poplar species, which are native all over the Northern Hemisphere from Europe to China, as well as North America where some poplar species are known as cottonwoods. Some poplar trees are native to the UK and populations of mature black poplar trees were once important trees in the landscape. Many types of poplar tree are special not just for their age and landscape value, but also for a variety of practical uses. Being tough, hardy, and with rapid growth, they are ideal for using as large windbreaks and screens. In the wild most poplars grow in valleys, rivers, and swamps and in moist ground. A handful of species, including Populus alba, grow in drier conditions and are also useful for coastal planting.

The wood of some poplar species once had a variety of uses but much less so nowadays. Confusingly, in the US the wood of an unrelated species, Liriodendron tulipifera, is known as poplar wood, though this term is not used in the UK.

Common types of poplar tree and how to identify them

Populus alba (white poplar)

This is a large tree with a broad, rounded head. Grey bark is patterned by black diamond-shaped fissures, known as lenticels. Vivid green leaves are silvery-white on the undersides and look spectacular when blowing in the wind, turning bright yellow in autumn before falling. Their shape is slightly lobed and almost maple-like. White poplar is widely naturalised in the UK though originally introduced from south-east Europe. A tough, hardy tree, it's particularly good for growing in exposed and coastal locations. Height x Spread: 12m x 8m

Populus x candicans ‘Aurora’

This species is ideal for gardens as it's best pollarded (pruned back to the trunk) to encourage plenty of young variegated foliage, which is a colourful blend of cream-white and green, tinged with pink. Older leaves are mid-green in colour. Un-pruned trees are broadly pyramidal in shape and grow to a height of around 20 metres. H x S: 8m x 4m

Populus x canescens (grey poplar)

Grey poplar is a hybrid between Populus alba (white poplar) and Populus tremula (aspen). Particularly vigorous in growth, it forms a substantial tree which is broadly columnar in shape, spreading with age. Glossy dark green leaves are woolly and grey beneath, similar in shape to those of white poplar. Long red catkins are borne on male trees and green ones on female trees, in spring. H x S: 20m x 10m

Populus nigra (black poplar)

Native to the UK as well as Europe, black poplar is a handsome and distinctive species that forms a large, rounded tree with substantial branches, the mature trunk attractively fissured and burred. Young growth is ochre yellow in colour and looks handsome during the winter months once the leaves have fallen. Reddish catkins are borne in spring. Black poplar was once widely grown across England and Wales in riverside and damp areas, this tree appears in a number of paintings by the artist Constable. Many black poplars would have been pollarded to harvest the wood for uses such as making sheep hurdles, cattle fodder, bean poles, and fruit baskets. There are still populations of mature trees, particularly in areas such as the Vale of Aylesbury, and work is under way to conserve and boost this important tree. H x S: 20m x 10m

Populus nigra ‘Italica’ (Lombardy poplar)

Tall growing yet very slender and columnar, this variety of poplar is widely planted along roadsides in Europe, particularly France, to create attractive screens and windbreaks. It was originally found growing in the region of Lombardy, hence the name. H x S: 15m x 8m

Populus tremula (aspen)

Not strictly a poplar but a close relative, aspen (or quaking aspen) gets its name from the way its small serrated green leaves tremble and rustle in the breeze. While trees are individually relatively short-lived, to around 50 years, aspen tends to spread by suckering to form a small colony. This species grows best in cooler areas. Native to the UK and also found as far afield as Asia, China and Japan as well as Europe. H x S: 15m x 8m