Populus tremula - Aspen

Aspen is medium-sized, fast-growing native deciduous tree, with a wide distribution over Europe, Asia and Africa. A very distinctive tree, with leaves that shimmer and tremble in the slightest breeze, so that they are constantly moving and rustling. The leaves turn a rich golden yellow in autumn, and the young leaves are bronze in spring, making it attractive at all seasons. It is one of our most important trees for wildlife, supporting a wide range of insects, including the endangered Aspen Hoverfly. It suckers in the wild.

Site and soil

Aspen will grow well on all soils except very thin chalk, and thrives on exposed hillsides. It is very tolerant of long severe winters and short, cool summers.

Height and spread

Below are the approximate stages of growth, assuming sited in suitable conditions for this species;

After 10 years: 8m x 4m
After 20 years: 12m x 6m

Leaf and bark

The rounded leaves have flattened stalks which cause them to flutter and tremble in the slightest breeze. They turn a luminous golden yellow before leaf fall, making it one of the best trees for autumn colour; the emerging young leaves are bronze. The bark is grey, or greenish-grey, sometimes pitted with diamond-shaped lenticels.

Flower, seed and fruit

Female catkins are green, whilst males are red and green, both around 12cm long and produced in February before the leaves open. Aspen is dioecious, the male and female flowers being on separate trees. The catkins shed woolly seed in May which is distributed by the wind.

Uses

A beautiful specimen tree with year-round interest in parks, gardens and woodland. An excellent wildlife plant. The highly absorbent wood is used for matches and for animal bedding.

Wildlife

Aspen is an important tree for wildlife, supporting a large number of insect and butterfly species on both the living tree and rotting wood. It is a pioneer species in re-establishing woodland, and its ability to cope with harsh conditions makes it very valuable environmentally. Deer feed on the leaves.