Aspen - Populus tremula

Irish name - Crann creathach
Ulster Scots name - Esp
Willow family - Salicaceae

Characteristics

• Aspen grow to a height of 20m (60ft) on reasonably fertile soil and occasionally more when planted. It can grow at higher altitudes, though it rarely reaches a height of more than 10m (30ft) in such areas.
• The light-grey smooth bark becomes darker and more rugged with age.
• The rounded leaves are borne on long flattened stalks which catch even the slightest breeze, causing the familiar trembling movement.
• Shallow-rooted, the root-branches run almost horizontal.
• Aspen reproduce by seed and also by suckers, often resulting in the growth of a small wood around a single tree. This ensures trees of the same strain and sex as the parent tree.

Season

• Catkins appear and flowers open between March and April, well before the leaves, which expand in May.
• Fruits are ripe in early summer, while the leaves, which show rich autumn colour, fall in October.

Preferred Environment

• Aspen is commonly found in groups on a moist, light soil. It is usually found growing in open woodlands on poor soils, particularly where they are permanently moist, but also occurs on scrubby heath-land where it may remain a bush.
• It is not normally found on soils with a high lime content, preferring neutral to acid conditions.
• Aspen does not thrive in woodland with a dense canopy as it is very intolerant of shade.
• It grows rapidly but is not long-lived, although it produces abundant sucker shoots.
• It is very tolerant of exposure and will do well in cold, windy sites as long as some moisture is present.

Wildlife Associations

• There are 97 identified insect species that are associated with aspen.
• It provides food for butterflies, moths, and gall-midges.
• After fifty or sixty years, the heart-wood begins to decay, and the tree’s destruction is then hastened by internal-feeding insects.
• A number of fungi are found specifically under aspen.
• Deer eagerly browse the suckers when they are accessible.

Uses

• Aspen wood is very light and has been used for veneer and plywood, for matches and light boxes for fruit and vegetables.

Please remember...

Permission from the landowner - and, if the site holds any kind of designation, from Northern Ireland Environment Agency too - must be sought before collecting plant material (including seeds).