The Black Alder Tree
It is a fast-growing tree (3 feet per year) and grows to a height of up to 100 ft. It has short-stalked rounded leaves and separate male and female flower in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water.
The common alder provides food and shelter to wildlife.
The bark of young trees is smooth, glossy and greenish-brown while in older trees it is dark grey and fissured.
The leaves of the common alder are short-stalked, rounded, up to 4 inches long with a slightly wedge-shaped base and a wavy, serrated margin. They have a glossy dark green upper surface and paler green underside with rusty-brown hairs in the angles of the veins. As with some other trees growing near water, the common alder keeps its leaves longer than do trees in drier situations, and the leaves remain green late into the autumn.
The seeds are flattened reddish-brown nuts edged with webbing filled with pockets of air. This enables them to float for about a month which allows the seed to disperse widely.
It tolerates a range of soil types and grows best at a pH of between 5.5 and 7.2. Because of its association with the nitrogen-fixing bacterium Frankia alni, it can grow in nutrient-poor soils where few other trees thrive.[15]
The common alder is important to wildlife all year round and the seeds are a useful winter food for birds. Deer, sheep, hares and rabbits feed on the tree and it provides shelter for livestock in winter.[15] It shades the water of rivers and streams, moderating the water temperature, and this benefits fish which also find safety among its exposed roots in times of flood. The common alder is the foodplant of the larvae of a number of different butterflies and moths[20] and is associated with over 140 species of plant-eating insect.[19]
These trees can live for up to 160 years!
Timber
The wood is soft, white when first cut, turning to pale red; the knots are attractively mottled. The timber is not used where strength is required in the construction industry, but is used for paper-making, the manufacture of fibreboard and the production of energy.[8] Under water the wood is very durable and is used for deep foundations of buildings. The piles beneath the Rialto in Venice, and the foundations of several medieval cathedrals are made of alder. The Roman architect Vitruvius mentioned that the timber was used in the construction of the causeways across the Ravenna marshes.[25] The wood is used in joinery, both as solid timber and as veneer, where its grain and colour are appreciated, and it takes dye well. As the wood is soft, flexible and somewhat light, it can be easily worked as well as split. It is valued in turnery and carving, in making furniture, window frames, clogs, toys, blocks, pencils and bowls.- - - - - - - - - - - - -
Zone 3-7
Mature Height: 40-100 feet
Mature width: 20-40 feet
Growth per Year: 3+ feet
Sunlight: Full-sun to partial shade
Soil Conditions: Prefers moist soil
Botanical Name: Alnus Glutinosa
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