Alder Tree (Alnus glutinosa)
An Alder tree is a member of the Birch tree family. This deciduous tree grows quickly to a height of approximately 25 feet, and is fairly short lived at 150 years.
Often described as a ‘pioneer species’ Alder conditions the soil, putting nitrogen into it, so other species of tree can grow.
Alder grows well in wet areas, such as on the banks of a stream, pond or boggy woodland.
Identifying the Alder Tree
Leaves – the leaves of the Alder tree open in April, and grow on long stems. They grow to approximately 10cm. They are light green and rounded, although they do taper to a slight point near to the leaf stalk. The edges are wavy, and the leaves have distinct veins. The leaves fall off the tree in late autumn.
Bark – the older bark on an Alder tree is a grey colour and has fissures, while the young bark has a greenish or light brown hues and spots. The new stems are sticky.
Flowers – Alder trees are monoecious, producing both male and female flowers, or catkins, which come out from February to April. The male catkins are yellow, and the female are green and oval shaped. When the female flowers are fertilised, they develop into green, cone-like fruits that bear seeds.
Uses for Alder
Fire – Seasoned Alder wood burns fairly quickly and produces a good amount of heat and coals. For a longer lasting fire, mix it with other types of wood. Avoid putting Alder on the fire if it is not properly seasoned as it will give off a lot of smoke.
Food – Charcoal made from Alder is good quality can be used to give a mild, smoky flavour to barbeque food. The chippings can be used to smoke food to preserve or flavour it, and works well with most meats and also salmon, giving it a sweet, smoky flavour.
Coppicing – Alder coppices well, and almost anything can be made from the wood, but the real benefit of the timber is that it has the advantage of withstanding continual wet and dry conditions. When used underwater, it hardens and withstands decay. In the past Alder wood was often used to make water troughs, water mill wheels, and lock gates. It has also been used in the construction of bridges.
Crafts – Because of the moisture content, carving green Alder wood is a pleasure. The soft wood is easy to shape and yields well under a tool, so many items can be carved. Traditionally, wooden clogs were often made from Alder wood.
The leaves and bark can be used in dye making. The freshly cut wood is white, but gradually turns to a red colour. A green dye can be produced from the flowers.
Health – Alder tree bark contains salicin, which converts into salicylic acid, an anti-inflammatory, in the body.
A tincture made from the bark can be applied to the skin to soothe irritation from insect bites. Infusing the leaves, flowers and bark with a carrier oil, such as almond, creates a soothing balm that may help with some skin disorders, as will a poultice made from the leaves.
Placing the leaves inside shoes is said to soothe aching feet and prevent swelling.
Ingesting fresh Alder tree bark in any form will cause vomiting, so to use it for any reason other than externally, the bark needs to be dried first.
A mouthwash made from Alder bark has been used to treat sore throats, inflamed gums, tooth ache and mouth ulcers.
Wildlife – Alder provides many benefits to wildlife. The pollen from the catkin is an early source of pollen for bees, and if the branches are above a stream or river, the seeds are a food source for fish. Alder is a good species for reforestation, and provide excellent shelter for wildlife in wet areas.
The roots of Alder trees add nitrogen to the soil, and improves its condition and makes it more fertile. Plant Alder to establish tree growth in water-logged or boggy areas, or to help prevent soil erosion.