Common / Black Alder Trees

Alnus glutinosa: Common / Black Alder. Standard Size Trees

Alnus glutinosa is a native tree that loves growing in wet, boggy soil. Young plants are slender and have a narrow canopy; mature old trees can spread quite a bit.
It has mid-green leaves that last until the end of autumn before they turn yellow. The yellow spring catkins develop into seed-bearing cones in the autumn, which are food for small birds. The catkins are wind-pollinated, and provide a source of protein-rich pollen for bees early in the year, when there isn't much else available, however, it's also a famous trigger for hay fever.

Common Alder trees can reach a mature height of about 20-25 metres in under 40 years.

These standard trees are the largest size that we deliver; you can also buy Common Alder saplings.
Browse our other alder trees or all our garden trees.

Features

• Thrives in wet and poor soils
• Very vigorous
• Great for bees & wildlife
• Old trees form dense thickets around them
• Can be coppiced & pollarded
• Fixes nitrogen
• Good for preventing soil erosion, especially on riverbanks
• To 25m

Growing Common Alder

It needs a sunny location on pretty much any soil, but if the site is really dry and drought prone, Italian Alder is a better choice. It won't grow on a beach, but it'll be fine quite close to the coast within reach of some salty winds. It does like chalk, but it doesn't like any rocky location (chalk or otherwise) with shallow topsoil.

Note on Alder roots: Alder has invasive roots that can break old water pipes and damage the foundations of old buildings or walls. 15 metres away from vulnerable structures is a safe distance to plant Alder. New build, concrete foundations aren't at risk.

History & Trivia

It is a classic pioneer tree that is often used to prevent riverbank erosion and to reclaim sites with especially poor soils, due to the bacteria living in nodules in its roots, which fix nitrogen from the air into the soil, improving it for other plants over time, especially as the tree ages and dies, or is pruned.

A concoction of the inner bark, simmered overnight in vinegar, was used to make an insecticide to kill lice and scabies mites, and was also used as mouthwash.

The timber is rot resistant and was widely used for foundations, clogs, and guttering in the past: most of central Venice is built on piles and platforms of alder, along with elm, oak, and poplar. It is good for smoking foods, especially fish.

Standard trees are measured by their girth in centimetres 1 metre above ground level: their trunk's waist measurement. Unlike sapling trees and hedge plants, standards aren't measured by their height, which will vary quite a bit both between and within species.
So, a 6/8cm standard tree has a trunk with a circumference of 6-8cm and an 8/10 standard has a trunk 8-10cm around. This measurement makes no difference to the tree's final height.
On average, standard trees are 2-3.5 metres tall when they arrive, but we cannot tell you precisely how tall your trees will be before we deliver them.