Red Alder Trees

Alnus rubra

Red Alder trees, Alnus rubra, will grow vigorously in very wet soil, but they do need full sun. It is a slender, elegant tree with a neat, cone shaped canopy unlike some other Alders, it doesn't tend to produce suckers. Alnus rubra is quite decorative in spring, when the bare branches are festooned with long red catkins. Red alder gets its name from these catkins and from its wood, which flushes red when a fresh piece is split and exposed to the air. The green leaves are crinkled and serrated, turning mid-yellow in autumn. It can reach a height of 30 metres in ideal conditions, but 20 metres is more normal. The tallest Red Alder on record was 32 metres tall.  You buy younger Red Alder saplings here.

Browse our variety of alder trees or see our full range of garden trees for sale.

How Standard Trees are Measured:

All our standards, are graded by their girth in centimetres 1 metre above ground level (basically, their trunk's waist measurement). They aren't measured by their height, which will vary. So, a 6/8 standard has a trunk with a circumference of 6-8 centimetres and an 8/10 standard has a trunk 8-10 centimetres around. This measurement makes no difference to the tree's final height. Standard trees are 2.5 - 4.5 metres tall (on average) when they arrive; they are the most mature trees that you can buy from us.

History & uses of Alnus rubra: 

Red Alder is native to the West coast of America, where it is also known as Oregon Alder. It was introduced to Britain in the late 1800's. Like the rest of the Alder family, Red Alder has symbiotic bacteria living in nodules on its roots that improve the soil by releasing water-soluble nitrogen based compounds. Alders are especially useful for quickly binding loose, rocky soil. Red Alder is the traditional wood for smoking salmon in America.