1. Native / Non-native Status
Native to the UK and much of Europe.
2. Evergreen / Deciduous
Deciduous – leaves fall in autumn.
3. Appearance
Leaves: Rounded, almost circular (5–10 cm), with a slightly notched tip and shallow, irregular teeth along the edges. Glossy dark green in summer, paler underneath. Arranged alternately.
Bark: Dark grey to blackish, fissured with age. Often covered in lichens or moss in damp places.
Flowers/Fruit/Seeds: Distinctive. Male catkins are long, reddish, and pendulous, appearing in late winter. Female flowers form small, green cones that ripen to woody brown cones (strobiles), which persist on the tree through winter.
Overall shape: A medium-sized tree with a narrow to conical crown when young, becoming broader and more irregular with age.
4. Typical Size
Usually 15–25 m tall; spread 6–10 m.
5. Habitat & Range
Widespread across the UK. Strongly associated with wet places – riverbanks, lakesides, marshy ground, and floodplains. Thrives in waterlogged soils where many other trees fail.
6. Distinctive Features (ID tips)
Rounded leaves with notched tips.
Persistent woody cones on bare twigs in winter.
Preference for wet soils and riversides.
7. Seasonal Changes
Spring: Male catkins elongate and shed pollen; female catkins begin developing.
Summer: Glossy green leaves, female cones enlarging.
Autumn: Leaves turn dull yellow-green before falling; cones ripen brown.
Winter: Woody cones remain on bare branches, useful for ID.
8. Human Uses
Timber resists decay underwater, historically used for foundations, river pilings, and water pipes (e.g. Venice was built on alder piles).
Coppiced wood used for charcoal, clogs, and turnery.
Bark used in tanning and dyeing.
9. Wildlife Value
Catkins provide an early source of pollen for bees.
Seeds eaten by siskins, redpolls, and goldfinches.
Supports nitrogen-fixing bacteria in its roots, enriching soils and benefiting surrounding plants.
Provides valuable riverside habitat for invertebrates, fish, and amphibians.
10. Fun Fact / Cultural Note
In folklore, alder was seen as a magical, protective tree.
Its freshly cut wood turns from white to orange-red, which led to associations with bleeding or sacrifice in ancient stories.
11. Planting & Care (Basic Instructions)
Best time to plant: Late autumn or early spring.
Soil: Thrives in wet, poorly drained, or even waterlogged soils; tolerates neutral to acidic conditions but dislikes very alkaline chalk.
Light: Prefers full sun but tolerates partial shade.
Watering: Little needed once established, as it prefers damp sites. Water well if planted in drier soils.
Spacing: Allow 6–10 m between trees.
Aftercare: Mulch to conserve moisture. Young trees may need protection from browsing. Can be coppiced or pollarded if managed.
12. Good for Urban or Garden Setting?
Urban: Rarely used in city streets as it dislikes compacted, dry soils. Better for wetland parks or sustainable drainage schemes (SuDS).
Garden: Excellent in large gardens or natural ponds/wet areas; not suitable for small or dry gardens.
Bees: Bee friendly
Screen: Very good as a screen