Alder, Italian (Alnus cordata)

Italian Alder (Alnus cordata)

Italian Alder is a pretty, fast growing egg shaped tree, often used as  windbreak.  it is extremely shapely, and at a distance, bears more resemblance to a pear tree than to the other members of the alder family. Italian Alder leaves, which are carried late into the year (and which are good in salads when young) are a shiny green and borne in much greater numbers than on other Alders. Like all Alders, Alnus cordata carries male and female catkins (both on the same tree) in March, which are pollinated by the wind. The fruit, which looks a bit like a small cone is carried in autumn and is feasted on by seed-eating migrant birds. Italian Alder bark is a brownish grey.

Alnus cordata is a nitrogen fixer and is therefore beneficial in poor soils which it improves over time - it is often used to reclaim land prior to planting with other trees. The wood of the Italian Alder is unremarkable except for the fact that it is to all intents and purposes rot-proof when submerged. It is often used as piling in bogs, rivers and lakes, and poles of Italian Alder formed the foundations of Venice.

Any soil will do, although Alnus cordata prefers heavier loams and wet clay. Italian Alder is happy in both acid and alkaline ground and will tolerate light shade. As if all that was not enough, Italian Alder grows well by the sea and makes a superb large hedge of 2 metres or so for which it should be planted at 2 per metre (50cm centres).  If grown as hedging, Alnus cordata is best clipped in late June or July.  In perfect conditions Italian Alder can reach 30 metres but it is more usually grows to 20-25m.