A mature Italian Alder in the St Thomas pleasure grounds of Exeter, UK.
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It is a deciduous Tree growing to 25 m (82ft) by 8 m (26ft) at a fast rate.
It is hardy to zone (UK) 6.
It is in leaf 12-Apr It is in flower in March. The flowers are monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by Wind.
It can fix Nitrogen - which makes it a very useful plant for areas that have really bad soil quality.
Suitable for: medium (loamy) and heavy (clay) soils and can grow in heavy clay and nutritionally poor soils. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry moist or wet soil. The plant can tolerate maritime exposure.
Deciduous, dark green glossy, heart-shaped leaves, 4cm long. The bark is smooth and grey, with short vertical cracks.
Alder trees also have a heavy leaf canopy and when the leaves fall in the autumn they help to build up the humus content of the soil.
Alder seedlings do not compete well in shady woodland conditions and so this species gradually dies out as the other trees become established
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Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fagales
Family: Betulaceae
Genus: Alnus
Subgenus: Alnus
Species: A. cordata
Binomial name
Alnus cordata
