Alnus cordata

21 Feb

Alnus cordata Summer (28/07/2012, Kew Gardens, London)

Position: Full sun

Soil: Moist, well drained. Will tolerate wet conditions

Flowering period: Late winter to early spring

Eventual Height: 25m

Eventual Spread: 6m

Hardiness: 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b

Family: Betulaceae

Alnus cordata is deciduous with a conical habit and will retain its leaves until the first hard frost, sometimes well after Christmas. It has broadly ovate, dark green, glossy leaves which are heart shaped at the bases. The leaves are preceded by groups of 3 to 6 pendant, yellow to brown catkins which although edible have a very bitter taste. These are followed in summer by small ovoid fruit which are often retained on the tree for a number of years. Its roots form an association which enable them to fix nitrogen in the soil.

Alnus cordata Female Flower and Leaf (28/07/2012, Kew Gardens, London)

Alnus cordata, commonly know as Italian Alder, is native to Corsica, Italy. The catkins were supposedly the source of the dye used by Robin Hood and his band of merry men t0 make their cloaks green.

The etymological root of the binomial name for Alnus is the old Latin name for Alder trees. Cordata is derived from the Latin meaning heart shaped which describes the leave shape.

Alnus cordata catkin (19/02/2011, London)

Alnus cordata is useful to the landscape architect due to it being a pioneer plant, its ability to nutrify soils, and its ability to quickly forms a windbreak. This tree is also very useful when a tree tolerant of wet soil conditions is required. It will produce a fine shaped tree that will require little maintenance to retain its naturally pleasing architectural habit. This tree can also be coppiced.

Ecologically, Alnus cordata will attract certain native finches to eat its seed.

The Royal Horticultural Society have given Alnus cordata their prestigious Award of Garden Merit.

Alnus cordata prefers most moist soils. It will tolerate most soils pH. It will not grow on acidic peat or shallow, chalky soils.