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All ratings refer to the UK growing conditions unless otherwise stated. Minimum
temperature ranges (in degrees C) are shown in brackets
AGM plants have been through a rigorous trial and assessment programme. They are:
This plant will provide nectar and pollen for bees and the many other types of pollinating insects.
It is included in an evolving list of plants carefully researched and chosen by RHS experts. Divided into 3 groups these lists, linked below, are maintained by a team of RHS staff and are reviewed annually.
'Aurea' is a large, conical, deciduous tree with yellow-green leaves. Conspicuous male catkins, to 10cm long, appear in spring. The smaller female catkins are followed by small, cone-like fruit that turn dark brown in autumn and persist into winter
A. rubra is a medium-sized tree, to around 19m, fast-growing with a graceful habit, producing a narrow pyramidal head with rather pendulous branches. Leaves large, lobed, dark green above, greyish beneath. Long male catkins to 15cm. Fruits barrel-shaped, to 1.5cm long
A. glutinosa is a deciduous tree to 25m, broadly conical in habit when young, with grey-purple buds and young catkins conspicuous in winter, and rounded bright green leaves
A. cordata is a vigorous deciduous medium-sized tree with shiny deep green leaves. Male catkins yellow, to 10cm in length. Fruit 2.5cm in length, cone-like
A. incana is a conical tree, to 20m, with dark-green leaves to 10cm long, grey-white and hairy beneath. Yellow-brown male catkins in pendent clusters of 3 or 4 are produced in late winter or early spring, before the leaves. Ovoid fruit is produced in summer
'Imperialis' is a slow-growing medium-sized tree of conical outline and elegant habit, the leaves deeply pinnately lobed. Male catkins purplish, fruits small, cone-like
F. alnus is a bushy deciduous shrub with glossy rounded to ovate leaves which turn yellow or red in autumn, and clusters of small flowers in late spring and early summer, followed by bright red berries which ripen to black
Last-listed in the RHS Plant Finder in 2005
This plant is listed in the RHS Plant Finder book. At present our information about this plant is limited to a list of the nurseries that supply it. In time we will be adding more details including a description, growing information, advice and photographs.
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