Back in the 1970s, responding to the loss of 30 million elm trees in Britain due to diseas, the then Department of the Environment encouraged us to ‘Plant a Tree in ‘73’ (the slogan the following year was, inelegantly, ‘Plant one More in ‘74’). The majority of trees planted that year were sturdy British natives. With all the pretentiousness of adolescence I opted for a tree I had never seen but which had a great name and which was the only species in the genus: Parrotia persica. Choosing to plant a tree based solely on its name could have been disastrous but, fortunately for me (or, rather, for my parent’s garden), it turned out to be a good choice and I have since planted one in my own garden.
One of the joys of the tree is the autumn colouring of its attractive scallop-shaped leaves. These change their colour during several weeks in mid-autumn with every leaf appearing to be a different colour. Intense reds, glowing oranges and vivid yellows all on the tree at the same time make it the most flamboyant tree in the garden. The effect is dazzling, and a slight breeze sets the whole tree shimmering. The only other tree that is anywhere near as spectacular as this is the Liquidambar. Other trees produce colourful autumn foliage but none are as reliably impressive as Parrotia.
The name comes not from this gleaming autumn colouring, as some people imagine, but commemorates a 19thC German naturalist, improbably named Herr Parrot. William Stearn, a great source of gardening trivia, points out in his Dictionary of Plant Names that Herr Parrot is also credited with being the first person to climb Mt Ararat.
Parrotia persica will reach about 30ft but is very slow-growing. Initially a narrow, upright shape it will eventually branch out to make an elegant, domed tree. The trunk tends to be very short, with the branches growing up from the bottom. As the tree matures its trunk and main branches start to loose their bark. Similar to that of the London Plane, the bark flakes away to form a patchwork of steely grey and white. The tree’s common name of Ironwood tree perfectly describes its smooth metallic sheen, and it is impossible to resist rubbing your hands across its silky surface.
Great autumn colour and striking winter bark are just the ‘overture and beginners’ of the tree’s performance. At the start of the year, before there is any sign of new leaves, Parrotia persica flowers. More discreet than its autumn pyrotechnics, the clusters of tiny blood-red flowers are none-the-less welcome during the dark winter days.
How to grow
Parrotia persica prefers a rich, fertile soil that does not dry out. It will not tolerate drought and during last year’s hot dry summer I noticed several Parrotias beginning to lose their leaves in response to the stress the dryness caused. If you can, plant the tree in a sheltered spot away from cold, drying winds. This will also give some protection from the frosts that can turn the early flowers to mush. The tree is reputed to prefer slightly acid soils, but it will tolerate even chalky conditions. Two cultivars, Parrotia persica ‘Vanessa’ and Parrotia persica ‘Jodrell Bank’ (raised at the arboretum next to the radio telescope) grow well in either acid or alkaline soils. The only pruning that the tree needs is the cutting out of cross branches on mature trees and, if necessary, the removal of branches from the base of the tree to reveal the trunk.