paulownia-500x500So many trees beginning with ‘P’- which to choose? My choice is a tree that poses a dilemma- to prune or not to prune? If you do, you will encourage massive foliage which is a fabulously exotic addition to any garden. Alternatively, don’t and you get some wonderful flowers…the choice is yours.

Common name: Foxglove Tree, Empress Tree, Princess Tree

Native areas: Pawlonia tomentosa (syn. P. imperialis) is native to Japan and central and western China, where it has become virtually extinct due to a pathogen. It has become very common in North America, where it is considered an exotic invasive species. It was introduced to the UK in 1834.

Historical notes: The tree was named after Anna Pavlovna, daughter of Tsar Paul I and wife of Prince Willem of the Netherlands. In China, the tree is planted at the birth of a girl. The fast-growing tree matures when she does. When she is eligible for marriage the tree is cut down and carved into wooden articles for her dowry. Carving the wood of Paulownia is an art form in Japan and China. In legend, it is said that the phoenix will only land on the Empress Tree and only when a good ruler is in power. Several Asian string instruments are made from P. tomentosa.

The soft, lightweight seeds were commonly used as a packing material by Chinese porcelain exporters in the 19th century, before the development of polystyrene packaging. Packing cases would often leak or burst open in transit and scatter the seeds along rail tracks and near to ports. The magnitude of the numbers of seeds used for packaging, together with seeds deliberately planted for ornament, has allowed the species to be viewed as an invasive species in areas where the climate is suitable for its growth, notably Japan and the eastern United States.

Features: Paulownia tomentosa is an extremely fast-growing tree; its growth rings have been measured at three every inch. However the UK’s climate slows this down, and any growth under a pencil thickness generally succumbs to winter frosts, and which in turn contribute to its overall broadness. It will ultimately grow to 10–25 m (33–82 ft) tall, with large heart-shaped to five-lobed leaves 15–40 cm (6–16 in) across, arranged in opposite pairs on the stem. On young growth, the leaves may be in whorls of three and be much bigger than the leaves on more mature growth. The leaves can be mistaken for those of the Catalpa.

The very fragrant flowers are formed in autumn and then open in spring before the leaves in early spring (May), on panicles 10–30 cm long, with a tubular purple corolla 4–6 cm long resembling a foxglove flower. However, if there is a prolonged period where winter temperatures fall below minus 5 degrees celsius, no flowers will develop the following spring.The fruit is a dry egg-shaped capsule 3–4 cm long, containing numerous tiny seeds. The seeds are winged and disperse by wind and water. Pollarded trees do not produce flowers, as these only form on mature wood. A mature tree in its native environment can produce up to 20 million seeds a year!

Uses: P. tomentosa is cultivated as an ornamental tree in parks and gardens. It has gained the RHS Award of garden Merit (AGM). The characteristic large size of the young growth is exploited by gardeners: by pollarding the tree and ensuring there is vigorous new growth every year, massive leaves are produced (up to 60 cm across). These are popular in the modern style of gardening which uses large-foliaged and “architectural” plants. Alternatively it can be grown for its attractive, fragrant flowers.

Growing conditions: a fast growing, medium to large tree, it does best in a sunny, reasonably sheltered site, preferably in moist, humus-rich, fertile soils. Protect young trees from frost. Can be pollarded. Very tolerant of atmospheric pollution.

Paulowni_imperialis_SZ10Further information:


RHS- Pawlonia tomentosa

Barcham trees directory- Pawlonia tomentosa

Old School Gardener