The Princess Tree, or Paulownia tomentosa, is a deciduous tree that is native to central and western China. This tree is also known as the Empress Tree or Foxglove Tree and is invasive in the US. It can grow from 10-25 m tall with leaves that are either heart-shaped or five-lobed. Both leaf styles are typically 15-40 cm across and arranged in opposite pairs on the stem.

On young growth, the leaves may be in groups of three and much larger than the leaves on more mature growth. The characteristic large size of the young growth is exploited by gardeners. By pollarding the tree they ensuring there is vigorous new growth every year. Pollarding is the process of trimming back the branches to the trunk of the tree so that new denser growths will occur. By dong this massive leaves are produced (up to 60cm across). These are popular in the modern style of gardening which uses large-foliaged and “architectural” plants.

The flowers of the Princess Tree bloom before leaves are produced. In early spring they grow on panicles 10-30 cm long with a tubular purple corolla 4-6 cm long. The fruit is dry and egg-shaped about 3-4 cm long and contains 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.

Uses

In China, an old custom is to plant a Princess Tree when a baby girl is born. 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 Princess Tree and only when a good ruler is in power. Several Asian string instruments are made from the Princess Tree, including the Japanese koto and Korean gayageum zithers.

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. This, together with seeds released by specimens deliberately planted for ornament, has allowed the species to become an invasive weed tree in areas where the climate is suitable for its growth, notably Japan and the eastern United States.