My paulownia is in flower. Before you yawn too obviously, at a gardening bore droning on about their favourite plant of the moment, just ask yourself  if you’ve ever seen one in blossom yourself? If not – and you’d definitely remember if you had – then you have missed one of the great marvels of the world of trees.  It is simply spectacular at this time of year looking up and seeing the soft purple trumpet flowers against a brilliant blue sky.

Read on to find out more about the history and uses of this extraordinary tree….

 

 

I am not clever enough to be a botanist or specialist in taxonomy but as far as I can make out the genus Paulowniceae contains between 6 and 17 species [even the experts disagree] and although fossils of paulownia have been found in North America most species are generally considered to be natives of China, although they have long been cultivated in Japan and Korea as well.

The best known and most garden-worthy species is P. tomentosa,  [from the Latin meaning ‘covered in hairs’]  which was described first as Bignonia tomentosa by Carl Peter Thunberg in 1784.

Thunberg was a Swedish naturalist  who had studied with Linnaeus. He became a ship’s surgeon with the Dutch East India Company and spent three years in their Cape colony where he earned a reputation as a plant collector. In 1775 he was sent to the small Dutch trading post at Dejima in in Japan. Dejima  was an artificial island in Nagasaki Bay where a small number of Dutch traders were permitted to reside, but very rarely allowed to cross the bridge to the mainland.  These strange conditions were accepted since Dejima was the only western point of contact with Japan. David Mitchell’s novel The Thousand Autumns of Jacob de Zoet conjures up this  bizarre and isolated world brilliantly.

In 1776 Thunberg was allowed to accompany the leader of the Dutch settlement on a  visit to the shogun at Edo, the Japanese capital, and on the way collected many plants.  He left Japan the following year and in 1784 published : “Flora Japonica” the first detailed description of the flora and fauna of Japan, although many, including paulownia, were actually Chinese plants which had been introduced into Japan.

Thunberg may have described paulownia but does not appear to have bought seed home with him, and it was not until 1834 that seed finally reached the west.  When it did, it did not come from its native China but from its adopted  Japan where paulownia had long been cultivated and incorporated into Japanese culture.  Whilst the national and imperial flower is the chrysanthemum, paulownia serves as the symbol of the office of prime minister.

 

 

 

 

The first consignment was sent to the Jardin des Plantes in Paris. Henri François Neumann, superintendant of the hothouses there, wrote:

“Some time ago I received a foreign seed, which produced a tree. This tree I kept two years in the hot-house because I had but a single specimen, and I was fearful of losing it.  But soon after finding that the shelter did not suit its habits, I planted it in the open air.  There it found a temperature similar to that of its native country. It soon developed itself with great luxuriance.  The leaves became at least ten times larger than when in the hot house, which was probably too warm for it.  Here it soon showed its flower and fruit and was in fact the fine tree from Japan to which botanists have since given the name of Paulownia imperialis.  I am far from wishing to boast of having naturalized or acclimated it, since we cannot say that its nature has changed, or that it would not have stood at first with the greatest facility in our climate.  But we can say that it finds at Paris almost the same temperature as in Japan, and that it thrives very well here.”[ The Horticulturalist and Journal of Rural Art and Rural Taste, 1846, Vol.1, p.38]

It flowered for the first time seven years later, and by 1842 it was 20 feet high with leaves 2 feet in diameter. That year Neumann collected the seed  and used it to raise over 20,000 seedlings. It did not take long for paulownias  to become a favourite street tree in many parts of France.

A specimen  was introduced  to the Horticultural Society of London’s garden at Chiswick’s in 1838 and by the early 1840s it had reached the United States.

 

The genus  was renamed Pavlovnia by the German botanist Philip Franz Siebold after Princess Anna Pavlovna, the daughter of Tsar Paul I, who married into the Dutch royal family and later became Queen of the Netherlands. This was quickly converted into the Dutch rendering of Princess Anna’s name –  Paulownia.  Because of its royal associations one of its common names is Princess Tree. Others  include Empress Tree and Foxglove Tree.

 

Like Thunberg, Siebold worked as a physician for the Dutch East India Company at  Dejima.  Arriving there in 1823 Siebold created a tiny botanical garden on the small island which can be seen in the earlier image of Dejima. It contained over 1000 native plants. Later he smuggled out seeds of many plants including hosta, hydrangeas, azalea,  as well as the Japanese larch,  tea and last by no means least Japanese knotweed! He was expelled from Japan in 1829  and returned to the Netherlands where he began publishing his Flora Japonica in 1835,  in collaboration with the German botanist Joseph Zuccarini, although not all the volumes were completed until well after his death.  The book was also dedicated to Anna Pavlovna. A description and plate of Paulownia tomentosa as P.imperialis appeared in the 1841 volume.

From then on information spread rapidly.  including  appearances in the French botanic magazine  Annales de flore et de pomone in 1842, and  in Curtis’s Botanical Magazine in 1852.

I can remember the first time I experienced the extraordinary sight of Paulownia tomentosa in full bloom. It was in Oxford Botanic Gardens and I rounded a corner by the rock garden and was overwhelmed by a huge shimmering purple haze. Getting closer I saw the tree was leafless but covered in masses of foxglove like flowers arranged in pannicles, and closer still I got the hit of its perfume. Since then I’ve been hooked.

It was the first tree I planted in my own new garden and it occupies a very prominent position. The flowers are not its only virtue.

Once they are over huge dinner-plate sized leaves, even larger than catalpa, begin to appear, and then eventually small brown hooded seedpods which rattle enthusiastically in strong winds.

 

Next year’s flower buds form during the autumn, in candelabra like bunches, and over-winter.  I have seen reports that they can be damaged by harsh winter weather, but mine have survived intact despite terrible winter storms and temperatures down to -17C.

Some people are not quite as enthusiastic as me.  Christopher Lloyd, for example,  claimed never to be able see the blossom to advantage. ” ‘Surely the paulownia should be flowering by now’ I would tell myself each spring and sometimes it was, but it was always a case of me reminding the paulownia, never the other way around. I would look at it against a stony blue-grey sky and its foxglove funnels were almost exactly the same shade. Against a clear sky they just looked dirty. Perhaps from a helicopter they looked delightful against spring green but that wasn’t good enough for me. The paulownia went.” [In My Garden Chapter about September].   I know its terrible to disagree with Christo, one of the greatest gardeners of the 20th century but  …. his loss entirely I’m afraid!

Lloyd may have cut down the specimen tree at Great Dixter but he still used paulownias in his famous revamped tropical garden, where they were grown entirely for their foliage and coppiced every year.  [One can be seen right at the back of the photo.] Plants treated like that can reach more than 3m in one year making it a great ‘spot’ plant.

Other species of paulownia can grow even faster, so that some can be harvested for their timber in as little as five years, making them useful as well as beautiful. Since  they then  regenerate rapidly  from their existing root systems, they have been nicknamed   “Phoenix trees.”

 

Paulownias are the world’s fastest growing hardwood trees. The entire genus is tolerant of pollution and  not fussy about soil type, while the roots are a good counter to erosion, so making it a good  pioneer plant in re-afforestation schemes.

Its nitrogen-rich leaves provide good fodder and its wood is  extremely lightweight but strong and resistant to rot.  Not only that but it is extremely buoyant and does not absorb water. This makes it very suitable not only furniture, but also boats and even surfboards and skateboards.

More importantly  it is a good  windbreak in agro-forestry where other crops can be interplanted through paulownia plantations, substantially raising yield.  More recently it is being used for biomass. For more on these uses of paulownia see:

http://paulownia.info/paulownia-information

http://www.fadr.msu.ru/rodale/agsieve/txt/vol4/issue1/1.html

While these uses might make it, like eucalyptus, a favourite tree in many parts of the world, its advantages are outweighed in others by its potentially invasive nature. Paulownia self-seeds freely under the right condition, and suckers furiously if the roots are disturbed or damaged.  As a result it has been declared a noxious weed in many of the southern and eastern states of America. In case you’re wondering how it got out of hand there in the first place, its because the seeds  are light and fluffy, rather like kapok, and so were used as a cheap packing material for protecting goods in transit from the far east. They were either then thrown away or ‘escaped’ en route  along the major railway lines.

But its not invasive in Britain!  Even so, it was not widely planted after its introduction. Angus Webster the early 20thc  author of several books on trees wrote in London Trees [1920] that so few paulownias had been planted in London that it was impossible to tell if they would be suitable for cultivation in the capital. He did however note that there were several  specimens in Regent’s Park -“the largest is growing on a mound in the flower garden and has a well developed stem that girths 5 feet 10 inches at a yard from the ground, the branches having a spread of fully 36 feet.”   Other ‘healthy specimens’ were noted in outer suburbs such as Wimbledon, Putney, Roehampton and Hampstead, but Webster says he “was not aware that is to be found  in the more densely populated or smoky parts of London.”

For the full entry see: https://archive.org/stream/londontreesbeing00websrich#page/90/mode/2up

Since Webster’s day things have changed  somewhat and landscape consultant John Medhurst has written a fascinating and comprehensive guide to London street trees. In his entry on paulownias he writes: “I imagine that the first Horse Chestnuts in this country must have been greeted with as much delight and amazement as this tree engenders, but I hope they will not become as widespread, for part of the excitement in seeing them is knowing them to be special and suited to an important location.  Paulownias planted just as a pavement tree… seem misused and out of place.”

To see more of John Medland’s “A Capital Arboretum: Trees in London” see:

http://www.johnmedhurstlandscape.co.uk/trees/

 

Our database lists just 10 historic parks and gardens with specimen trees, although I’m sure that’s just the tip of the iceberg, so if you know of any more good examples please let us know.

There are, for example, several in Scotland, including Craig House at Montrose and Fordell Castle, although I can’t find any photographs of them.

http://www.parksandgardens.org/places-and-people/site/8205

http://www.parksandgardens.org/places-and-people/site/8862

Nor can I find images of specimens in public parks such as Hotham Park in Bognor. There the paulownia was probably planted by William Fletcher the last private owner in the first part of the last century, as he was a great plantsman and worked closely with Kew to create the horticulturally rich collection of trees, shrubs and ornamental plants that are seen in the park today.

http://www.parksandgardens.org/places-and-people/site/5318

However I did manage to find a couple of images of paulownias  in university grounds. Reed Hall, a Victorian guano magnates estate, now part of the main campus of Exeter University   is still home to many rare trees and shrubs and includes a fine paulownia.  More recent ones have been planted at both Emmanuel and Churchill colleges in Cambridge.

 

 

UPDATE:  20th May. Thanks to Robert Peel for news that there is also a good specimen in Bute Park, Cardiff, near the bridge which connects that park to Sophia Gardens….and for the photo below of the paulownia at
Magdalen College, Oxford.

 

I did think about starting a paulownia fan club but somebody has beaten me to it…. so if you really want to find out more take a look at

http://www.paulowniatrees.org