There are many plants that just give me the feeling that they have been in gardens for a long time. Plants which are some how familiar when you first see them but you can not think of what it is in that moment. One such plant for me is Kerria japonica (Kerria) which seems sold but was so new to me. Kerria is closely related to the Raspberries (Rubus) on my youth and the stems and flowers are similar.
Kerria japonica was a confused plant when it was introduced by Carl Peter Thunberg in 1776 and was mis-classified as being a member of the Tilaceae (Linden) family. This happened because the sample which was sent back by him not being complete, the specimen was also the double form ‘Pleniflora’ (Yae Yamabuki). On top of the naming problem was the fact that the plant does not come from Japan originally but was brought in from China as an ornamental shrub for gardens in ancient times. In Japan the single flowered Yamabuki (Mountain Spray) has naturalized and become part of the culture as seen in paintings, poetry and other forms of writing. We know that Yamabuki has been in Japan a very long time as the 11th century novel ‘The Tale of Genji’ mentions the plant numerous times.
It was William Kerr who in 1804 sent a living specimen of the single flowered plant back to the Royal Botanical Garden at Kew in England It was there that Kerria japonica became recognized as being a seperate member of the Rosaceae family. For this reason the plant is now named Kerria to commemorate Kerr.
William Kerr (1779-1814) was a gardener who was born in Hawick on the Scottish Borders and came to garden at Kew. There he was noticed by Sir Joseph Banks who was in charge of sending collectors and explorers throughout the world to bring back plant, animal and geological specimens to be studied and be classified in England. Banks instructed Kerr and then dispatched him to China in 1803 where he was posted at Guangzhou for 8 years. While Kerr was not allowed to travel in China he sent many important plants back from his location which was a port not far from Macao. During the time that he was posted in China it is believed that he became an opium addict and by the time he was re-posted to Colombo, Ceylon(Sri Lanka) in 1812 he was quite ill. In Columbo he was the supervisor of the gardens as Slave Island and at King House. Kerr is considered to be the first professional of plant hunters which have changed gardening as we know it today.
Kerria japonica is interesting in that the most vigorous form is ‘Pleniflora’ which grows into impressive multi-stemmed clumps. Another thing that stands out for this plant is the beauty of them during the period when they are without leaves, what I am referring to is the bright green stems they have and how they almost glow in the gloomy winter and earliest spring period.
Kerria is an easy plant to grow and is easily placed in most gardens. Kerria japonica like filtered sun as its blooms will completely wash out in too much sun. The best locations are under deciduous trees. The like any soil which has average moisture content and will tolerate a drier location when it is established. As you see these plants can become dense clumps, fortunately they are easily pruned after flowers. cut stems by 1/3 to 1/2 or remove them from the base as you would for Rubus(Raspberry) which they are closely related to.
Kerria japonica grow from .9 to 1.8 m (3-6 ft.) tall and about as wide, it has strongly ascending branches. It tolerated temperature down to -15 c. (5 f.) and still bloom very well. Give this plant protection from cold winter winds and late frost pockets as this can damage the flower production and makes them smaller and less in quantity. the plant can be used in many ways, as an informal border, mass planted in mixed deciduous borders and for early spring interest. With the right placement it is a specimen or more usually an accent plant. The Victorian feeling this plant gives off makes this plant an excellent inclusion in heritage and period themed gardens.
Check these links to learn more:
U.B.C. botanical plant of the day: http://www.botanicalgarden.ubc.ca/potd/2011/02/kerria_japonica_pleniflora.php
the ‘In Bloom article from the Japan Times: http://search.japantimes.co.jp/cgi-bin/fe20080402li.html
William Kerr, an important plant hunter: http://en.wikipedia.org/wiki/William_Kerr_(gardener)
………Hope to see you on this path soon………..