Kent Alpine Gardener's Diary
This entry: 05 May 2015 by Tim Ingram
The epimedium forming groundcover beneath the trillium is E. pauciflorum, one of so many introduced by the Japanese botanist and planthunter Mikinori Ogisu. This was named only in 1994 and in William Stearn's Kew Monograph is described as known only from the mountain Mao Xian in Sichuan, China.
Stearn's wonderful book - which also briefly covers the other genera of herbaceous Berberidaceae - was published in 2002 and summarises over 80 cultivars of the species (mostly E. grandiflorum) and hybrids, as well as giving detailed descriptions of all the then known species. Since then the number of cultivars has increased greatly because of growing horticultural interest in the genus and the freedom with which the species hybridise, even though individually they do not self-pollinate. (There is significant interest in the genus amongst plants-people in Japan, N. America and Europe, and a lot of information on the SRGC and NARGS Forums in particular - see, for example, a collected discussion at: www.srgc.net/forum/index.php?topic=3374.0).
His book is dedicated to Robin and Sue White and to Darrell Probst, and to Mikinori Ogisu whose wild collections have fired so much of the recent interest in the genus. The open volume shows William Stearn with Mikinori Ogisu and Roy Lancaster in 'My World of Plants' by Mikinori Ogisu (a kind gift from a Japanese friend).
Epimediums really are a fascinating and distinctive group of plants quite unlike almost all other woodland genera. In our garden we have found the Far Eastern species and hybrids quite slow to establish. but reasonably tolerant of our relatively dry summer climate when planted under small deep rooting trees such as apples. These are two very good recently planted examples: 'William Stearn' - raised and named by Robin and Sue White - and a cultivar especially selected for its foliage colour, 'Wildside Ruby' - from Keith and Ros Wiley. That combination of fresh foliage and flowers through April and May gives them immense appeal, only accentuated by horticultural selection.
In Nature different species of Epimedium rarely grow in proximity so natural hybridisation is uncommon. However, Mikinori Ogisu has selected two distinct plants from Mount Omei where E. acuminatum and E. fangii have crossed to give hybrid swarms (E. x omiense 'Akame' and 'Stormcloud') and another, E. x omiense 'Myriad Years', was found and named by Daniel Hinckley and introduced in 2002. This making a vigorous and striking plant in our garden.
The herbaceous Berberidaceae are a group of plants which intrigue because although they may have close similarities in floral and other morphology, and chemistry, some seem very different to the non-specialist eye. The Berberidaceae is regarded as close to the Ranunculaceae, and epimediums with their distinctive spurred flowers are easily compared with aquilegias and delphiniums in the way that the flower has become so intricate compared to a more simple form. Relatives of Epimedium such as Jeffersonia and Ranzania look very different in flower but very similar when you compare their leaves and root systems. Achlys and Podophyllum begin to stretch the botanical imagination further. And Bongardia and Gymnospermium and Leontice? Botany is certainly not a dry descriptive subject at all but a very alive one!
They are also all completely fascinating to the plantsman and, on occasion, very beautiful, as in the case of Jeffersonia dubia 'Alba'.
Beauty is a feature of plants which is hard to fully define. In the Saxifragaceae, Tiarella wherryi and Bergenia ciliata are both beautiful and stars in the garden when in flower now, but in rather different ways.
Flowers though are fleeting whilst foliage very often is not and the autumn flowering woodland saxifrages have a beauty in leaf which persists throughout the year before the flowers even appear. Several of these have been bred by the German Alpine Nursery, Peters, as I described in an earlier Diary entry on Great Dixter.
Late flowering plants like these can be amongst the most valuable of all in the garden because they retain such good foliage for so long, but often need more care in cultivation because they ask for good fertile soil which never dries out. The woodland saxifrages do quite well in our garden even so, but other autumn gems like Cimicifuga (Actaea), which can be extremely beautiful in the right place, are much more difficult to grow in our often summer dry garden.