Kent Alpine Gardener's Diary
This entry: 08 May 2014 by Tim Ingram
The fashionable, the curious & the oddball...
Replace these flowers with stemless ones in blue and you have the 'King of the Alps', Eritrichium nanum! What a small step from the ridiculous to the sublime. This diminutive Cerastium alpinum is never going to be grown by many alpine gardeners but is a pretty plant close up in a trough. This is a circumpolar plant growing mostly around the Arctic Circle and rarely in the Alps and Pyrenees, and also in the Scottish Highlands.
With it grows a rather rare and unusual species of Edraianthus, niveus, from the Dinaric Alps in central Bosnia, grown from seed collected by Mojmir Pavelka in the Vranica Mtns (and with some risk from minefields left by the Serbians, see the SRGC International Rock Gardener No. 20, August 2011). Like the related campanulas this whole genus is a valuable one for warm and dry gardens like ours in south-east England. The third plant completes a trio of oddities - a very dark purple-red form of the N. American umbellifer Lomatium dissectum.
So why is it that most gardeners would hardly notice these three plants whilst positively swooning faced with the following three: Trillium grandiflorum 'Flore Pleno', Paeonia tenuifolia and Adonis vernalis? The answer of course is to do with symmetry and size of the flowers quite as much as colour.
Here are three further plants different again and with their own unusual appeal: Phyteuma nigrum, the fern Doodia media and dark leaved Polygonatum x hybridum 'Betberg' (introduced from Germany, if I am correct originally by Beth Chatto). The Plant World never ceases to surprise and specialist nurseries the source of treasures that most gardeners will hardly be aware of, but no less reason to give them a place in the garden.
Gardeners will come at these plants from different directions, unless like me they are relatively indiscriminating in their tastes. However, it is not simply the individual plants themselves that are so fascinating but the stories behind them and the ways they might be grown in the garden and introduced to others with similar interests. Books like 'Cuttings from a Rock Garden' by the great N. American partnership of rock gardeners H. Lincoln Foster and Laura Louise Foster express this beautifully, accompanied by the most exquisite pencil and ink drawings of plants and their garden - but writing like this is rare.
So let's look more closely at some of these plants. The edraianthus for example are a small and distinct group ideal for the sunny rock garden. Graham Nicholls has described them in his fine book 'Dwarf Campanulas', and just a few species like E. pumilio and E. serpyllifolius really stand out, whilst others like E. niveus with which I introduced this diary entry, are of more botanical interest. Those who know them best are the Czech seed collectors, botanists and explorers who have discovered them in Nature and inevitably view them in greater detail than most gardeners. Communication via the Internet enables this knowledge to be shared and amplified much more rapidly than in the past and this whole group of plants is described in some detail by Zdeněk Zvolánek on the Scottish Rock Garden Club Forum under the thread 'Edraianthus Session'. The following pictures of E. pumilio in our garden and E. serpyllifolius, a stunning plant at Blackthorn grown by Robin and Sue White, show how beautiful and free flowering these plants can be. They are readily grown in poor sandy scree in full sun and especially good in troughs.
In the winter the cushion forming E. pumilio dies back to small green resting buds as shown below.
The silver leaved form of E. pumilio shown, however, has often been distributed under the name E. owerinianus and it is only recently that this actually very rare and distinct species from Dagestan (N.E. Caucasus) has been described in more detail and made known to gardeners rather than only knowledgeable botanists. The Czech Zdeněk Zvolánek and Russian botanist Olga Bondareva have both shown drawings of this plant on the SRGC Edraianthus thread taken from the Russian Red Data Book of rare and endangered plants. In a similar way to E. niveus it comes from a region that is relatively inaccessible due to conflict and few other than committed plantspeople and botanists will even be aware of its existance. Like many such rare plants there can be a dilemma between conserving this plant in Nature and providing wider information about it, but when known to so few people such conservation philosophically and practically begins to lose any relevance. It is interesting and good to know about it and its inaccessibility is probably its saving grace.
Phyteuma nigrum, 'Black Rampion', is a very different plant again, probably quite familiar to many gardeners as a summer dormant species that will grow well in grassy meadows, such as this good example at Blackthorn.
It may look rather different to the edraianthus but is actually a member of the same family, the Campanulaceae. Graham Nicholls records a fascinating story of how it has been found in northern Norway, a long way outside its normal range, probably as a result of seed in hay fodder imported from central Europe in the 1940's. Plants have stories to tell! The related and very choice alpine Physoplexis comosa is an excellent trough plant grown in tufa, as shown here in Capt. Peter Erskine's garden, contrasting rather well with a South American Oxalis.
The genus Lomatium is the largest of the N. American umbellifers, hardly if at all cultivated by gardeners, but including (along with related genera) some fascinating plants, and many smaller alpine species from hot and dry habitats. Some like the form of L. dissectum illustrated, and L. columbianum which I have shown earlier, and again here, have very colourful flowers (for umbels!). They will never catch the attention of most gardeners but the family as a whole does in subtle (as well as edible) ways, and we grow many unusual species in our dry Kentish garden.
The Antipodean fern Doodia media - which came from Nigel Rowland, Longacre Nursery, who grows so many good garden ferns - has survived several cold winters in our garden and so seems reasonably hardy; its fresh young growth must be amongst the most colourful of any fern, and its habit small and neat. This would make a lovely part of a spring display of ferns at the Alpine Shows, something that would be interesting to put together in the future, or as part of an exhibit of different woodland perennials.
So finally what about Cerastium alpinum? Has the prospect of the rampageous 'snow in summer' C. tomentosum, which will take over any rock garden, put alpine gardeners off this genus completely? If so they miss out on just one of so many fascinating little plants, not only in this particular genus, that can captivate gardeners in ways very different from the simple response to the glorious flowers of trilliums, adonis and peonies, and make the garden rather extraordinary and unique.
(Prompted by John Richard's pictures of blue corydalis, which are such attractive and appealing plants in the garden, the following picture shows Corydalis mucronipetala - obtained from Keith Wiley (Wildside) at the Spring AGS Show, Rainham, and originally from Gothenberg Botanic Garden. This is one of a number of newly described species recorded by Magnus Lidén and Su Zhi-Yun, see online at www.researchgate.net.
A Rock Garden Bank at Faversham
As a balance to all these rare and unusual plants let me just add a few pictures of this colourful rock garden as you enter Faversham where we live - and maintained by volunteers. Plants growing in the right place and tended with care always brighten their surroundings, and this steep bank never fails to catch the eye and thrill passers by with the potential of rock plants! Even so it can be hard to tempt people in the town to become a little more adventurous in their tastes.