A Northumberland Alpine Gardener's Diary
This entry: 01 April 2009 by John Richards
Northumberland Diary. Entry 110.
Global warming and alpine gardening
My friend and fellow Northumbrian Barry McWilliam wrote a thought-provoking article in the most recent issue of 'The Alpine Gardener', and this has prompted me to add some thoughts. Barry said that much as he may agree with the fact that man is rapidly changing the climate, the effects of this change will be haphazard and not easy to predict. Consequently, we should not be in too great a rush to change our style of gardening. He noted that in Northumberland the main symptom thus far has been the lack of 'real' winters. Such are the vicissitudes of publishing schedules that he clearly wrote this before the 'real' winter we have just experienced!
I totally agree with Barry, but would add a further point. It is extraordinary how adaptable plants are to climates very different to those they encounter in the wild, when they are tended by an expert and caring gardener.
In cultivation plants die of being eaten, or of being too cold, too hot, too wet, too dry, overfed or starved, and most actually die of diseases encouraged by the plant succumbing to one or more of these stresses. If we are clever, we can help the plant to avoid all of these dangers, and to thrive in cultivation, whether it comes from high mountains, deserts, tropics or a saltmarsh. Thus, we should not worry too much about how garden plants will respond to climate change. Of course, it is good garden practice to encourage plants that respond well to one's local conditions. However, given the right conditions, we customarily grow plants from very different habitats, side by side. To give one example, I have Morisia monanthos, from the Sardinian seashore, alongside Draba densifolia from the high American Rockies, and neither give much trouble. Here is the Draba.
What actually kills plants, in the wild, is competition. As climates warm, scrub and forests will creep higher up the mountain and will overwhelm tiny alpine plants. (This is how many of my garden alpines die too, overwhelmed by the comperition that I haven't weeded out!). These forests will bring their insects and herbivores, their fungi and pathogens, and vulnerable alpines will be shaded, eaten or diseased out of existence. With care, this needn't and shouldn't happen in the garden.
Back to the garden! It will be no great surprise to learn that by two favourite genera are Saxifraga and Primula, and I guess that many alpine gardeners share this sentiment. I am particularly fond of Greek porophyllum saxifrages, perhaps because I have seen them all in the wild. Some are through now (S. juniperinifolia), while S. stribrnyi, S. corymbosa and S. spruneri are yet to flower. Here is S. scardica, grown from Olimbos seed, followed by S. marginata, the dwarf form introduced by the MESE expedition from 1850 m on Timfi, and var. rocheliana, transferred from Randle Cooke's garden, Kilbryde.
These are all grown in troughs in the garden (mostly fishboxes), which may explain why the last marginata is starting to look distinctly tatty and needs repropagation. I featured S. ferdinandi-coburgii seedlings from the Pirin last year, but they are proving to be reliable performers and deserve a second outing.
.......and some primulas
A couple of rarities to start with. I was delighted to see little plants of P. nipponica on the Edrom stall earlier in the year and the one I bought is starting to flower now. This little Cuneifolia species from northern Japan is a real charmer and has the additional benefit of being homostyle, so it should set seed by itself. The second photo shows that the style and stamens all sit together at the mouth of the flower, aiding self-pollination (as well as being self-fertile).
Perhaps the least-known of the Auricula species is the Croatian P. kitaibeliana. This was given to me by Alan Furness as a small seedling some years ago. He professes not to remember this and doesn't grow the species himself, but I have his handwriting on the label as proof! It is very slow, but does flower fairly regularly.
A third species that is seen far less regularly than 25 years ago is the Himalayan P. boothii. Although not the hardiest, it wintered well under a frame-light. Most forms disappeared from cultivation, riven by virus, and perhaps because not all are very attractive compared with the great firmament of other petiolarids. However, most of the Gerry Mundey 'Tinney' hybrids had P. boothii in their make-up, and we still grow the white and 'Annapurna Autumn' forms of the species, for all that they too are virused. These plants were given to me as a pleasant surprise when I visited the Sussex meeting last September. Unfortunately, they are both thrums, but I have crossed one onto P. irregularis.
I have featured the fabulous P. sonchifolia regularly. I work at it hard and am fortunate that it likes this garden. A number of seedlings are flowering for the first time, and this lovely ice blue is a new break, here anyway.
The story of how this lovely species was introduced back in 1928, when a local forest ranger climbed high into the Burmese Alps in the depth of winter to hack out resting buds from under deep snow, which were packed in ice in bamboo tubes and shipped by the P&O frozen food compartment to the Royal Parks has been told frequently, so I shan't repeat it again (!). Amazingly, this original introduction has survived to today, although there have been successive waves of Chinese reintroductions.
Arguably, the most spectacular asiatic primula is the lovely P. rosea, from Kashmir. Given a really wet site in a fertile heavy soil, preferably a pond edge, this is not a difficult plant, although it disappear in winter and can be tiny in early spring, so it is easy to neglect. There are good and bad forms. This is 'Grandiflora'.
Back to Europe, and here is my favourite European primula, the southern form of the P. auricula alliance that used to be called 'Albocincta'. This is a very different plant from the true P. auricula from the Black Forest, Jura, north Alps and Tatra. The latter is a bigger plant with long green leaves, and funnel-shaped flowers lacking a mealy eye-ring. DNA has shown that the more attractive southern form is quite distinct and deserves specific rank, for which the name P. balbisii is prior.
Two more primulas to finish with, both of which have been awarded an Award of Merit by the RHS when shown from here, and both of which have a long history in this region. The yellow plant was found at Kilbryde in the early 1970's, and was probably part of an experimental collection maintained by J. W. Heslop-Harrison (the 'Old Man') in the 1920's and 1930's and passed on to Cooke. It is apparently P. elatior subsp. pseudoelatior from NE Turkey and the Caucasus. It is an extremely good garden plant, smothering itself with flowers.
While Heslop-Harrison was spreading mayhem at Newcastle (this is quite another story that I may tell some time), David Valentine was presiding over Botany 15 miles down the road in Durham, where he was my Professor, and later, my research supervisor. Valentine was also interested in the evolution and taxonomy of the relatives of the primrose, and in this he progressed a good deal further than his apoplectic rival. Valentine employed several lady assistants to work on this group, and one of these was no less a person than Judy Burrows.
Years later, Judy passed this plant on to me, saying that it had been raised by Valentine himself (remarkable, as he was no gardener), and was the result of an experimental cross between P. elatior and P. juliae. Judy had kept it going after Valentine's death and called it 'David Valentine'. As an ex-Valentine student myself, she thought I should grow it. It is still an extremely good garden plant, although a hungry grower and in constant need of repropagation.