A Northumberland Alpine Gardener's Diary
This entry: 01 May 2015 by John Richards
Northumberland Diary. Entry 296.
Its a busy time of year, the peak of the alpine season (although the garden itself is as yet far from its best), and yet almost the end of the Show season here in the north. For some reason we now have no northern Show for the five weeks following Chesterfield, and although the dionysias, saxs, Primula allionii and Frits may have finished, there is now a lot more to see, certainly in this northern garden, than during the main run of Shows.
We haven't been here as much as we would have liked, calls of family, and its the dandelion season (!), necessitating an enjoyable field trip to the New Forest. In our absences it has been warm and dry, then frosty. Late frosts are our bugbear here, and often very damaging indeed. Despite our absence I have seen worse. Several rhodos, the Magnolia x soulangeana and some of the young growth on the big Pieris forrestii have been ruined, but not before we had had a chance to enjoy them all for a couple of weeks. Curiously, Rhododendron x fragrantissimum, which is budded well for the first time for several years, has yet to be spoilt. Touch wood!
Here is a view from the terrace before the worst of the frosts.
In the distance you can see one of my favourite rhododendrons which was as good as it has ever been before it was frosted. This is Rh. cephalanthum 'Crebriflorum' which I first knew as a magnificent plant in the centre of Randle Cooke's table bed at Kilbryde.. Like many of the Kilbryde specialities, I had to have it, and to see it as good as it has been this year has been very special. I acquired this more than 30 years ago!
Rhododendron 'Ptarmigan' has also been excellent.
We are increasingly using tulips both in containers, and then planting out the bulbs in their second year into planting circles around trees and the like. I have enjoyed this combination of a tulip (lost its name!) with Narcissus poeticus, and a greigii tulip in a distant container.
Not many tulips are permanent here, but T. uruminensis comes up reliably year after year in a raised bed, and increases modestly. Of course the later T. sprengeri and T. linifolia are good too.
I mentioned frosts and the spoiling of the big Magnolia x soulangeana. Being large, this sticks up into the morning sun which strikes the frost-affected flowers to damaging effect. Our M. 'Leonard Messel' is as yet young and escapes early sunrays. As a consequence it is unspoilt so far.
Luckily our lovely Stachyurus chinensis, grown from seed, is impervious to frost. For maximum effect plant stachyrus where early sun highlights it against a dark background!
A couple of shrubs which live in pots in the alpine house. First, what is proving to be quite a noble Daphne x susannae 'Beauworth. Apart from D. petraea itself, I think this hybrid of the latter with D. jasminea is my favourite specimen daphne, although I have not yet found the trick of getting it to flower uniformly, perhaps because I don't turn it religiously all the year. I am delighted to say that a number of grafts I made of this hybrid last summer are now growing away strongly so I shall try it in the garden. (When I plonked my D. petraea 'Grandiflora' on the bench at Vincent Square last Sunday, Tony Hall said 'Good Heavens, John, I didn't know you grew daphnes!', to which I would reply 'well yes, don't we all, I would hope!'.
Just along from here is a large Lithodora zahnii. This low-level southern Pelponnesian is not hardy here, but under glass has now become a fixture, literally, so that I fear that its Showing days are numbered. I must root some cuttings.
I am growing fond of blue chinese corydalis and am now collecting a few. They seem to thrive here planted out in fishboxes in dappled shade. The one I can't grow is the ubiquitous C. flexuosa which I suspect enjoys warmer drier conditions than we can provide (it does well in the London area!). However, its hybrid with C. cashmeriana 'Kingfisher', raised by the Levers is a good thing. One reason for acquiring it was to compare it with the plant I am growing as C. pseudoadoxa, originally acquired as C. flexuosa 'dwarf form' which is most certainly ain't. As these photos reveal, they are not the same (Kingfisher first, then pseudoadoxa).
Another group I am collecting are the European trumpet gentians. T thought it might be instructive if I posted close up photos of the calyx of three of these (I also grow G. clusii which is still in tight bud). First, the familiar and widespread G. acaulis, also known as G. kochiana. Notice the calyx teeth are less than a quarter of the length of the calyx and are widest above the base.
The western Pyrenean and Picos inhabitant G. occidentalis is very close to G. acaulis, but the calyx teeth are about one third the length of the calyx. Also the leaves are subtly a different shape and colour.
Another Pyrenean, although it also occurs in the French Alps, is G. angustifolia. This has distinctly narrow calyx lobes and leaves, and is very stoloniferous, so that it has rapidly covered a whole trough here, and very lovely it is too.
I took a couple of hybrid pulsatillas down to London (P. halleri x P. 'rubra'). Here is one of them before I dug it up. I mention this as pulsatillas have a reputation for disliking being lifted in this way, but this has not been my experience. As long as the rootball is kept intact, the plant is watered thoroughly from below after lifting and is kept cool and shaded, once it is reinserted into its planting hole and watered thoroughly again it seems to thrive.
Time for some primulas. I am delighted to be growing P. aureata again after many years of absence, and have Cyril Lafong to thank for a seedling. This has thrived kept in a plastic pot in a shady damp spot on the floor of the alpine house (although it likes to be cool, this is not a suitable subject for the alpine garden, perhaps because it usually grows in vertical positions in the wild). It is most usually seen at Langtang, north of Kathmandu in central Nepal, where I heard only today that locals are still cut off from contact as a result of the terrible earthquake. This is the subspecies fimbriata with the cut petal lobes and relatively small orange centre to the 'poached egg' flower.
A plant I grow in a similar way is the Japanese section Reinii species P. hidakana. I believe this to be very scarce in cultivation, perhaps deservingly as I have found it difficult to flower!
Although I and others consigned the western Chinese (mostly west Sichuanese) Nivalid Primula melanops to subspecific status within P. chionantha, I am increasingly of the opinion that it is a good species. The robust, very wide leaves with white farina, big flowers with rounded overlapping corolla lobes and the very narrow calyx and calyx lobes are all distinctive. Seed of wild origin sown last year has already given rise to splendid specimens both in a pot and in the garden.
From much further west in the Sinohamalaya, most if not all the wild locations for P. rosea are disputed petween Pakistan and India and consequently out of bounds. Luckily it persists well in the garden in a cool wet spot. There are some rubbishy forms around, not least for sale last Sunday in London and it is important to try to acquire 'Grandiflora' (as here) or 'Micia Visser de Greer'.
I took this rather startling form of Primula hirsuta to London where it may have raised a few eyebrows! However it is reputedly grown from wild collected seed and the microscopic characters of the marginal leaf hairs are certainly correct for this species.
I don't grow many frits, so that this dwarf form of F. pyrenaica is giving me pleasure. It was rescued from a spot in the garden where it has become very overgrown and had nearly expired. After two years of tlc in a plastic pot inside it is finally showing signs of recovery.
Staying with bulbs, I just wanted to say what a brilliant plant Erythronium 'Pagoda' is. It thrives anywhere, even in these difficult 'dry shade' positions and is robust enough to stand up well to weeds and vigorous ground cover in the more remote parts of the garden. Here it is under a parrotia in dense shade where little else will grow.
Next to here, the mixture of Anemone nemorosa 'Robinsoniana' and A. x seemanii weave a wonderful pattern.
Staying in the wilder parts of the garden, I cannot recommend Allium triquetrum too much. This is not a plant I would trust in a choice spot, nor would I put any in a compost heap, but at least it does not have above-ground bulbils, the bane of the genus, and it makes a terrific statement at this time of year.
This is the one you DON'T want! Allium paradoxum produces pernicious bulbils in the flowering head and is ferociously invasive, colonising the lawn, paths, everywhere! There is a reputedly non-bulbiliferous form, v. normale, which I have even seen on the show bench. I would not trust it with a bargepole, or give it bench space!!!
I am concluding with a very little plant, which I regard as something of a triumph. Most high alpines are not easy plants, and this certainly includes one of Europes most distinguished high scree inhabitants which I saw on the Col de Restefond two summers ago, Petrocallis pyreniaca. I germinated some seed last spring, and planted the young seedlings out on a north-facing sand-bed slope. They have thrived, relatively speaking and have produced a few flowers. I shall write of this slope again, as it is nurturing other interesting and supposedly difficult subjects.