A North Wales Alpine Gardener's Diary
This entry: June 2014 - Entry 22
Use of the hose just avoided!
Unusually, we had three weeks without rain until yesterday, when we received 28mm in one hour! I had already watered my shallower troughs, nothing else, but was reluctantly (we have a water meter) about to get the hose out when the skies opened. It always amazes me how quickly plants respond and I have often thought of investing in a slow motion movie camera to record it, but have somehow never got round to doing so; perhaps its not too late... Apart from filming plants recovering from drought it would be nice to record such things as the opening of meconopsis flowers, the explosive seed dispersal of geranium and erodium seeds, and the visitations of pollinators. Which reminds me to mention that a Humming bird hawkmoth visted the garden briefly a few days ago and spent most of the time darting between clumps of dianthus, showing little interest in any other flowers in the rock garden.
The star of the show among the alpines this month has definitely been Rhododendron lowndesii, a diminuitve stoloniferous Himalayan rhododendron that has gradually spread to dinner plate size in a partially shaded crevice bed where the soil is not particularly rich in organic matter, The AGS Encyclopedia of Alpines tells us that it grows in Nepal, on banks and grassy slopes, shady ledges and rock crevices, and that it is not fully hardy outdoors and best in the alpine house. Well, it's certainly hardy here, but I should be interested to hear from growers outside the N. Wales 'banana belt' of their experiences in growing this diminutive gem.
Near the rhododendron, in an almost vertical crevice, I have a well established plant of one of my favourite alpines, Physoplexis comosa. The fact that the crevice contains slightly acid soil between slate rocks demonstrates once again the old maxim that plants which grow naturally on calcareous soils rarely require such conditions in the garden, although in some cases they may grow better if the soil is alkaline. I have several plants in similar situations around the garden and all flower freely, though some receive a good deal more sun than others. One interesting thing, to me at least, is that I never get serious problems with slugs and snails eating this delectable plant, which seems to be contrary to the experience of most other gardeners, but that does not mean that all members of the Campanulaceae are immune to damage by molluscs here, Campanula zoysii and C. morettiana in particular being high on the list of susceptible alpines.
Raoulia hectori x Leucogenes grandiceps
As I said in my diary this time last year, New Zealand plants in general like the cool damp conditions in my garden, although they do not generally seed about here with anything like the freedom that they do in some gardens with similar conditions, notably Alan Furness's garden in Hexham. One that I have not shown before is a first class, very slow growing cushion (or more accurately, mat) plant, believed to be a hybrid between Raoulia hectori and the South Island edelweiss, Leucogynes grandiceps. This has spread very slowly (25 x 10 cm in 6 years) into a bright silver mat, showing no sign of flowering, which is probably a good thing as flowers would undoubtedly spoil the symmetry of the plant. It moulds itself beautifully to contours of the rocks between which it grows, producing surface roots as it goes, hence its need for constant moisture. Rooted pieces are easy to detach for propagation, but they must be carefully shaded and watered if they are to make satisfactory new plants.
Growing in a very similar fashion and just in full flower now is a plant of the rose family - a mini spiraea if you like - from the mountains of Western N. America from Oregon southwards to California and eastwards to South Dakota and Texas, Petrophytum caespitosum. This too is slow growing but in this case free flowering, producing its tiny little white tassles on short stems above the procumbent mat of foliage, and they enhance rather than detract from the effect of the plant. There are two other species of Petrophytum (P. cinerascens and P. hendersonii), both of which are much more restricted in their distribution, occurring only in the mountains of Washington State, somewhat to the north of P. cespitosum, and both very similar to that species.
Petrophytum caespitosum (photo taken by Elizabeth
Growing in a much more sunny and dry crevice than the plants mentioned so far is one of the androsaces that are easy to cultivate in the open garden, which generallly means mat or rosettee formers rather than the high altitude cushions. One of my favourite among the mat formers is A. lanuginosa, a native of the North West Himalaya, from the Himachal Pradesh to Western Nepal. There it is found on grassy slopes from 1800m to 3000m, but it is surprisingly easy to please as its receipt of the accolade of an Award of Garden Merit indicates. It will grow quite quickly into a 40 x 40 cm mat, so you need to place it carefully so that it does not shade out slower growing neighbours. The colour comibnation of the flowers and the greyish-hairy foliage seems particularly attractive to me.
And now for a few of the larger shrubs that provide enjoyment in the garden in June, starting with Zenobia pulverulenta.This is the only member of a genus in the heather family and it occurs in the wild from Virginia to South Carolina, growing in damp sandy, or peaty pine barrens where soil fertility is very low. In the garden it slowly builds to make a handsome rounded bush, my largest specimen measuring 1 x 1 m after 15 years. This is the type plant with reddish stems and quite bright green, shiny leaves, tinged too with red above, whitish below, bearing in June numerous bunches of its aniseed scented white flowers. The second photo is of a form I received 3 years ago from the famous Glendoick Nursery in Perthshire, called appropriately 'Misty Blue', for it has heavy waxing on stems and leaves. This flowered for the first time this month and that is why I am showing it to you, hopefully it will become ever more impressive as the years pass, unlike your ageing diarist!
Kalmia latifolia 'Minuet'
Another N. American, but in this case from the eastern states where Its range stretches from southern Maine south to northern Florida, and west to Indiana and Louisiana is the Mountain laurel (Kalmia latifolia); it is the state flower of Connecticut and Louisiana. It has been much selected and bred to increase the size and range of colours of the flowers, but all that I have seen are good. 'Minuet' is a lovely form and the flowers replay close attention both in bud when they resemble nothing so much as the blobs of icing that decorate the top of a birthday cake, and when fully open to reveal a complex pattern of darker and paler shades of pink. Like Zenobia it is easy to please in an acid, reasonably organic-rich but not too fertile soil, and will take either full sun or some shade, at least here in Wales.
Finally, a shrub that you will probably only be able to grow outside if you live in one of the areas favoured by mild winters, Abelia floribunda. This plant is mistaken for a fuchsia by most people who have not seen it before, and it is easy to see why, for a start as the photogphs show the flowers are fuchsia pink! Anyway, it is stunning when in flower, but unfortunately it is nothing of the sort for the rest of the year, having a gangly, weak-stemmed habit that has no appeal. Although I have it growing in the open it would actually look much better trained on a wall where its weak growth would not be noticed, and indeed that was how I first saw it, growing on the wall of a bay window of a house very close to here. Will I move it, of course not, but I may just root some cuttings and try one in such a position....