A Northumberland Alpine Gardener's Diary
This entry: 11 March 2007 by John Richards
Northumberland Diary. Entry 27.
It seems a long time since I mentioned the pond. Can I remind you that the liner of the original quite substantial affair had failed for the second time after eight years or so, and that we had painstakingly emptied it and its menagerie and bought some much smaller semi-rigid shapes. These had been put into position and the wildlife restored several weeks ago. Since then I have used odd moments to adjust the levels by altering the position of the semi-rigid flange by propping stone under, or on top of the edge. When I was quite happy with the levels, I have been able to hide most of the 'workings' with either Yorkstone pavers or river boulders/pebbles. The latter are quite exceptionally expensive to buy, so I have 'acquired' a small number from a local source. The pump has now been reattached to the pipe which leads from the pond to the urn, and the small cascade works satisfactorily.
And a pet theatre
I had already shown a picture of the new peat block area, but most of the petiolarid primulas grown here are now in flower. The effect is curiously similar to some of the Auricula 'theatres' beloved of the Victorians and occasionally seen at Shows even today, perhaps because the dark background shows off the flowers so well in each case. I have now removed the covers from this area and the other specialist areas in the garden where I grow asiatic primulas. This is a week or two earlier than in most years, but the season is well advanced. I was delighted to see that all the Primula sonchifolia seedlings have survived, and many of the mature P. calderiana and P. tanneri plants are showing early signs of life (these disappear completely in winter).
Hybrid vigour is a well-known phenomenon amongst alpine gardeners, although the scientific basis of the effect is not well understood. There are many examples amongst primulas, and one of the most marked is the lovely blue clone named after the west Highland garden that first distributed it, 'Arduaine' (pronounced 'ardoonie'). This plant is completely sterile and very vigorous. Its parents are almost certainly the west Bhutanese P. whitei, which has proved almost completely ungrowable, and P. bhutanica from east Bhutan and south-east Tibet. The latter species can only be kept in culture by constant renewal from seed (as is also the case for P. sonchifolia). Interestingly enough, only pin-flowered forms of P. bhutanica remain in cultivation, but if crosses are made between them a reasonable seed-set can be achieved. Store the seed in the fridge from the moment it is collected and sow in January.
However, from the gardeners point of view, the hybrid 'Arduaine' is greatly superior to any other Himalayan blue primrose, and it is becoming quite widespread. It makes an excellent plant for exhibition, and it is one of my exhibition plants that is figured here.
Pins and thrums
I assume that many readers already know that, as intimated above, most primulas set much better seed when 'pin flowered' plants (with a long style and short anthers) are crossed with 'thrum-flowered plants' (short style and high anthers). You can make the cross either way equally effectively, but it is often easier to take the pollen from a thrum and put it on the exposed pin stigma. Otherwise you usually have to tear the corolla to gain access to the 'naughty bits'. Incidentally, I don't usually use a brush these days, but remove the anther with a pair of fine forceps, an indispensible tool for any specialist gardener.
This photo of P. irregularis shows the two types of flower well (pin on the right). I bought these plants recently from Aberconwy nursery. If the plants are seed-raised, you should find both pins and thrums offered and it really pays to acquire one of each, so that the next generation is assured. As a past Lord Aberconway (no relation to the Nursery!) once said 'the royal road to success in Primula is raising by seed'
What is 'Violet Queen'?
One of the more successful and vigorous crocuses for the open ground here is C. 'Violet Queen'. It is a beautiful plant that has more than a passing resemblance to the very temperamental bog-dwelling C. pelistericus but is much easier to grow. I acquired it as C. sieberi 'Violet Queen', but it flowers later than C. sieberi or C. tommasinianus and at the same time as the C. vernus garden varieties. It is clearly distinct from the latter, being a good deal more delicate, but could well have been derived from a C. sieberi x vernus cross. (However the 'Guru' Brian Mathew has it as a variety of C. sieberi in 'The Crocus', p.65).
With a very few exceptions (mostly Sanguinaria) I loath double flowers. So why do I grow a double Helleborus hybridus? Probably because I am too lazy to dig it out, but for those of you that apparently like such things, here it is!
Dionysias for the idle
Returning from the marvellous Loughborough Show yesterday (one of the best ever, well done Doreen and Eric!), I mused on the cult of the Dionysia which hybridity seems to have raised to a major passion. I wonder if the early growers and collectors in the late '60s and early '70s could have ever dreamt of the regular mounds of pastel colours stretching down large areas of bench that are so much a feature of our early Shows? Such dedication and ability, and so hard to get an award! Plants that would have ben much feted only ten years ago are now completely overlooked. I would rather spend my time in other ways, but I am happy to have a few apparently trouble-free plants planted out in home-made tufa in the alpine house. I figured these back in the early autumn, but D. tapetodes in a couple of forms is in flower now. They would never win an award, but they receive almost no attention and have been there well over two years. By the way, I found out the hard way that like peat these home-made tufa blocks are extremely hard to rewet, and care must be taken that they don't get too dry in winter.
No pot of gold
We expect mixed weather in spring. I hope that this super rainbow photographed from the garden last week is a harbinger of good luck, to all of us!