Tuesday 31 December 2013

Plant of the Year 2013: Dahlia 'Twyning's Revel'

The first flush of flowers on 'Twyning's Revel' in August, coupled with excellent glossy dark foliage on a stocky plant.
My Plant of the Year 'award' is given to a plant that has given particular pleasure in my garden during the course of the year, performing well and looking good during its season.There were three candidates this year: Salvia 'Amistad' for its exceptionally long period of flower; Dahlia 'Etheral' for its long season of charm and Dahlia 'Twyning's Revel' for its impact over several months. In the end I have decided for 'Twyning's Revel', whose vibrant colour never failed to draw attention, but yet worked well with plants around it.

There are a number of dahlias with the prefix Twyning's, the best known of which is 'Twyning's After Eight' with single white flowers over dark foliage - fun, but I find it difficult to combine with other plants. All have been raised by Mark Twyning, of Winchester Growers in Cornwall, who hold the National Plant Collection of dahlias. An interesting article was written about him and his plants by Val Bourne in The Garden, September 2010. He favours singles in unusual colours, and many of his plants are becoming increasingly well known. I shall certainly seek out others for next year. My plant of 'Twning's Revel' (raised in 2007) came from Avon Bulbs, as a beautifully grown rooted cutting (along with several others), arriving just before I went south for Chelsea. I had the choice of leaving them indoors in sub-ideal conditions (low light and still air), or putting them in the ground directly. As there were signs that the weather was then finally warming up I put them out, where they took off and flourished brilliantly.

The flowers on 'Twyning's Revel' are a mixture of intense pink and orange, but set against the excellent dark foliage the combination works, and at least with their immediate companions in the border there was no clash of colour. I think one would have to work out placement and companions carefully if planting a mass of them, but it would certainly make a statement in the garden. I will propagate mine next year by division of the tubers and by cuttings if possible, but the Avon Bulbs spring catalogue arrived yesterday and I see that they are again offering cutting-raised plants for May delivery. They and Winchester Growers are the only sources listed in the RHS Plant Finder 2013.

Early morning, with Lythrum virgatum 'Rosy Gem'

'Twyning's Revel' lurking behind Sanguisorba 'Blackthorn', adding depth at its base.

The number of ray florets per 'flower' varies somewhat and the presence of an odd curled one or two in the centre would annoy a perfectionist, but in the garden it makes no difference.

This section of the border I can see from my desk: it's fairly obvious why 'Twyning's Revel' caught my eye! This picture was taken early in the morning in early September, of a border planted in May. 

Monday 30 December 2013

Winter work

Artemisia lactiflora 'Jim Russell'

Eryngium cv.
For the past few weeks a succession of storms has lashed the British Isles from one direction or another, with or without much rain and causing varying degrees of damage and flooding. In this area we have been lucky to escape without too much of either but the wind ravaged the standing perennial stems in the garden, leaving most stripped and far from upright. I have written before (13 December 2010) of my struggle to like the fashionable habit of leaving perennials to stand through the winter and, although I keep trying, the longer they hang around the more irritated I get with them. With the wind having wrecked most of what charm they had, I took the opportunity of calm sunny days this weekend to get outside and raze them to the ground - a very satisfying operation, and to my mind, greatly enhancing the garden's appearance. I also had time to break out one compost bin and start mulching the border, another pleasing task with an attractive result. As always, though, there won't be enough to do the whole border, but the other bin will at least enable the patch visible from my study window to be done properly.

The  main border after cutting-back and partial mulching.
Before Christmas I was also able to take advantage of a couple of reasonable days to make progress on the pathways defining the lawn and the gravel beds made in summer. This entails reshaping of the lawn and the drive border, which both need further work, but the coarse flint-gravel path is now in to define the shape to work to. The gravel bed looks a bit barren at present but is full of bulbs and alpines that should perform well next year - many bulb noses are already pushing up promisingly.

A work in progress: the gravel bed for alpines and small bulbs (created in summer), with gravel paths around it and reshaping of lawn and border edges.
Winter-green perennials are seldom commented on but are important garden constituents. This is Geranium robustum.

Friday 27 December 2013

Christmas flowers

Christmas Day flowers and foliage: Galanthus elwesii Hiemalis Group, G. plicatus 'Three Ships', Vinca difformis 'Ruby Baker', Cyclamen hederifolium, Narcissus cantabricus, Arabis ferdinandi-coburgii, fruits of Podocarpus nivalis.
I have been south for Christmas, staying with my parents at Maidenhead and being fed by my siblings in Surrey. The weather was pretty gloomy and dank between gales, but on Christmas morning I took a turn round the garden with a notebook to record what was in flower. I've since lost the notebook, but the list was skimpier than in many years (no Crocus, no Cyclamen coum) and the winter-flowering shrubs had few flowers open. Notable were three clones of Iris unguicularis in flower - a typical form, 'Walter Butt' and 'Mary Barnard', and the big clump of Galanthus plicatus 'Three Ships' by the gate.

Galanthus plicatus 'Three Ships'

Sunday 22 December 2013

Christmas arrangements

+Pyrocydonia 'Danielii', Sorbus randaiensis, Juniperus pinchotii, Narcissus papyraceus, Galanthus 'Three Ships', Iris foetidissima, Pinus densiflora on spalted beech.

Pinus x schwerinii, Sorbus randaiensis, Malus baccata, Eucalyptus gunnii

Salix spp., Alnus japonica, Allium cristophii 

Sorbus monbeigii (?), Abies procera 'Glauca', Abies concolor 'Violacea'

Not arranged, just as it is: onions and shallots.

Saturday 14 December 2013

The Genus Betula

Betula ermanii 'Grayswood Hill' in the Yorkshire Arboretum, October
Earlier this year, the  monograph The Genus Betula  by Kenneth Ashburner and Hugh McAllister appeared from Kew Publishing. With birches now looking good in the beauty of their bark, and recently in the gold of their autumn leaves, this seems a good time to post the full text of a review I wrote for Garden Design Journal, which appeared (slightly abridged) in its October 2013 issue.

‘Long-awaited’ is an apt expression for this book, which has not only been long-delayed, but long-needed as a contemporary review of the whole genus Betula from both botanical and horticultural perspectives.

Curtis’s Botanical Magazine Monographs, published by Kew, are a series of finely-produced, authoritative monographs that continue the tradition of the oldest scientific journal in the world of blending botanical accuracy with horticultural information and fine illustration. The Genus Betula is no exception, being a chunky book full of good photographs and enhanced by many excellent paintings by Josephine Hague and line drawings by Andrew Brown. The authors, Kenneth Ashburner and Hugh McAllister, worked together on Betula for many years before Kenneth’s death in 2010, after which Hugh completed the book, but it is very definitely a joint production bringing together many decades-worth of study, including travel by both authors to study birches in many remote places. One of the results of this is the inspiring arboretum at Stone Lane Gardens, Ashburner’s former home in Devon, where groves of birch saplings from the same collection were planted together. This gives a unique opportunity to study natural variation, but is also very beautiful and well worth visiting. 

Betula medwedewii: a rare species from the Caucasus and eastern Turkey (Yorkshire Arboretum, October).

The diversity of Betula is perhaps surprising. Occurring throughout the cooler – and often coldest – parts of the northern hemisphere, 45 species are recognised here, a mixture of the familiar elegant trees and a number of shrubby species. Although often attractive in the wild, with nice autumn colour, most of the small species are of ‘botanical interest only’, seldom performing well in gardens. Of the taller trees it is clear that there are many possibilities for new introductions bringing new characters to the garden, such as the Vietnamese B. insignis var. fansipanensis with purple-flushed new growth, and for selecting superior cultivars. This book should also serve to remind gardeners of the existence of many fine species that are seldom planted, such as the magnificent B. grossa for which there are no current suppliers in the UK. In these times when tree diseases are so alarmingly prevalent we need as much diversity as possible.

 B. utilis subsp. jacquemontii from the western Himalaya usually, but not always, has good white bark, and numerous selections are valued for this quality. This specimen is at Arboretum Kalmthout (Feb 2013)
The Chinese B. utilis subsp. albosinensis typically has richly coloured bark:, but this and other features form a continuum with the broad species B. utilis. This one from Sichuan is at the reddest end of the spectrum (Yorkshire Arboretum, 2012)

The Genus Betula is principally a botanical book, discussing birches from a taxonomic and biological view. The authors’ reasoning for their opinions is clearly stated and I find it convincing. There are two major nomenclatural changes that will raise a few eyebrows, but from the evidence presented seem sensible: the inclusion of B. albosinensis in B. utilis, as subsp. albosinensis, and the inclusion (also as subspecies) in B. pendula of the Chinese B. szechuanica and the Far Eastern Asian -Alaskan B. mandschurica. In these cases they are taken as representing the extremes in a continuum of variation. For the horticulturist there is a general chapter of the cultivation of birches, reminding us particularly of their shallow-rooted nature and the great desirability of planting them young, and each species has a note on its particular merits or demerits in cultivation. A chapter on birch cultivars by Paul Bartlett, who runs Stone Lane Gardens, is useful but I should have liked to see a fuller description of each, and they are not illustrated, which is unfortunate. All in all, however, this is a useful book and will be a standard reference for years to come.

A less extreme colour form of B. utilis subsp. albosinensis, Purdom 752 from western Gansu, long-known in cultivation as B. albosinensis var. septentrionalis, a name not upheld in The Genus Betula (Yorkshire Arboretum 2012).

Sunday 8 December 2013

Celebrating Sorbus

An eye-catching duo of Sorbus aucuparia in Welburn, North Yorkshire (November).

During the course of the autumn a very frequent remark in any conversation between gardeners has been 'how good the Sorbus have been this year,' so before it's too late I thought it would be good to celebrate this here. A few species have indeed featured as images in the past couple of months but here is a gallery of others, all pinnate-leaved true Sorbus, that have caught my attention. In reviewing my images the other thing worth mentioning is how fine the weather was for so long this autumn, a counterweight to the horrible protracted winter- although that was probably responsible for the superb crops of Sorbus berries by delaying the flowering until it was warmer and there were more pollinators around. These images were mostly taken of trees in the Yorkshire Arboretum, where we have a good collection (though the nomenclature needs work), but some are from elsewhere, as noted.

The western North American Sorbus sitchensis peaked in August
as did S. californica (labelled S. cascadensis), which had lost both leaves and fruits by mid September.

Also looking good early, but continuing for a long time is the dwarf S. frutescens.

September: S. pseudovilmorinii (foreground) and what we have labelled as S. pteridophylla behind - a fine tree with ivory-white berries.

A mystery: this superbly fructiferous shrubby tree is labelled Brickell & Leslie 12545, a number that really belongs to the recently named S. carmesina (which grows adjacent). The collectors told me this week that both pink- and white-fruited species were growing on the same hillside in Yunnan in 1987. Perhaps a berry got in the wrong bag...

The familiar, large-fruited S. cashmiriana at Dawyck, October.

The magnificent wide panicles and big leaves of Sorbus sargentiana make it an outstanding garden plant. This is at Colesbourne Park, October.

Striking clusters of fruit on S. esserteauiana 'Flava' in October

and in late November.

Fading colours but still attractive: S. pseudovilmorinii and S. pteridophylla again, November.

Still at its peak this weekend - the fieldfares and redwings are busily stripping most of the trees now, but seem uninterested in this, which we have labelled as S. monbeigii, Forrest 23890.

Sunday 1 December 2013

Haemanthus deformis

Haemanthus deformis
While hanging up some laundry to dry in the spare bedroom this morning, I noticed the sun was catching the inflorescence of my plant of Haemanthus deformis on the windowsill, so went for the camera.

The genus Haemanthus (Amaryllidaceae) comprises 22 species from South Africa, of which the pinkish-red flowered H. coccineus from the Cape is probably the best known. It was one of the earliest South African plants to be imported to Europe, early in the Seventeenth Century. H. albiflos is also quite commonly grown, as an almost indestructible houseplant, with white flowers in tight heads. According to Dee Snijman, in her book The Genus Haemanthus (1984), H. deformis has at times been confused with H. albiflos but they are quite distinct in many different ways, notably in the foliage. In H. albiflos the leaves are hard-textured and usually recurved, and 4-6 may be present at any time, whereas in H. deformis there are only two at any time. They are softer and firmly adpressed to the ground. In a pot this is challenging for them, so they do their best and mould themselves over the rim. The inflorescence appears from between the leaves in early winter, in its early stages being seemingly squeezed out  in a narrow wedge.

Numerous flowers are held between soft white bracts.
As with all Haemanthus the inflorescence is formed of a number of flowers held between bracts, which with the protruding stamens gives it the look of a shaving-brush. I think H. deformis is a very pretty plant and prefer it to the red-flowered ones I grow, now rather coarsely in leaf having flowered in September. It comes from the Eastern Cape and southern Kwa-Zulu Natal: this plant, given to me by a friend several years ago, was grown from seed collected near the coast in Eastern Cape. It just sits on the windowsill (greenhouse formerly), gets watered occasionally, and does its thing. Eventually the old leaves get ratty and die back, but the new pair has usually replaced them before they are completely withered.

 Haemanthus may not be the showiest of bulbs, and the large leaves of some can be inconvenient, but they are attractive and interesting and have a modest following - there's even a Facebook group devoted to them.

This year the scape has lengthened more than I've seen previously, showing how densely hairy it is.