Tuesday, 25 December 2012

Merry Christmas

Season’s greetings one and all! Merry Christmas and a happy new year! I am unfortunately unable to offer any particularly festive images of Kew, so instead here’s another look at dear old Hidcote under snow. See you in 2013!
Sign reads: ‘We are sorry the garden is closed today’

The Stilt Garden with the laden hornbeams

Gateway leading from the Theatre Lawn to the Beech Alley

The Theatre Lawn!

View from the top of the Long Walk, the incline always seemed more extreme from this end

Rose Walk, with a pleasing smattering on the Irish yews

Morning light over the Lime Avenue

Thursday, 20 December 2012


Undoubtedly, one of the highlights of my time at Kew so far has been maintaining and becoming acquainted with the large Passiflora collection held in Zone 9! Passiflora is a genus containing over 500 species that are mostly found in tropical South America, and to a lesser extent in places such as North America, Southeast Asia and Australia. The simplest way I can describe them is as the tropical version of Clematis; vigorous blighters that clamber about all over the shop on tendrils, and with delightfully beautiful flowers that are consistently showy and fascinating across the genus! These amazing flowers have been captivating horticulturally-disposed eggs for centuries, as far back as the 16th century they were being lauded and praised for their beauty. Spanish Jesuit priests were convinced that these flowers symbolised the Passion of Jesus Christ, and attributed the complex flower parts to the various elements involved in the crucifixion. The Latin word passio means suffering, and this religious association continued in the naming of the genus by Linnaeus.

The stereotypical Passiflora bloom is large and showy, with a crown around the flower known as the corona that acts as an attractor and landing pad for pollinators such as bumblebees. An inner corona leads to the nectar, which the bees extract in the traditional manner with their tongues! This corona is stunted in species pollinated by hummingbirds (landing pad not required), but the floral tube leading to the nectaries is much longer, about 10cm, to account for the long beak of these graceful birds. The arrangement of the male and female flower parts is quite unique, with the male anthers pointing down towards the flower. Pollen transfers from these on to the backs or heads of bees and birds respectively, as they brush against the anthers before consequently brushing against other flowers when they cheerfully continue on their pollination rounds. The female parts are also conspicuously arranged, generally seen in threes and always standing upright as the flower opens. A period of time elapses after opening, this quirk dependent on the particular species, after which the stigma then also begins to slowly point down towards the flower. This brings it slightly closer to the action where the pollinators are drinking nectar, and enables it to better receive pollen from the slurping bees and birds. The aim of this remarkable skulduggery is to limit the chance of self-pollination, by leaving a window of time in which the pollen on the anthers can be removed by the first eager visitor. Appearing after this raises the possibility of coming into contact with pollen from another flower, which increases genetic variation and creates stronger plants in the next generation!

 In terms of cultivation, one of the most enticing aspects of Passiflora is their ability to flower well as container grown plants. The majority of the specimens in Zone 9 are growing in 5L pots and are regularly hacked back throughout the year to keep their vigorous growth in check, but in spite of this apparently rough treatment a large majority of the species flower well, and even at this time of year with the ever-reducing light levels. For growers in England, containers and a greenhouse are generally required to get near these predominantly tropical plants. There is happiness in the world however, as near-hardy specimens are available to enthusiasts in our less balmy climes, with Passiflora caerulea the hardiest for cultivation in England. This species will endure temperatures below freezing when planted in a sheltered spot and offered some protection; with good drainage the key to limping it through our cold and damp winters (wet cold quickly croaks the roots). Fortunately P. caerulea hybridises readily, and the hardiest hybrids available are those involving this species in the parentage. P. ‘Amethyst’ and P. ‘Clear Sky’ are two notable examples, but there have been over a hundred created (where there is a will, there is a way!) An unheated yet frost-free greenhouse or windowsill would obviously be an ideal situation to overwinter a container grown P. caerulea hybrid, brought in from the garden after a prune that results in at least some green leaves being left on the plant, and tied-in to four foot or so of canes to support any winter growth.
I am smitten, as this rambling on indicates! Enough jabbering, here is some Passiflora glory!
Passiflora umbilicata, a glorious specimen from Argentina and Bolivia. Pollinated by hummingbirds, it is unique amongst Passiflora as all other species pollinated in this way are either red or pink

The ripening fruit of Passiflora foetida. The Latin epithet ‘foetida’ normally relates to something foul smelling, in this case the flowers smell sweetly but the hairs on the leaves pong when disturbed

Another of the hardier hybrids, P. x violaceae, British-born in 1819 and the first hybrid ever created by crossing P. racemosa and P. caerulea. Flowering in Zone 9 for the past three months!

Many red-flowering species are difficult to maintain, but Passiflora ‘Lady Margaret’ is amongst the hardiest and flowers freely

Passiflora siamica, a rare gem from China. Last week a Passiflora expert spent almost thirty minutes in Zone 9 photographing these blooms, and actually picked three ‘to take home and dissect’! This eccentric mayhem is explained by the uniquely large number of male and female flowering parts

One of the most wonderful hybrids housed in Zone 9, Passiflora x belottii, born from a cross between P. alata and P. caerulea. Sweet smelling, very free-flowering, and the contrasting pink petals and white sepals are a thing of beauty!

Passiflora organensis with the anthers pointing downwards and loaded with pollen, ready to brush on to the head of the pollinator as they reach in to claim their nectar reward

Several of the smaller flowered species have a rich, deep purple to the undersides of the leaves. This is Passiflora vespertilio, widespread in South America and not tolerant of cool temperatures. Latin for bat is vesper, while vespertilius means ‘resembling a bat’; in this case relating to the outline of the foliage

Another dalzzling hybrid, Passiflora ‘Red Infinity’

Passiflora herbertiana is one of three species found in Australia. Aborigines eat the fruits! This chap is a real bloodhound; self-fertile, relentlessly free-flowering (sprung straight back into bloom after a recent chopping back), and very tolerant of cooler temperatures. Worth a look!

The forming fruit on a recently pollinated flower. After many failed attempts at crossing species this fruit has finally set for me! A long process ahead of seed ripening, germination and seedling growth, but Carlos is optimistic about the parents I chose and the potential hybrids

Another of the slightly hardier species, Passiflora amethystina, that flowers extremely well when grown in a pot with blooms up to 10cm across!

The foliage of Passiflora species is the most varied of any genus, often displaying dramatic lobes such as here with P. obtusifolia. This variation creates a disguise, in an attempt to bamboozle Heliconius butterflies. These beautiful creatures lay their eggs on Passiflora leaves, and the following caterpillars feed ravenously! Other defences used include hairy leaves that trap caterpillars, foliage with toxins, and nectar glands on the leaves which attract ants and wasps that will naturally predate caterpillars

Dryas iulia, the Julia Heliconian, native to Southern and Northern America and seen here at Stratford Butterfly Farm

Heliconius ismenius, the Tiger Heliconian, native to similar regions and again seen at Stratford Butterfly Farm

Wednesday, 12 December 2012

Autumn interest

Outside of the greenhouse, the Kew landscape has recently been going through some staggeringly beautiful and dramatic changes. The place is absolutely chock full of mature and magnificent trees, so the autumn colour is both unique and utterly glorious! There are literally thousands of trees here; The Arboretum holds the lion’s share of the site with the garden display areas dispersed in amongst it. The long history of the gardens means that many of these specimens are beasts, and considered champions within British arboriculture! This season of radiant autumn colour has already given way to winter structure, but with the strong possibility of snow on the horizon I am looking forward to smothered branches and icy silhouettes!
Several majestic specimens of Taxodium distichum dominate the banks of the Palm House lake, what a tree!

Down by the main lake, Taxodium distichum is collapsing into an autumn drop while the evergreen Taxodium mucronatum holds things together with a stiff upper lip

A monstrous Larix decidua towers over Prunus serrulata ‘Taki-nioi’

The shocking red foliage of Sorbus commixta!

An autumn standard, the Japanese Maple, Acer palmatum

The foliage of Cotinus obovatus displays these curious markings in autumn, the tree appearing to drain the life out of each leaf

Over by the Palace, a stand of Liquidambar styraciflua

This is Pterocarya x rehderiana, the foliage delightfully reminiscent of Wisteria autumn colour

The Temple of Aeolus perched on the mound that affords some good views of the Palm House, and an ancient Acer campestre

The shimmering display of Carya glabra, which has the charming common name of the Pignut hickory and is native to the Eastern United States

Prunus serrulata ‘Tai Haku’ lights up the Japanese Garden and Chokushi-Mon (the Gateway of the Imperial Messenger)

A chap named David Nash has been displaying some of his famous sculptures across the garden. He works mostly with wood, and these organic shapes have looked quite fantastic amongst the frosty Kew landscape

Amongst all of the colour, some incredible seed pods have been seen about the place! These are from the Goldenrain tree, Koelreuteria paniculata. Apologies for the quality of the image as these were taken with my field telephone device

Paulownia tomentosa fruit is egg shaped and with tiny, papery seeds. These seed pods and fruit were brought together for our recent identification test, every fortnight we have a ‘plant ident’ featuring a test on 20 Latin names from a possible list of 40. This includes genus, species and family

Finally this is from an Aristolochia species. Such detail and colouring, it looks more like an expensive Christmas tree decoration!
One of my favourite Hidcote blog posts was from this time of year; please click here for more autumn mayhem.

Wednesday, 5 December 2012

Zone 9

This week I have been launched like a t-shirt & short clad rocket into the ‘Great Glasshouses’, having been posted to the Tropical Nursery with responsibility for ‘Zone 9, woody tropical’. The Tropical Nursery contains 21 separate zones, all independently controlled and heated to accommodate the exotic collections contained within, with species from the four corners of the globe being nurtured here!

Although the largest glasshouse at Kew this area only opens to the public once a year, with us mostly behind the scenes ferretting away to maintain the collections, and supply plants when needed to the Palm House, Temperate House and other public display houses. My zone harbours some delightful specimens, including a collection of Passiflora species and hybrids, large collections from the island of Mauritius, three benches of assorted tropical climbers and a healthy gang of small trees. These coves will not settle for any less than around 22°C and 90-100% humidity, which hopefully explains this issue of my extremely casual and informal attire! The plants here are dashed interesting and rather rare, with a number of species, particularly amongst the Mauritius collection, either extinct in the wild or down to one or two remaining plants. This is quite a change of focus compared to the work at Hidcote, with plants being grown to conserve the species and have them readily available for propagation, instead of cultivation for beautiful flowers or long season of interest. Much of the Mauritius collection was brought back as seeds and cuttings from expeditions to the island by my day-to-day Boss Man, Carlos Magdalena. This egg has been described by the BBC as ‘the plant messiah’ on account of his propagating several rare species previously at risk of extinction. Although I am so far unfortunately unable to report any miracles, I can tell you he is inspiringly enthusiastic about plants and propagation, and basically seems to have the ardent patience and extensive knowledge base to fathom out ways of propagating these rare plants which have never been seen before in cultivation.

I will be featuring some more of the action from the Tropical Nursery before my placement ends, but here is an initial introduction to some of the plants residing here!

The tropical mayhem of Zone 9!

One of the many assorted climbers here, the large flowered Stictocardia beraviensis

Caesalpinia pulcherrima is a glorious legume with these striking whirls of flower

Several water tanks house lotus and water lily specimens; and this dainty chap is the world’s smallest water lily, Nymphaea thermarum

Some days with the light streaming in it’s easy to imagine being lost in a jungle!

Passiflora xiikzodz is a delicate little egg, and forms one small part of the huge passion flower collection

Several of the plants in the zone are harvested by humans, with the cotton wool plant Gossypium herbaceum utilised across Africa and Asia

Antigonon leptopus is an amazing climber known as the coral vine. It can be a weed in places like Florida, but in less hardy climes I suspect it may have the vigour to be used as an annual like Cobaea scandens, etc.

Hibiscus liliflorus; a combination of Latin words to set the old pulse racing! This beautiful gem is now extinct in the wild, but grown in gardens all over Mauritius

This drooping glory comes from India and is Thunbergia mysorensis

Hibiscus species are also well represented in the collection, with H. arnottianus seen here from Hawaii

Tropical insects and animals are unfortunately lacking in Zone 9, but we do get the odd cockroach mooching about the place!

Carlos and myself in the full panoply prepared for spraying!