Transatlantic Plantsman

Grow your own holiday mistletoe

Well, the season to be jolly approaches – though quite why we can’t be jolly all the year round I’m not sure… anyway… - with mistletoe soon to be hanging over our heads and a jolly kiss on our minds I thought I’d share this picture and point you to my article on mistletoe in today’s Daily Telegraph newspaper back in England.

This picture of the European mistletoe was taken back in England, in Northamptonshire. It’s a partially parasitic plan which attaches itself to a host plant from which it takes nutrients. Here, a fat clump of mistletoe is growing on a 12ft/3m cotoneaster in a shrub border and looks wonderful amongst all those red berries. Although apple trees are the favorites hosts, mistletoe turns up on a wide variety of other trees and large shrubs especially those in the rose family.

You can read more about mistletoe, and even how to grow it yourself from berries, in my article in today’s Daily Telegraph.

Discovering Scotland’s rarest tree

It’s not often that a completely new wild  species is found in Britain but a new whitebeam (Sorbus) has recently been discovered on an island off the coast of Scotland.

Well, that’s not precisely true. Phil Lusby, who for many years has worked tirelessly both to conserve Scotland’s rare plants and to tell people about them, was examining some pressed herbarium specimens at the Royal Botanic Gardens at Edinburgh. He noticed that one specimen was not what it was supposed to be and seemed to be a distinct new species.

It turned out that the specimen was collected on the Isle of Arran, off the south west coast of Scotland, an area already well known for its unique Sorbus species which are found nowhere else in the world. Investigation of the site, on a hillside in Glen Catacol, revealed that there are just two specimens alive – a third is thought to have been eaten by deer. A deer fence is in place and has been extended. The area is so remote that fencing material had to be flown in by helicopter.

It’s thought that the whitebeams on the island are in an active state of evolution, and that the Catacol whitebeam (Sorbus pseudomeincichii) is a hybrid between the familiar and widespread native Rowan (Sorbus aucuparia), with its clusters of red berries at this time of year, and the Cut-leaved Whitebeam (Sorbus pseudofennica) which is itself a hybrid between the rowan and  the Arran Whitebeam (Sorbus arranensis). Complicated, isn’t it?

These plants have the unusual ability of produce seed without fertilisation (as can dandelions and brambles, amongst other plants) so the offspring will usually be exactly the same as the parent. Seedlings and cuttings are being grown at the botanic gardens so that the trees can be studied more closely – and just in case the deer get through the new fence.

British and American hollies

Back in England… I hear that the frost has finally reduced to a squishy mess those impatiens back in Pennsylvania that had been protected with old bedsheets. It’s now just too cold… The lady’s tresses orchid was still looking good when I left a couple of days ago and is a little more resilient in the face of yesterday’s snow.

First stop here was the Royal Horticultural Society show where the society itself staged an exhibit of hollies. Most of the plants on this fascinating exhibit came from the Society’s west of England garden at Rosemoor in Devon. Curator Chris Bailes, author of the recent holly monograph – perhaps the best plant monograph of the last year – told me that recently flocks of fieldfares and other birds had begun to strip the plants of berries. But there was still plenty to see on the exhibit. [Fieldfares are related to British blackbirds, and the American robin.]

It was especially interesting for British visitors to see the deciduous American Ilex verticillata (first picture), its stems crowded with berries, alongside the more familiar evergreen I. aquifolium and I. x altaclarensis.

Chris also pointed out to me the value of a circular exhibit at flower shows, in preference to rectangular or square stands. He says that visitors tend to follow their way all the way round a circular exhibit but when they arrive at the corner of a rectangular stand they tend to keep walking across the isle to the next display. You learn all sorts of fascinating things at these show…

Rare variegated oak

Finally from my recent visit to Yew Dell Gardens near Louisville, KY – a very rare variegated plant that I found out in the arboretum.

The variegated form of the English oak, Quercus robur ‘Variegata’, is only listed by two nurseries in Britain and very rarely seen in the US. The one in the Yew Dell arboretum was looking rather sad after the summer drought but it had opened a few fresh new leaves so the marginal variegation could clearly be seen. It's unexpectedly attractive.

There are a number of variegated forms of this tree – with foliage splashed, mottled or edged in cream, yellow or pale green – but the names seem muddled and as far as I know no one has sorted them out and matched each type of variegation with the correct name. This cream edged form is sometimes listed as ‘Argenteomarginata’.

At the Royal Botanic Gardens at Kew there is, apparently, a tree which produces green leaves in spring and then when its second flush of foliage appears later in the season the leaves are variegated. I've never heard of such a curiosity before and unfortunately I don’t remember seeing the tree when I was at Kew – although I certainly remember the golden-leaved form growing not far from The Orangery.

There must be some variegated forms of American oaks out there too…

English and Spanish bluebells

First, I apologise for the recent “break in transmission”. I’ve been away for a long weekend at a family wedding where I stayed in what must be the only decent hotel in England with absolutely no internet access of any kind (except for the front desk)! Then a day dashing about, flight back the US, my wife judy’s birthday… Anyway, normal service is now resumed.

Just before leaving our English home for the wedding I visited what may well be England’s finest bluebell wood, Short Wood in Northamptonshire. Voted England’s most popular wildflower in poll a couple of years ago, the bluebell, Hyacinthoides non-scripta, spreads to form wide rolling oceans of colour in many deciduous woods and even along hedges and roadsides. Over half world’s population grows in Britain, and I understand that nowhere else do they spread so prolifically. The bulbs were once used to make glue for book binding.

Studying natives and invasives

After sounding off about the plant police yesterday, I’m struck by the contrast between this attitude and a note I came across on the website of the Botanical Society of the British Isles (BSBI). Here, they list six non-native plants and remark that they seem to be “turning up more frequently than expected”. But they don’t get in a panic and warn us to rip them out in case they take over.

The BSBI has a scheme in which expert plant recorders, professional and amateur, regularly send in plant records from observations in the wild all over the British Isles. These are plotted on maps which are updated weekly, one map for each plant, native and non-native, and they’re free available online.

This scheme has been running for over 50 years and the database now contains 3.2 million records! In conjunction with earlier less comprehensive recording going back centuries, it provides an impressively accurate picture of the way in which plants increase their range and decline. That staggeringly impressive book, The New Atlas of the British and Irish Flora, was based on these records. You can access distribution maps for individual plants at the BSBI Maps Scheme website.

Beautiful blackthorn and sloe gin

One of the most dramatic plants I’ve seen in England on this trip has not been a garden plant – it’s the blackthorn, Prunus spinosa, with great clouds of white flowers billowing out of the hedgerows. It’s the classic spring shrub of roadsides and hedges and like so many natives the plants vary: so today some are well past their best, some are just about to open while many are in full flower. Some are also a clean pure white, others are a dirtier shade.

This relative of the plum and cherry is a traditional, and vital, component of farm hedges – its sharp spines and branching habit help make the hedge a good barrier and it also has other uses.

Hideous daffodils

Driving around England this last week, I’ve found the daffodils especially infuriating. Everywhere, even in relatively remote areas far from towns and villages, the roadsides are planted with daffodils. The trouble is that these daffodils, planted I’m sure by well-meaning local people, are so often large-flowered hybrids like ‘Dutch Master’. They just look so gross and out of place in these more or less natural situations.

If they’re going to plant daffodils, why not plant something less garish, something - dare I say it – like Britain’s native daffodils species, Narcissus pseudonarcissus? Seeing them in the grass at the Harcourt Arboretum a few miles outside Oxford, in the picture,reminds me how appropriate they look.

Pam Schwerdt and Sybil Kreutzberger, formerly Head Gardeners at the spectacular garden at Sissinghurst and my colleagues on the Royal Horticultural Society’s Herbaceous Plant Committee, have long complained about this habit of planting large flowered hybrid daffodils in more or less wild situations – they just look so unnatural! But their protests seem not to have yet sunk in.

So let me add my own encouragement: Please don’t plant large-flowered hybrid daffodils on roadsides, by farm gates, along hedgerows, and in other places populated by genuine wild flowers. If you want to plant daffodils, plant our own native wild species.

Snowdrops escaping from gardens – in the UK and USA

A friend in England has sent me this lovely picture of some snowdrops which she came across – let’s just say somewhere in eastern England. For while most snowdrop enthusiasts have impeccable ethics, such is the lure of the snowdrop these days that there are one or two fanatics who, if I gave the location, would be down there with a trowel in no time.

This mossy ditch is on a rather run down country estate where the huge house is falling into disrepair. Snowdrops have, at some point over the last few hundred years, been discarded from the garden – that is to say, thrown over the fence – and have settled down comfortably alongside the road and hybridised with each other to create a fascinating range of types: tall and short, early and late, large-flowered and small and with a wide variation of foliage and flower shapes.

Stinking hellebores and spurge laurel

Over on the consistently excellent mostlymacro, Dean Stables has been out and about in Yorkshire, as he often is. He's posted a great picture of the rare local native the spurge laurel, Daphne laureola, which also makes a good early dwarf evergreen shrub for the shade garden featuring clusters of greenish yellow flowers with a lovely fragrance. '€˜Margaret Mathew'€™ is an especially bushy and prolific form.

He'€™s also posted some lovely pictures of the stinking hellebore, Helleborus foetidus, in flower although -€“ according to the New Atlas of the British Flora, my bible on such matters - it may not be truly native in his part of the world. But it's revealed as a lovely plant.

It’s impressive in gardens too and can make an dramatic specimen, as my picture of a plant with especially leaden-green foliage shows. Although it'€™s usually relatively short lived, it seeds around so once you have it you rarely lose it. Oh, and it doesn't really stink, Well, the leaves are have a slightly unpleasant smell, I suppose, but only when they'€™re bruised.