Transatlantic Plantsman

Variegated rhododendrons - more coming?

Lecturing to a chapter of the American Rhododendron Society about perennials recently proved interesting in way I didn’t expect: I got the chance to talk with rhododendron breeder Tom Ahern. His first interest was in creating yellow and orange flowered types that are hardy in his area of Pennsylvania (zone 6A: -10 to -5F/-21 to -23C), like his ’Orange Ruffy’. Then he became more interested in breeding for good foliage.

I asked him why there were so few variegated rhododendrons – after all, their flowering season is short so variegated foliage would be a good year-round feature. He explained that in rhodies variegation is caused by a virus and is not inherited when hybridizing so you can’t breed for it. He also pointed out that some variegated varieties are rather floppy and they also often revert to plain green; the plain green shoots must be cut out otherwise they take over but this often ruins the look of the plants.

In theory you should be able to create a variegated version of any rhodie by approach grafting. You grow ‘President Roosevelt’(above), for example, and another variety in pots, position them so a stem of each touches, shave a sliver off each stem, and bind the two cut surfaces together. The virus in the sap of one would be transferred to the other. Don’t understand why this hasn’t been done? Any rhodie experts know?

But now that rhodies are being grown in the laboratory in tissue culture, variegated sports are turning up – like 'Claydian Variegated', a tissue culture sport of 'Madame Masson'. These will be genetically variegated so could be used for breeding. Is the variegated sport of ‘Yaku Princess’ (left) virus or genetic?

Either way, as more variegated sports turn up and these are used in breeding we can look forward to more variegated rhododendrons. And any form of good foliage is valuable in plants with such a short flowering season – however flamboyant.

Tom Ahern is also a highly accomplished bird carver.

* More on variegated rhododendrons from Ron Rabieau of Rare Find Nursery (scroll down)

Amazing hellebores - doubles and singles

This post is simply to highlight the amazing hellebores created by Marietta O’Byrne of Northwest Garden Nursery in Oregon.

Here are links to two sets of galleries on their website, you can click image on this page to get an idea:

Gallery of double flowered hellebores

Gallery of single flowered hellebores

It’s too complicated to explain which varieties are available from which retail nurseries, on each side of the Atlantic, a web search will tell you. Please note that although Northwest Garden Nursery will deliver in their local area, they do not operate a mail order service.

Just thought you’d like to see these gorgeous plants, really.

Two great new annuals

There are literally hundreds of new annuals launching for the coming season, but they include two which are noticeable steps forward in breeding in two groups which have already developed a lot in recent decades. And both are from British plant breeders rather than the big American and Japanese breeders.

From the plant breeding company Floranova, comes a completely new type of Nicotiana (flowering tobacco). Although smaller than the big Japanese and American breeders, Floranova has consistently created innovative new types of annuals and has led the world in creating new salvias, new geraniums (pelargonium), new pansies and violas, and even a range of patio vegetables.

Having created the best traditional nicotianas in the world, in recent years Nick Bellfield-Smith at Floranova they’ve brought blood in from less familiar Nicotiana species like N. langsdorfii to create ‘Tinkerbell’ and now from the lovely N. mutabilis to create ‘Whisper’ (above, click to enlarge).

‘Whisper’ has two special features. Like N. mutabilis, the flowers open white then become pink tinted eventually maturing to rich pink. That makes a very pretty picture. Its other special feature is that it seems resistant to tobacco blue mold (Peronospora tabacina), a fungal disease which has been devastating nicotianas around the world and which wiped out the trial of nicotianas at the Royal Horticultural Society’s garden at Wisley a few years ago.

‘Whisper’ is actually a mix of deep pink, rose shades, and appleblossom – which is the one that fades so delightfully. Well worth growing. 

You can find out more about Nicotiana 'Whisper' over on my RHS New Plants blog.

Also from Britain, Charles Valin at Thompson & Morgan has been mentioned here before. He works on a wide range of species – you can read about his work in The Plantsman magazine from the Royal Horticultural Society. For the coming season he has a new viola mixture – in five colours – each colour with a different fragrance. How about that – a few years ago there were more or less no scented pansies and now we have different scents matched to different colours.

You can find out more about Viola 'Allspice' over on my RHS New Plants blog.

Unfortunately this season it seems to be available just about all over the world - except the USA and Canada. Come on T&M, what’s holding you back?

You can order Nicotiana ‘Whisper Mix’ in North America from Michells.

You can order seed of Nicotiana ‘Whisper’ in Britain from Mr Fothergill and Plants of Distinction.

You can order young plants of Nicotiana ‘Whisper’ in Britain from Dobies.

You can order Viola ‘Allspice’ seed in Britain from Thompson & Morgan

You can order young plants of Viola ‘Allspice’ seed in Britain from Thompson & Morgan

You can order seed of Viola 'Allspice' in the rest of the world except North America, from Thompson & Morgan Worldwide.

(Floranova do not sell seed to home gardeners.) 

Two fine Physocarpus (Ninebarks to American readers)

Physocarpus is not a plant that often features on gardeners’ lists of favorite shrubs, on either side of the Atlantic, but the recent arrival of Summer Wine here in the US and the appearance of Lady in Red at London’s Chelsea Flower Show a couple of years back seem to have woken people up to what great shrubs they are – for foliage, flowers and sometimes fruits too.

Here in Pennsylvania we just grow the two in the picture (click to enlarge) – Coppertina, on the left, and Summer Wine. I hope we’ll be adding more. The leaves were picked just a couple of days ago. Coppertina has been a perfect background for Athyrium otophorum with its upright silvery green leaves and red stems while right now the old pink and white single Chrysanthemum ‘Country Girl’ is lovely in front of Summer Wine.

But let’s just clear up the names, for they’re a little confusing as both have been given marketing names (technically called Trade Designations) as well as their cultivar names.

The cultivar name of Coppertina - which, just to confuse matters, is known as Diable d’Or in Europe – is ‘Mindia’ so its correct full name is, in the USA, Physocarpus opulifolius Coppertina (‘Mindia’) while in Europe it’s Physocarpus opulifolius Diable d’Or (‘Mindia’). (Yes, the Trade Designation has to be in a different typeface, too!) Of course here in the US where the species is a widespread native known as Ninebark it’s often just called Coppertina Ninebark.

Either way, it’s a hybrid between ‘Dart’s Gold’ and Diablo (‘Monlo’) rasied in France.

Summer Wine (‘Seward’) is a hybrid between the rarely seen Nana’ and Diablo (‘Monlo’) created by Tim Wood of Spring Meadow Nursery (no retail sales), who’s raised and introduced so many good shrubs, from a cross made in 2000.

And why is it called Ninebark? Well, over at Consider the Lilies where there are some superb pictures of the wild species, Harold Hanson says: “The derivation of the common name is interesting: As it matures Ninebark bark continually splits, leaving ragged pieces hanging from the branches as if it is continuing to reveal new bark—perhaps "nine" times—thus the common name, Ninebark.”

In Britain you can buy Physocarpus Diable d’Or from these RHS PlantFinder nurseries. And you can buy Physocarpus Summer Wine from these RHS PlantFinder nurseries.

In North America Rare Find Nursery list both Coppertina and Summer Wine as well as two new introductions 'Barberone' and 'Center Glow'.

Another man-made “native” plant

A brand new native plant has been given top awards on both sides of the Atlantic. Gaillardia x grandiflora ‘Mesa Yellow’ has won the top award for new annuals in the USA – it’s been chosen as one of four All-America Selections for 2010 – and it’s also won the European equivalent, a Gold Medal for 2010 from Fleuroselect. Both awards are the result of assessment in trials in a wide range of climates and it’s rare for a plant to win both awards so it really must be good.

But does anything strike you as odd about that statement? A “brand new native plant”? If it’s a native plant, hasn’t it been around for thousands of years – by definition?

The citation from Fleuroselect reads: “Like the flat-topped mountains (mesas) after which it is named, this first commercial quality, yellow gaillardia from seed is native of the southern United States.”

In fact ‘Mesa Yellow’ is not native to anywhere, it’s a man-made hybrid. It’s a sophisticated tetraploid F1 hybrid (with twice the normal number of chromosomes) between the perennial Gaillardia aristata and the annual G. pulchella which was created in the high-tech plant breeding greenhouses of the Pan-American Seed Company. Nothing wrong with that - but does it sound like a native plant to you?

It’s true, the original version of this hybrid, G. x grandiflora, has occasionally escaped from gardens into natural habitats over the years and, according to the USDA website, is found in the wild in Indiana, Michigan, New York and Pennsylvania. But that doesn’t make it native, and certainly not “native of the southern United States”.

‘Mesa Yellow’ is early flowering, prolific and colorful – it sounds like a fine plant for gardens, containers and landscape use. But it’s a highly sophisticated man-made hybrid so let’s not deceive gardeners by pretending it’s an American native. It’s no more native than the hybrid petunias and impatiens bred by the same company.

New plants at the largest flower show in the world

My list of all the new plants I spotted earlier this month at Briatin's Hampton Court Palace Flower Show, the largest flower show in the world, is now online on my Royal Horticultural Society New Plants blog. Almost a hundred new introductions are listed - including this weird new allium for cut flower use, 'Dready' -  with links to the individual blog posts in which I wrote them up. Almost all are available from British nurseries, many are available from North American nurseries

Back from New Plants Nirvana

Forgive me, readers, for I have sinned. It’s been nineteen days since my last post.

How time flies when you’re blogging furiously elsewhere. I’m just back from England where I was writing up all the new plants at the largest flower show in the world – the Hampton Court Palace Flower Show - for my Royal Horticultural Society New Plants blog. I haven't yet counted up all the new plants I discovered - it must be nearly a hundred and there were some stunners - but I ran fifty posts in three weeks. Begin here and work back to the starting point on 1 July. I’ll be posting a full list of all the plants I discovered here at Transatlantic Plantsman as soon as I can get it together and add in all the links.

Lots of new perennials including eleven heucheras and related plants from the USA and some intriguing new roses. The Julia Child ('Wekvossutono') rose (above) was launched in Britain for the first time under the name Absolutely Fabulous ('Wekvossutono'). And it’s because roses (more than most plants) have their marketing names changed for the different countries in which they’re sold – no one in Britain has even heard of Julia Child – that we need that cultivar name in brackets carried with the marketing name so we all know they’re the same rose.

Amongst the other plants I especially liked were a new, as yet unnamed three way hybrid Gladiolus; some extraordinary “hairy” alliums for cut flower; a lovely dwarf fragrant Phalaenopsis hybrid; and a new pink trailing Campanula.

Normal service is now resuming here – and I’ll be posting that full list soon. In the meantime, check out the full list of new plants I found at the Chelsea Flower Show.

Buddlejas not growing in patio pots

I’ve mentioned before here how some nurseries stage their plant pictures using cut material to try to make their new introductions look more impressive than they really are. Remember these ligularias?

Well here’s another example.

Over on my Royal Horticultural Society New Plants blog I’ve just written up two new patio buddlejas created by Thompson & Morgan’s Charles Valin at their plant breeding operation in Britain. 'Buzz Magenta' and 'Buzz Lavender' have just been released to British gardeners and they sound very impressive.

But the pictures! These two new buddlejas are so dwarf that they’re ideal for growing in pots on the patio. So someone just went out and cut some branches from the plants, arranged them nicely in a pot and took their picture! And that’s exactly what it looks like. Click on the pictures to enlarge them and see what I mean.

If they grow so well in pots, can’t we have pictures showing them doing exactly that – growing in pots?

British gardeners can order the Buzz buddlejas from Thompson and Morgan. They're not yet avaiable in North America.

New plants at Chelsea - the full list!

OK, I've just posted the full list of all the new plants I found at Chelsea Flower Show this year over on my RHS New Plants blog. Guess how many? One hundred and tenn - that's 110. Roses, perennials,shrubs, clematis, annuals, trees, bulbs, indoor plants plus a cactus and even a new ginkgo.

Some may be familiar to North American gardeners but all were new to British gardeners.

So check out the full list of Chelsea's new plants, then work back through the other 34 posts on new plants from the Chelsea Flower Show - or start with the first from 1 May.

Then from early July I'll be blogging about the new plants at the RHS Hampton Court Palace Flower Show.

Rain, wind and new plants

Here at the Chelsea Flower Show it’s the day before Press Day, judging and the Royal Visit. The rain fell, the wind blew, and an announcement was made that all garden sunshades and patio umbrellas should be folded because of the risk of damage.

Inside the Great Pavilion there were none of the dramas of years ago, before it was a modern prefabricated building, and the three acre canvas marquee rattled and swayed and a huge timber beam fell from the roof.

Many nurseries in the Great Pavilion were flaunting their new plants, which I’ll be reviewing for the rest of the week over on my Royal Horticultural Society New Plants blog, and this seems like to good time to mention just a few of the stand outs so far. When I’ve posted this I’ll be going to bed, sitting up compiling the full list.

A new rose named for the home of Prince Charles, ‘Highgrove’, featured on the stand from Peter Beales Roses and Prince Charles will be at the Show tomorrow to launch it. Two pink flowered hardy geraniums also stand out. Geranium sylvaticum ’Hilary’ from Hardys Cottage Garden Plants and the pink and white bicoloured G. phaeum ‘Mottisfont Rose’ on the Hardy Plant Society  stand which also features the first silver-leaved form of the American native doll’s eyes, Actaea pachypoda – it’s called ‘Pewter and Pearls’.

I was very taken with a huge new picotee Oriental lily from Hart’s Nursery called ‘Melissimo’ in white with a bright picotee edge as well as new bicoloured form of Pacific Coast Iris called ‘Broadleigh Fenella’ from Broadleigh Gardens. There was also a superb Cornus, raised at Rutgers University in New Jersey – of which more another time.