Perennials

Book Review: Peonies by Claire Austin

Peonies by Claire Austin
Peonies is the new book by Claire Austin

It’s peony season and we have a new book on peonies to savour. Written and photographed by renowned peony expert Claire Austin - her nursery lists more peony varieties than I could count – she doesn’t just describe her choice from the thousands of varieties she’s seen and grown over the years. No, she adds the fruits of her insight derived from decades of experience. (Well – enough decades to soak up the experience but not so many decades that… I’ll stop digging.)

The book is, basically, Claire’s choice of peonies, described and illustrated. We know we can trust her choice, and there’s no tricky botanical language in the text to trip us up. In fact I think that she sat on a stool in front of each variety and simply described what she saw. The best way.

But there’s more. So, apart from giving us the description of each plant we learn, for example:
‘Bunker Hill’ “Unlike many red lactiflora blooms, the petals don’t deteriorate quickly when the flower is cut.”
‘Emma Klehm’ “A useful plant for those who want a very late-flowering variety.”
‘Little Medicine Man” has flowers that are small “but produced in great numbers on stiff red stems”.
‘Marie Lemoine’ “Sadly, wet weather can spoil the flowers.”
‘Shirley Temple’ “blooms freely in a partly shaded spot”.’

She also notes, for each variety, whether or not it needs staking and the strength of its scent and lists more than two dozen varieties that she especially recommends for cutting.

Before we come to the descriptions and illustrations that make up most of the book, we have Claire’s advice on growing peonies, a summary of their development over the centuries, and a fascinating account of her own history with these everlastingly tempting perennials.

And I’m pleased to say that she slays the myth about moving peonies: “There is a long-held but totally unfounded gardening belief that peonies cannot be moved.” Got that? “unfounded”.

“Peonies have few ailments,” Claire continues. True enough. But a cut flower growing friend asked me just a couple of days ago why her white peonies were spoiling the purity of their colour with faint red flashes. I had no idea, so I hoped Claire’s book would help. But no luck.

So I’m very happy to have this book on my shelf, to enlighten me – and to steal from – whenever I need. Just one thing: the design is, well, a little bit dull. Modern plant books, including the excellent RHS Horticultural Monograph series and Discovering Dahlias that I reviewed here recently, inspire interest partly because of the elegance of their design. I see no designer is credited on this book. Claire should think about hiring a specialist designer next time.

  • An unimpeachable choice of the best varieties
  • Every variety illustrated
  • Descriptions based on personal experience
  • Thoughtful insight into each variety’s qualities
  • Readable and without reliance on botanical language
  • Design could be more stylish

“Dependable peony advice from our leading expert.”

Peonies by Claire Austin is published by White Hopton Publications at £25. Order a copy from Claire Austin’s Hardy Plants.

 

 


They're all foxgloves, Digitalis - OK?

Digitalis x valinii (centre) and its parents-©GrahamRice-©T&M-©ScottZona

“The smartness and absurdity of plant names” is one of things I’m going to be discussing here on the re-launched Grahams Garden blog, as I did on its predecessor Transatlantic Gardener. We can start with an old favourite given heightened absurdity by the good people at the Royal Horticultural Society – Digiplexis.

“Oh, no!” I hear you cry… Yes, I’m sorry. And we’re going to do Mangave as well…

So. Here’s the story.

Our British native foxglove, a familiar tough biennial, is Digitalis purpurea (above left). The Canary Island foxglove is Digitalis canariensis (above right), a tender rather woody perennial. Charles Valin, then plant breeder at Thompson & Morgan, crossed the two species together and gave the resulting plant the name of Illumination Pink (above, centre). It won the Chelsea Flower Show Plant Of The Year award in 2012.

But, before the Canary Island foxglove was Digitalis canariensis, it had been Isoplexis canariensis – botanists had thought it was sufficiently different from other foxgloves to be in a genus all of its own. Closer examination proved that this was a mistake and the fact that it crossed easily with D. purpurea was one of the reasons that it was re-classified as a Digitalis. The RHS botanists gave the new hybrid the botanical name of D. x valinii, commemorating the breeder who first made the cross.

Other breeders then got in on the act and made their own crosses. And, somewhere along the way, over in the United States, someone decided that crossing two different genera together – Digitalis and Isoplexis – sounded much more impressive than crossing together two different Digitalis and the name Digiplexis® was born. This was much more a marketing exercise than it was a piece of thoughtful botanical nomenclature.

So, let’s be clear. Digiplexis® is an invalid, made up name with no standing whatsoever and which only serves to confuse gardeners. So it was especially maddening to see, just the other day, in the new plant centre at the RHS Garden at Wisley in Surrey, plants labelled Digiplexis® (below). And note the little symbol for a Registered Trade mark. This is a marketing exercise, not a plant name. Aren’t plant names confusing enough, without this sort of nonsense - and without one branch of the RHS muddling up the good sense of another?

But wait, there’s more. Pretty much the same thing has happened with Mangave®. Note that little ® again. This time we’re talking about rosette-forming succulents mainly from arid regions of the Americas – Manfreda and Agave. Nearly twenty years ago it was recognised that there was no justification for keeping these two genera separate so Manfreda was merged into Agave. All very sensible.

But then in the same way as with those foxgloves someone realised that, from a marketing point of view, crossing plants from two different genera was much more impressive than crossing two different species of the same genus. And Mangave® was born, recommended for patio planters.

But there’s payback for this sleight of hand. That first Digitalis hybrid turned out to be far less hardy than was originally announced and so the name Digiplexis® has become attached to plants that fail to make it through their first winter. Something similar will probably happen with Mangave®, which in the UK need grittier compost and more winter protection than is often mentioned.

But haven’t we suffered enough? In recent years plant taxonomists have taken on board the idea that they exercise caution in their decisions about plant names and respect the needs of the wider plant community. The shoot-in-foot madness of trying to make us call chrysanthemums Dendranthema is long gone.

But then someone else comes along and confuses everyone all over again. And the very least that the RHS can do is make sure that it agrees with itself.

Digitalis x valinii on sale as Digitplexis at the RHS Plant Centre at Wisley


First thoughts on trialling Shasta daisies

Leucanthemum- 'Real Galaxy'. Image © GardenPhotos.com

Shasta daisies have come a long way in recent years, with developments on both sides of the Atlantic, and this year I’ve been looking at some of the recent introductions in my new trial garden.

The great American plant breeder Luther Burbank is said to have created the Shasta daisy using some creative, though now discredited, hybridisations between leucanthemums and related genera. He made pollinations between various species and genera but it seems certain that the resulting seedlings were not actually hybrids: pollination but no fertilisation.

The first double-flowered variety was spotted from a train passing through Norfolk in eastern England, growing wild, by Horace Read. On his return journey he’s said to have pulled the emergency cord, jumped out, dug up the plant and quickly got back on the train. That was in the 1920s.

These days, one of the leading breeders is North American, Terra Nova Nurseries, the other British, RealFlor, with other breeders in North America, Britain and Holland also making improvements.

This year I grew almost all the recent Shasta daisy introductions. I can’t make definitive judgements in their first season, the plants went in at different times and varied in size enormously, but a few things are clear.

The range of flower forms is impressive with neat doubles and tightly anemone-centred forms and, while we still have no pink-flowered forms, the yellow-flowered varieties are becoming increasingly impressive.

As I write in early October, most still feature a few flowers except for 'Shapcott Gossamer' and 'Shapcott Ruffles' which have been over for many weeks, in spite of regular deadheading.

Both ‘Real Galaxy’ (above, in summer) and ‘Goldfinch’ are still opening new buds, as is ‘Victoria’s Secret’ but its stems are so thin that they’re collapsing under the weight of the flowers. ‘Lacrosse’ had a break but this morning I see that it's producing new buds. ‘Real Charmer’ has no buds coming but the open flowers still look good.

Next season will be a much better test as all will be starting from established plants. I’m looking forward to it, and all thanks to Luther Burbank and Horace Read.


Outstanding new perennial

Heliopsis Burning Hearts_G022907
 The outstanding new perennial I grew this year was in the garden only by chance. Heliopsis ‘Burning Hearts’ was a trade from Ian Hodgson, Editor-at-Large for the UK weekly magazine Garden News, and it’s been exceptional. I passed him some new heucheras, he gave me the heliopsis.

This hardy bronze-leaved perennial is a form of the North American native H. helianthoides var. scabra which grows in much of the east and south of the USA as well as in Canada. A number of things impressed me about ‘Burning Hearts’.

I planted three young plants, raised from seed Ian had sown earlier in the spring, in mid May. The purple-bronze foliage was impressive straight away, the plants grew away well and in June they were in flower. They’re still flowering today at about 90cm/3ft, in spite of being partially shaded by the unexpected vigour of a new physocarpus (not to mention some rampageous climbing beans).

The bright, slightly golden yellow petals are rolled back gently from the dark eye, each one stained red-orange at the base, and are perfectly shown off by those dark leaves although the red centres fades as the individual flowers age. The plants have been dead-headed regularly and a long succession of stems have been cut for fiery bouquets. They’ve been amazingly productive.

Jelitto Perennial Seeds, who developed ‘Burning Hearts’, point out this is like a supercharged version of ‘Summer Nights’ with darker leaves and flowers in more dramatically contrasting colours. They say it’s been in the works in Germany since 2004 when, the catalogue from Jelitto reveals, “the idea for ‘Burning Hearts’ came in a dream”. Hmmm…

Gardeners in both Britain and North America can order seed of H. helianthoides var. scabra 'Burning Hearts' from Jelitto Perennial Seeds.


Testing new varieties in my trial garden

Part of my new Northamptonshire trial garden.  Image ©GardenPhotos.com

Back in March, I started to create a trial garden, a test garden if you like, in Northamptonshire. The idea was to grow new, recent and upcoming varieties so I can report on them from experience as well as grow cut flowers and vegetables. And that’s exactly what I’ve been doing.

During winter, my friend and helper (and artist) Carol Parfitt made a start by digging out bindweed and just about everything else that was growing in the plot leaving me a clear canvas. Then I made a series of rectangular raised beds using 15cm (6in) pressure treated boards, each bed is 1.2m (4ft) wide with 60cm (2ft) paths between.

The soil is good: old English cottage garden soil that has been improved with soot and compost for generations (not to mention, in earlier days) enrichment from pigs and chickens. Most of the new beds had soil improver added.

Things were a little late getting going, after all I was making beds long after planting and sowing time for many varieties. But as soon as each bed was ready, plants and seeds went in. Then I’d make the next bed, and more plants went in.

Weeding has been a big issue, the tiniest slivers of bindweed root will grow, after all, and moving soil around exposed the seeds of annual weeds which soon germinated. But regular weeding has kept them down and only what Brits call the Duke of Argyll’s Tea Plant (Lycium barbarum) has proved a lasting problem. More about that another time.

The trials of leucanthemums and cosmos and clematis and calendula have been fascinating. Leucanthemum ‘Real Glory’ (below) has been a real star. We’ve had more cucumbers and tomatoes and zucchini than we could cope with (though not enough lettuces). Cut flowers have filled our tables and windowsills and been given away and there’ve been successes and failures amongst the American varieties I’ve been growing in Britain for the first time.

Through the autumn I’ll be discussing some of the results of this year’s trials here and also on my Plant Talk blog for Mr Fothergill’s. Please check back and take a look.

Leucanthemum 'Real 'Glory'. Image ©GardenPhotos.com


New ways with phlox

PhloxEarlibeautyZenithDaughterofPearl
The tall and colorful American native summer phlox, Phlox paniculata, has been popular for more than a hundred years. In 1917 five hundred and eighty four (yes, 584) different varieties were grown in the USA and in 1907 one Scottish nursery alone listed well over three hundred varieties. In Britain, the Royal Horticultural Society currently has a grand total of 577 in its database.

Most of these have now vanished, but there are a number of impressive breeding programmes, many using other species in addition to P. paniculata, going on in both North America and in Europe. Hans Hansen at Walters Gardens in Michigan, with his Opening Act and Fashionably Early series, and Charles Oliver at The Primrose Path in Pennsylvania, with his Earlibeauty Series (above), are leading the way along with Gosen Bartels in The Netherlands with his Flame Series.

But some of the best known varieties of the summer phlox have arisen in another way – they’ve been spotted in the wild or in abandoned gardens by plants people with a good eye, and an appreciation of something special.

I’ve mentioned these in my article about phlox in the current issue of The American Gardener but space was tight so I thought you’d be interested in a little more detail. These were all chosen for their freedom from mildew, but it’s important to remember that mildew resistance is not constant. I’ve seen ‘David’, and ‘David’s Lavender’, completely ruined by mildew.

‘Common Purple’ Found in 1982 by Marc Richardson and Richard Berry, founders of Goodness Grows Nursery, at an old abandoned homesite in Greene County, Georgia. The plant was in full bloom, with no sign of disease or problems. It was introduced by Goodness Grows in 1984.

PhloxSpeedLimit45‘David’ Selected at the Brandywine Conservancy, Chadds Ford, PAennsylvania by nurseryman Richard Simon and the Conservancy’s Horticulture Coordinator Mrs. F. M. Mooberry for its unusually large white flower heads and freedom from mildew. ‘David’s Lavender’ is a sport discovered in 2002 by Kathryn Litton at ItSaul Plants, Georgia.

‘Jeana’ Found in the 1990s by Jeana Prewitt of Nashville, Tennessee, growing mildew-free among "many thousands" of mildew-covered wild plants. Introduced in 2001 by the much missed Seneca Hill Perennials.

‘Speed Limit 45’ Spotted by Pierre Brunnerup, in the company of Allen Bush, by the sign on the roadside near Bush’s nursery in North Carolina and seen to be mildew free. Propagated by Bush and introduced in 2003.

These are exciting time for phlox enthusiasts, with so many new introductions. Those such as the Earlibeauty Series, with no P. paniculata in their background, seem best placed to remain mildew-resistant in the long term.

* Thank you to Charles Oliver and Allen Bush for the pictures.


Chocolate cosmos alive and well in Mexico, not extinct!

Chocolate cosmos growing in the wild in Mexico. © Universidad de Guadalajara

Since the chocolate cosmos, Cosmos atrosanguineus, began to be widely grown in the 1980s we’ve all assumed two things: that it was extinct the wild and that there was only one clone grown which never set any seed. Well, that’s what the Royal Botanic Gardens at Kew and others told us. They even participated in a plan to reintroduce it to the wild. It was all part of the mystique attached to this captivating chocolate-coloured and chocolate-scented plant.

Now, it turns out, Chocolate cosmos has been growing happily in Mexico all this time, and in a number of different locations. So it has no need of re-introduction. And, in New Zealand, chocolate cosmos has been grown from seed since 1990.

Mexican botanist Dr Aarón Rodríguez and his team found eleven relatively recent records of C. atrosanguineus, the earliest of which was from 1986, and the locations mentioned in the records led them out to find the plant in the wild. Dr Rodríguez told me: “The populations are quite numerous. Plants grow in mixed pine and oak forest.” They were found in three different Mexican counties.

From around the same time Dr Russell Poulter, a geneticist in New Zealand, has been raising plants from seed and working to ensure that the plants resembled the original wild form.

Dr Poulter’s work is the origin of the seed raised varieties now available, ‘Black Magic’ from Jelitto Perennial Seeds, and an unnamed form from Plant World Seeds. At least one more is on the way. His plants have also led to the introduction of new cuttings raised varieties including Dark Secret (‘3013/01’), Eclipse ('Hamcoec') and Spellbound (‘Hamcosp’).

It’s a little baffling that these two fundamental facts have slipped us by all these years. But it’s great news that this lovely plant remains established in the wild and that new introductions are being developed from seed-raised plants.

* Find out more in the June issue of the Royal Horticultural Society magazine The Plantsman, where I describe the horticultural history of the chocolate cosmos from its introduction to Britain in 1861 to the confirmation of its status in the wild and recent development of new cultivars, including those raised from seed. Please subscribe here.
.


The foxglove revival

Digitalis Goldcrest (left), Knee High Lavender and Foxlight Ruby Glow
Almost two hundred years ago Alexander Campbell, curator of the Manchester Botanical and Horticultural Society’s Garden, crossed a foxglove and a gloxinia (Digitalis grandiflora and Sinningia speciosa) to create what was known as Campbell’s hybrid foxglove.

It looks a little like a rusty D. grandiflora (below, right) but pollen from another foxglove - D. obscura, perhaps? - must have achieved the fertilisation that pollen from a gloxinia could never manage.

The first genuine foxglove hybrid between, D. purpurea and D. grandiflora, was made in 1849 but the seedlings were all sterile and it was not until 1924 that two hybrids that are still grown today were created at England’s John Innes Horticultural Institution: D. × mertonensis and D. ‘John Innes Tetra’.

Campbell's Hybrid Foxglove from 1825, said to be a cross with a gloxiniaSince then a large number of hybrids between different foxglove species have been created although, sadly, many have been lost including an interesting range created by the short lived Europa Nursery (anyone know where the owners, Tim Branney and Adam Draper, are now?).

Now, digitalis breeding is enjoying a bright revival with new hybrids being developed on both sides of the Atlantic. Goldcrest (‘Waldigone’) (above, left) was one of the first recent hybrids to make its mark. Three different breeding programmes in The Netherlands, in Suffolk (UK), and in Michigan, bring together the familiar British Native foxglove, D. purpurea, and D. canariensis from the Canary Islands. Foxlight Ruby Glow (‘Takforugl’) (above, right) is one of them. And, please, both parent plants are Digitalis. Let's not mess around with creating an imaginary new genus – Digiplexus.

Two new series of prolific dwarf hybrids are also just coming on to the market, the very short Knee High Series (‘Knee High Lavender’ above centre) from England and ‘Lucas’ and ‘Martina’ from The Netherlands.

I’ve recently published a long piece about the history of foxglove hybrids, from that early attempt using pollen from a gloxinia to the very latest developments. It appears in the current (March) issue of The Royal Horticultural Society magazine The Plantsman.

You can read my piece on foxglove hybrids online, but please take a moment to subscribe to The Plantsman: you can subscribe to The Plantsman here.


Seeds and plants by mail order: It’s not too late!

Cotwold Garden Flowers catalogue with too may plants tagged for ordering! ©GardenPhotos.com
Easy online ordering is a huge boon, but there’s nothing quite like scanning printed catalogs by a winter fire (or in the smallest room in the house) and tagging the tempting plants. And it's too late to order for the coming season.

And you can see from my post-its marking the must-have plants in England’s Cotswold Garden Flowers plant catalog just how many tempting plants there are!

Owner Bob Brown has a fine eye for a good plant, picking out the best of the old favorites, the best newcomers and landing his eye on undeservedly neglected species. Bob also breeds new crocosmias, kniphofias, aconitums, and other plants and his son Ed has some developed some intriguing new Sambucus (elder) varieties.

One of those tags marks a rare hardy (zone 6a) climbing tuberous perennial cucumber I remember from Kew decades ago and have always wanted to grow - Thladiantha dubia. No edible cucumbers unless you have male and female plants, I’m afraid, but well worth growing for its yellow flowers.

And one of Ed’s elders will definitely go on the order: ‘Gate Into Field’ (!) is described as: “A very vigorous elder hybrid, very large heads of pink-flushed deliciously scented flowers later than normal, July – September, dark pink flushed foliage with pale midribs.” OK, it grows to 5m… I’ll just have to knock down the shed to make space, I suppose. Order going in just before I post this – so you don’t grab the last of the plants I’m ordering before I do!

The Whole Seed Catalog for 2017 - with only the flowers tagged! Image ©GardenPhotos.comThe order to Missouri's Baker Creek Heirloom Seeds, who produce the extraordinary Whole Seed Catalog, has already arrived. The catalog is focused on its vast VAST array or heirloom edibles with a smaller section of flowers in the back. The tags only mark the flowers that appeal; I’d already taken out all the veg tags.

Have to say, this is the most astonishing catalog that I’ve ever seen. OK, it costs $9.95 (there’s a smaller free version). But there’s over 350 full color pages packed with goodies. Tomatoes, of course, feature strongly but there are also forty nine different lettuce varieties including the superb red leaved cut-and-come-again lettuce ‘Merlot’. I grew this last year and have ordered it again. It’s deep deep red in color, cuts for many weeks, tastes great and didn’t bolt. The three foot long Armenian melon from the 1400s is quite something, too.

I’ve also ordered the tall double America/African marigolds intended for cutting – never seen those before – and they also have some superb cut flower zinnias too.

Two oh-so-very-tempting catalogs. Here are the details.

Cotswold Garden Flowers
Order a fee printed catalog 
Order online
Plants can be sent to most of Europe but not North America

Baker Creek Heirloom Seeds
Order The Whole Seed Catalog
Order a fee printed catalog
Order online
Seed can be sent anywhere in the world but they make it clear that sending seed to Europe is expensive and difficult.


Transatlantic plant trials - any value?

Phlox and Sweet Pea Trials at the Royal Horticultural Society's garden at Wisley, near London. Image ©GardenPhotos.com
On both sides of the Atlantic, independent trials of perennials are organized by a number of different organizations. But I’ve sometimes seen the Royal Horticultural Society’s Award of Garden Merit (AGM), often given after trial (phlox and sweet pea trial, above), used in American catalogs and wondered how much relevance this British award has in North America. And does the Plant Evaluation Program run by the Chicago Botanic Garden and, in Delaware, the trials run by the Mount Cuba Center (baptisia trial, below) have any relevance in Britain?

Well, this year I’m chairing a group of experts working to update the list of AGM heucheras for the Royal Horticultural Society (RHS) and I’ve sent all the participants copies of the reports of the heuchera trials at both Mt. Cuba and the Chicago BG.

Of course, the climate in Delaware and in Illinois is, well, rather different from the climate in Britain but, for hardy perennials, if they grow in Delaware or Illinois, they’ll generally grow in Britain. And while modern American heuchera breeding is often focused on suitability for specific climates, the way the plants look when they’re growing well is relatively constant; a harmonious combination of flowers and foliage works well in any climate. So these reports will provide valuable background to our deliberations.

At first I was skeptical, but now I can understand why the AGM appears in American catalogs – it’s one of a number of useful factors that inform choice. The problem is that some gardeners in Texas or Maine, while they may see that the plants look wonderful, may not appreciate that the plants are given their award in a climate that’s closer to that of Oregon or Washington state may not do well for them. In fact they may die their first year.

But it’s not just climate, there’s another thing going on. I suspect that most British gardeners, seeing trial results from Delaware or Illinois, will just assume that they’re of no relevance, or even interest, and ignore them. True, disease resistance in American trials is unlikely to be of value elsewhere as different forms of the same disease are found in different places. But if the flowers are a dingy color in Chicago they’ll be dingy in Britain, too

American gardeners, on the other hand, seem to have a more open attitude and although they may not want to read the detailed reports of the RHS trials in which plants were given the AGM, they’re happy to accept that this is useful information and allow the awards to inform their plant choices as they decide what’s right for their own gardens.

And perhaps, as the dissemination of information about plants becomes more global, these reports help writers and advisors and consultants develop a deeper understanding of the plants so that the guidance we pass on is more informed. And they help nurseries decide what to grow. These trials and their reports are certainly invaluable to me. Even something as simple as paying attention to the factors these reports consider important is useful.

* The Mount Cuba Center is based near Wilmington, Delaware, just over an hour north of Washington DC, and its primary aim is to foster enthusiasm for native plants and their conservation. You can download their trials reports here.

* The Chicago Botanic Garden has been organizing trials of hardy perennials, and other plants, since 1985 under the expert guiding hand of Richard G. Hawke. You can download their trials reports here.

* The Royal Horticultural Society has been running trials of everything from hamamelis to cabbages to marigolds since, it seems, time began. You can search their database of trials here.
Baptisia trial at the Mount Cuba Center. Image ©Mount Cuba Center.