Transatlantic Plantsman

Britain's Favourite Perennial varieties

A few days ago I discussed Britain’s Favourite Perennials, the best selling individual genera as evidenced by sales at the Royal Horticultural Society’s Plant Centre at Wisley in Surrey. And I compared the current list with the Top Ten from three years ago. Today, let’s do the same for individual varieties.

So this is the current Top Ten of individual perennials sold at the Wisley Plant Centre. There are far more comings and goings in the last three years than there were with individual genera:

10 Lithodora diffusa ‘Heavenly Blue' – Up quite a few places from three years ago, it’s been around for ever.
9 Geranium Rozanne (‘Gerwat’) – Number six three years ago, this superb plant for ground cover or containers has been overtaken by both new and old favourites.
8 Primula vialii – The triumph of hope over experience! So enticing in flower in the plant centre but difficult to keep going from year to year so people just go back and buy it again.
7 Heuchera ‘Peach Flambé’ - A new colour in heucheras, these vibrant colours are supplanting those in darker shades.
6 Scabiosa ‘Pink Mist’ – Increased interest in attracting butterflies has surely helped this pretty plant enter the Top Ten.
5 Verbena bonariensis – Amazingly topped the chart three years ago, now slipped but still essential to so many gardeners. A white form would take the country by storm. Anyone ever seen one?
4 Erysimum ‘Bowles Mauve’ – Slipped from number three, but its very long flower season and good foliage still create demand. Technically a shrub but so often, strangely, classified as a perennial.
3 Gaura lindheimeri Cherry Brandy (‘Gauchebra’) – Like a much improved version of the old favourite ‘Siskiyou Pink’. Three years ago there were three gauras in the top twenty, now there’s just this one in the top twenty five.
2 Heuchera ‘Georgia Peach’ – Unique colouring, looks great in a pot on the sales bench and in a pot on the patio.
1 Scabiosa ‘Butterfly Blue’ – introduced as long ago as 1985, missing from the Top Ten (and the Top Twenty) three years ago – and now back on top. In 2000, 'Butterfly Blue' was also voted Perennial Plant of the Year in the United States.

On the other hand, dropped out of the Top Ten over the last three years are:
Imperata cylindrica ‘Rubra’, formerly Number Two, which has now vanished from the top twenty five;
Primula vulgaris, the British native primrose, formerly number four but still in the top twenty;
Erigeron karvinskianus, number five three years ago and not now even in the top twenty five;
Helleborus Ashwood Garden Hybrids has also vanished from the top twenty five;
Delphinium ‘Blue Butterfly’, also gone from the top twenty five;
Heuchera ‘Plum Puddin’’, also gone from the top twenty five;
Gaura lindheimeri has also gone from the top twenty five, but been replaced by a cultivar.

Thank you again to Malcolm Berry, Head of Buying at the RHS Plant Centres at Wisley in Surrey, Rosemoor in Devon, Harlow Carr in Yorkshire and Hyde Hall in Essex, for getting these fascinating figures together for me.

Britain's Favourite Perennials

When the British version of my Encyclopedia of Perennials came out two and a half years ago, I did some lectures entitled Britain’s Favourite Perennials featuring the Top Ten perennials in Britain.

But how did I decide which were the Top Ten, and in what order? Well, I asked the Head of Buying at the foremost plant centre in the country, at the Royal Horticultural Society’s garden at Wisley in Surrey, to tell me what his best sellers were in the previous year – that seemed a pretty good guide.

Well, I’ll again be lecturing on the same subject later this year so I asked him to give me his most recent figures and today I’ll let you into the secret. First with the best selling genera, and next time with the best selling individual varieties. So here goes. American readers will notice which two plants are not in the Top Ten:
10 New at Number Ten – Dianthus. Not even in the Top Twenty three years ago, and with no individual varieties in the top twenty five, I suspect that the recent flood of prolific dwarf types from Whetman Pinks accounts for this increase in popularity.
9 Same position as last year – Echinacea. The appeal of all the new colours and flower forms is balanced by the fact that many are proving more difficult to get through the winter than we’d like.
8 Down one place – Penstemon. Slipping from seventh to eighth place, but with a pretty small drop in actual sales, penstemon remain popular for their long season of dependable colour.
7 In from nowhere – Salvia. Mysteriously absent from even the Top Twenty last time, this is a case where enthusiastic articles in The Garden, the members’ magazine for the RHS, may have encouraged demand.
6 Down from Number Three this year – Euphorbia. I suspect that this drop may be the result of heavy promotion of new variegated varieties not being matched by their quality and longevity in the garden.
5 Same as last year – Iris. The vast variety of types allows changes in trends to be picked up by one kind of iris as another becomes less fashionable.
4 Roaring up the charts – Agapanthus. Our changing climate (allowing gardeners in more parts of the country to grow more varieties), the increasing popularity of growing perennials in containers and some very active specialist nurseries all helped boost enthusiasm for agapanthus.
3 Down one place – Helleborus. A small drop in sales numbers, but it’s more the huge rise in sales of the new Number Two plant the pushes them lower.
2 Almost 40% up in sales – Heuchera. Placed fourth three years ago, the continuing stream of good new varieties, with two in the top ten of individual best sellers, solidifies enthusiasm for these superb foliage and flowering plants.

1 And still at Number One of the best selling perennials, but only just – Geranium. The lead has shrunk so much that Geranium is now only 0.22% ahead of Heuchera while three years ago it as 13% ahead of Helleborus. But their versatility, easygoing nature, and the introduction of good new varieties keep them at the top.

And that's right, North American readers - no Hosta and no Hemerocallis.

Next time I’ll look at the best selling individual perennial varieties… There’s some surprises there to.

Thank you to Malcolm Berry, Head of Buying at the RHS Plant Centres at Wisley in Surrey, Rosemoor in Devon, Harlow Carr in Yorkshire and Hyde Hall in Essex, for getting these fascinating figures together for me.

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.

Deer resistant – guaranteed!

There’s a little native shrub growing in our damp woods that never, EVER, gets eaten by the deer. Just in case you’ve missed me bashing on about it in the past, the white-tailed deer are a menace here in north east Pennsylvania, eating wildflowers and native tree seedlings with equal enthusiasm. But Kalmia angustifolia, sheep laurel, is never eaten.

This little relative of the well-known mountain laurel, Kalmia latifolia, the state flower of Pennsylvania, only grows about 38cm/15in in these parts but can apparently reach 90cm/3ft or even 1.8m/6ft. Its pretty clusters of flowers are grouped all round the stem but are only about 12mm/0.5in across. It runs gently at the root to make wide, open stands of rather sparse evergreen ground cover under our oaks and maples.

It’s a shame it’s not a little more colourful. But not only are the flowers small, but they open under tufts of new foliage so that as you look down on the low-growing plants the flower clusters tend to be hidden. There are half a dozen named forms, in various colors, listed on the University of Connecticut website (scroll down) but they’d have to be a lot better than the wild form to tempt me.

Often cited as poisonous to sheep and cattle – hence one of its other common names, lambkill – it is not, apparently, actually poisonous to deer but they seem to leave it along anyway. They eat the mountain laurel, K. latifolia, which is regularly browsed to about 1.5m/5ft, and almost everything else.

What we need, perhaps, are hybrids between deer-resistant K. angustifolia and deer-favourite K. latifolia to give us flamboyant shrubs the deer won’t eat. If only it were that simple. Such hybrids  have, in fact, been created when pollen from K. latifolia was used to pollinate K. angustifolia and 2000 seedlings germinated from almost 10,000 seeds. Almost all the seedlings were weak and died. If the white form of K. angustifolia was used then more seedlings survived but their main ornamental feature was the bright yellow young growth.

Well… perhaps I should try to get hold some of those taller forms… or perhaps in the garden with better soil and few doses of liquid fertilizer iwild plants will make more impressivespecimens. But, out in the woods, at least it’s a pretty plant to break up the dominance of the two ferns the deer don’t eat – the hay-scented fern, Dennstaedtia punctilobula, and New York fern, Thelypteris noveboracensis.

Fore more on Kalmia angustifolia, sheep laurel, and creating hybrids see Kalmia: Mountain Laurel and Related Species by Richard A. Jaynes.

Shameless orchidaceous nepotism!

My wife’s new book has just been announced. It’s called Bloom-Again Orchids: Tips and Tricks for Glorious Displays Year After Year by judywhite. The title says it all, really. And it's great!

People think orchids are difficult to grow and of course some are. But this book is about orchids which anyone can grow and which are readily available across America and across Britain in nurseries, garden centers and even chain stores and markets. They’re easy to find, and easy to grow. And of course they look fabulous.

So if they’re so easy why do we need a book about them? Well, it’s just like plants in the garden – hostas like shade and echinaceas like sun and they won’t thrive unless we give them what they need. Same with orchids, give them the light and the temperatures they need – no problem.

In a lively accessible style, this book explains their features, explains what they like, and gives a glimpse into their background. I looked it over as a work-in-progress, I can assure you it’s a great read. What's more, judy’s stunning pictures will make you want to grow every single one. And of course you can – with a little help from this book.

You’re probably familiar judy’s earlier orchid book, the multi-award winning Taylor’s Guide to Orchids. Be sure to take a look her new book.

Bloom-Again Orchids will be published in the fall. You can pre-order Bloom-Again Orchids in North America here, and in Britain here.

And check out judy's recent blog post about South African Disa orchids over on the new Timber Press blog.

That OK dear? You don’t think I’ve overdone it?

(Actually, it’s a really good book!)

Ornamental rhubarbs - send your pictures to the RHS

The ornamental rhubarbs, Rheum, are dramatic flowering and foliage plants making bold specimens with, at their best, a very long season of interest. They're related to the culinary rhubarb, of course, but look better! You can help the Herbaceous Plant Committee of Royal Horticultural Society with our research on these plants.

After the trial of ornamental rhubarbs held at the RHS garden at Wisley, just outside London, ended in 2006 the plants were moved for further assessment and we took a look at them a few days ago. Frankly, they're a bit of a muddle. It's not as if there's a huge number of them, but the problem is that they've become so mixed up that when you buy a plant under a familiar or promising name you've little idea of what you're actually going to get. It was clear that many of the plants we assessed were wrongly named and some good plants were not represented.

These plants have five good features: the unfolding spring foliage can be very colourful, often dark red; the mature leaves can be impressive too, especially if they retain their red colouring on the upper surface and have an attractive shape; the flowering heads can be bold and colourful; the seed heads can also be impressive; and the whole plant can make a fine and imposing specimen.

So we'd like you to send us pictures of really good ornamental rhubarbs. If you have plants which are especially impressive in one, some or all of these ways - please send me a picture. Tell me the plant's name, where you got it and when you got it and it will help the Herbaceous Plant Committee of the RHS understand the range of plants which are actually being grown around the country - and under what names. Please don't send plants! Just email pictures.

Thank you! I'll report back here as we continue the research.

 

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.

Glorious buttercups

One of the last and most dramatic sights before flying back to Pennsylvania this week was this cast field of buttercups alongside the River Nene in Northamptonshire. I’ve been passing this field for many years and they’ve never looked so spectacular. Many acres of them fill the meadows and the golden pollen covers your legs as you walk through.

This is the Meadow Buttercup, Ranunculus acris, and there’s a British children’s game, which I remember but which is largely now forgotten. You pick a flower and hold it under the child’s chin; if the yellow colour is reflected on the skin it means the child likes butter.

Found in every county in Britain and Ireland, and now established in almost every state and province of North America, the herbalist Nicholas Culpepper (1616–1654) remarked: “They grow common everywhere. Unless you run your Head into a Hedge, you cannot but see them as you walk.”

Unexpectedly perhaps, the Meadow Buttercup is unpalatable to grazing animals – it’s toxic, but also causes soreness of the mouth so it’s rare for much to be eaten - and in many meadows has been eradicated with weed killers to “improve” the quality of the grazing. In hay meadows, however, buttercups are not a problem as the toxic effect disappears as the cut plants dry out.

In Northamptonshire, not far from where these pictures were taken, Meadow Buttercup is still known as Crowpeckle and other local names around the country include Goldweed, Soldier Buttons, Butter and Cheese, Crazy Bet, and Teacups. Crowfoot, referring to the shape of the leaves, was the most common name until Buttercup became widely used in the eighteenth century.

Needless to say, when so many thousands grow together unusual forms have been selected and named: ‘Citrinus’ (pale yellow) ‘Flore Pleno’ (green-centred, tightly double flowers), ‘Stevenii’ (unusually tall and vigorous), ‘Sulphurea’ (pale yellow with dark yellow stamens) plus two variegated forms: Cricket’ (streaked and mottled in yellow-green, brightest in winter) and ‘Jaffa’ (more variegation, so the effect is brighter).

‘Flore Pleno’ in particular is good in the garden, though in rich soil it can grow too tall the stems may be unable to support the weight of the double flowers.

Thanks to Carol Parfitt for the picture and to Bob for posing on the path.

Chelsea postscript - Spotty Dotty correction

Egg on face time, folks! Well, there's a lesson. It turns out that this is 'Kaleidoscope' and not 'Spotty Dotty'! The info in my piece came from someone putting the exhibit together and the excitement of the occasion scrambled either my note-taking or their explanation. I apologise. I dare say we were both knackered.

And  the superb specimen on display was in fact provided by Piers Bowley of Bowley Plants. Happy to make the correction, thanks to the designer of the exhibit Sue Ward for highlighgting the mistake in her comment to the original post.

I have to say that 'Kaleidoscope' is an appropriate name for the pattern on the foliage; the plant of 'Spotty Dotty' I grew did not thrive and faded away - apparently without developing foliage in its true character.

And what about that patent? The 'Spotty Dotty' patent text could well describe what I saw on the day. But look at the 'Kaleidoscope' patent and the description is more appropriate: "Beautiful large umbrella shaped leaves with a kaleidoscope look of color and pattern."

So mistake corrected. Bit of a blunder though, there are only two of these new hybrids and I got them confused! Sigh...

Yes, the specimen of Podophyllum ‘Spotty Dotty’ on the Gold Medal winning Chelsea Flower Show exhibit from the Hardy Plant Society was just superb; VP is right in her recent comment. Grown for the Hardy Plant Society exhibit by Kevin Hughes, ‘Spotty Dotty’ was created by Janet Egger at Terra Nova Nurseries in Portland Oregon. This plant has been patented, it’s interesting to quote some details of the patent.

“This new cultivar originated from a cross between Podophyllum hybrid ‘374’ (an unpatented proprietary plant) as the seed parent and Podophyllum delavayi ‘64’ (an unpatented proprietary plant) as the pollen parent. The seed parent, Podophyllum hybrid ‘374’, is an outstanding selection out of a hybrid swarm from a Japanese nursery, which is believed to have come from P. difforme, P. delavayi , and P. versipelle. The pollen parent, Podophyllum delavayi ‘64’ is a highly colored selection. The new cultivar was chosen for its outstanding foliage and vigor.

“This plant is characterized by the following:
1. Beautiful large umbrella shaped, lobed leaves with an attractive brown spotted spring color followed by green leaves with lighter spots.
2. Two leaves per crown that will increase in size with maturity to 40 cm. or more wide.
3. Numerous large red maroon flowers with maturity.
4. A rhizomatous habit.
5. Excellent vigor.”

I would only quarrel with point 5: my plant did not prove to be at all vigorous.

Smaller, less impressive plants were to be seen on other Chelsea Flower Show displays. The plant in its terracotta pot on the Hardy Plant Society exhibit was by far the most impressive. It just showed whata magnificent plant this can be when grown well.

Thanks VP for the reminder of what a great specimen was on show and what a great garden specimen Podophyllum ‘Spotty Dotty’ can be.

Chelsea - the party's over

Well Chelsea’s over, we’re all knackered  - exhibitors, visitors and press alike – and there were some great gardens, some great plants and some great silliness. I posted thirty four pieces for the Royal Horticultural Society's New Plants coverage, nine pieces here starting with this one, did a guest rant over on Garden Rant and was interviewed by BBC radio.

Main awards? The Daily Telegraph Garden won the top award for a show garden, fair enough. The dahlia exhibit (in May!) from Winchester Growers won top floral exhibit although Jekka McVicar’s herbs must have pushed it close. There was another silly manufactured “gnomes at Chelsea” outrage and the designer of the Plasticine garden was rewarded not with a medal (well, he did get a Plasticine one) but a “Special Letter” from the RHS.

The Queen visited, Rod Stewart visited, several bikini-clad models with snorkels were seen as well – unfortunately not at the same place at the same time. The twice daily BBC TV coverage was again condemned as ignoring plants and including far too much irrelevant twaddle. (“twaddle” - an old fashioned English colloquialism meaning nonsense or irrelevance.) Pretty much as usual.

 And in the Great Pavilion the overall standard was superb and although there were fewer large show gardens this year as a number of sponsors had pulled out – well, it didn’t really matter as the quality of smaller show gardens was so good. Top plant? Well, this amazing Puya chinensis on the Burncoose Nurseries display was pretty smart.