Shrubs

Lesson in witch hazels

HamamelisMollisPlusRootstockI’m sure that at about this time of year, you’ve come to expect an enthusiastic post about American native witch hazel. There was one back in 2007, and also one in 2009. There’ve been more. Well this year – not quite. American native witch hazel – yes. But with a twist.

The picture shows our rapidly growing Hamamelis x intermedia ‘Pallida’; its has large, bright yellow spidery spring flowers. Here, on its spreading branches, you see its fall color on the wane and turning biscuit brown before it finally drops off. But, in the middle, on a very vigorous and absolutely vertical shoot which is only a couple of years old, are some bright yellow leaves.

That bright yellow foliage does not belong to H. x intermedia ‘Pallida’. It’s foliage on growth which has shot up from the rootstock on to which is ‘Pallida’ is grafted. A scattering of small flowers opened not so long ago to confirm that the vertical growth is a shoot of H. virginiana - the American native witch hazel, H. virginiana - on to which varieties of the spring flowering Asian witch hazels are grafted.

So not only is this ‘Pallida’ an impostor without its trade mark strong scent, as I remarked last year, but its rootstock is threatening a takeover.

Where are those pruners?


So, it's January already

Euonymus alatus, snow, October. Image ©GardenPhotos.com (all rights reserved)
Back in Pennsylvania after a visit back to Britain and what happens - it snows, on 29 October. With up to 10in/25cm forecast before it eases off during the night. But it certainly makes Euonymus alatus, in its brilliant red fall color, look even more impressive than usual.

This shrub is much admired, but also much disparaged, here in the US as although its fall color is spectacular it can be invasive. You know what's coming next, a slightly cynical remark about the almost universal panic about invasiveness when any non-native plant throws a few self sown seedlings. Well, in some areas it can certainly be a problem. But we've been here for over ten years, and seedlings from these plants have popped up all over the place. But none has grown to more than a few inches - because the deer eat them.

In some cases, like Japanese barberry (Berberis thunbergii), invasive plants take hold because the deer eat all the native competition. In this, it seems, the deer are doing us a favor.

UPDATE Just after I posted this we lost power. The weight of snow on the many trees still in leaf brought them crashing on to the power lines. So we built a fire, and we emptied the fridge and put the contents outside the front door where it was below feezing. We had about 12in/30cm of snow in all and the power came back a few hours ago - about 28 hours later. We intended to deliver the next book to the publisher first thing Monday morning. Sorry... no power = no computers... Late Sunday night and we're still getting it ready. It would have been different in the days of slides and typewriters.


Foliage for cutting and for the garden

Physocarpus Coppertina in spring (with irises) and in fall. Images ©GardenPhotos.com)
Those of you who’ve been following this blog for a while will be aware that I’m a big fan of Physocarpus – ninebark as it’s known in North America – and especially of the variety Coppertina (‘Diable d’Or’). And it turns out that I’m not the only one. The Association of Specialty Cut Flower Growers has named Physocarpus Coppertina as one of its three Cut Flowers of the Year.

As soon as I heard this judy went out and cut eight or nine stems from the plant outside my window. OK, we let a few of the stems get dry when the water in the vase got low and we forgot to top it up. But even those stems lasted almost two weeks before they started to look sad – with no special treatment and no flower food. And those whose stems never got dry lasted almost three weeks and even then it wasn’t as if they were dead… just not really looking lively any more. They were in fairly good light and the only change was that they steadily became less bronze and more green. Later, I tried a couple of stems in very poor light – but they didn’t really like it.

Physocarpus Coppertina is a tough and resilient shrub which after a year or two in the garden produces so much growth that cutting shoots for the house won’t make it look thin. In the fall, after a shower, its bronze foliage gleamed beautifully and with Hosta ‘Christmas Tree’ at the base it makes a lovely picture.

But our Coppertina plants have never bloomed or fruited well. They’re in good light all the time but not in full sun for more than a few hours a day – perhaps it’s not enough. But, frankly, it doesn’t really matter. With their amber new shoots maturing to rich bronze and with its proven value when cut for the house, it’s one of the first shrubs I’d choose for a new garden.

The other winners of the Association of Specialty Cut Flower Growers Cut Flowers of the Year award are:
•    Fresh cut flower: Lisianthus 'Mariachi Carmine'
•    Dried flower: Capiscum 'Nippon Taka'

But you know… I really don’t find them so very interesting.


Surprising plants succeed in dry shade

Hydrangea in Dry Shade. Image ©GardenPhotos.com (all rigts reserved)
I have a piece about growing plants in dry shade in Britain's Independent newspaper today and there's also a version in its sparky little sister paper i.

But as well as the plants I mention in the piece - and the many I discuss in my new book Planting the Dry Shade Garden - a couple of slightly unexpected plants have been doing surprisingly well in dry shade this year.

The first is Hydrangea arborescens 'White Dome', you can see it in the picture (click to enlarge). Only one nursery seems to stock it in Britain, though it's much more widely available in North America, but its broad white lacecap flowerheads set against rich green leaves are lovely and well supported by slender but strong stems. What's more, the skeletons of those same flowers don't fall to pieces in the autumn but remain through the winter for a lovely second season effect.

The other surprising dry shade success has been the yellow-leaved creeping Jenny, Lysimachia nummularia 'Aurea' (on the right, at the front in the picture). This shows the benefit of a little soil improvement, its shallow roots taking moisture from just the top few inches of soil. It looked a little sad when it got really parched but soon colored up when a little of our recent thunderstorms penetrated the tree canopy.


For more on dry shade…
Read my piece in The Independent
Subscribe to The Independent's lively little sister i
Find out more about the book on its own British website
Find out more about the book on its own North American website
Order the book in Britain
Order the book in North America
Check out the book's Facebook page


Variegated ceanothus - old and new

Ceanothus 'Zanzibar', the first of the variegated varieties. Image ©GardenPhotos.com (all righjs reserved)
With more variegated ceanothus appearing, we now seem have about eight, this seems a good moment to take a look. Any evergreen shrub that features variegated foliage to spark interest in all those months when there are no flowers is well worth having. With ceanothus the flowers and the foliage look good together too.

The first variegated ceanothus I grew, back in the 1990s, and the first to appear was 'Zanzibar' (above, click to enlarge), less often but more correctly known as 'Pershore Zanzibar'. It's still the most often seen in Britain, its broad leaves each with a central dark green stripe and wide lemon-lime edge. It's a sport of the old favorite 'A. T. Johnson'.

This is an upright and bushy plant and from a distance the effect is of a pale yellow cloud, so it makes a good back-of-the-border feature. Then in spring the clusters of pale blue flowers are shown off beautifully. The foliage can be little sparse in early spring, as it tends to lose its oldest leaves in the winter, but new growth soon makes up the deficiency. El Dorado ('Perado'), found as a sport on 'Pershore Zanzibar', is similar, but less bright and with a broader green stripe, and some say its softer coloring helps it integrate with other plants more effectively.

The next I grew - I have a feeling it was sent to me in England by the Seattle plant nut Bob Lilly also in the 1990s - was 'Diamond Heights', one of two variegated forms of the spreading C. griseus. Lurking in the back of my memory is the notion that this was found amongst an extensive planting along a road in the district of San Francisco of that name. With a much lower, more spreading and mounding habit of growth, its deep green center and broad limey yellow edge, and its pale blue flowers in late spring and early summer  - 'Diamond Heights' is ideal trailing over a sunny stone retaining wall.

More recently we’ve had a rather different variegated form of C. griseus, 'Silver Surprise', a sport of 'Yankee Point', which is more upright and bushy than 'Diamond Heights', but less big and bold than 'Pershore Zanzibar', and with the edges of the dark green leaves marked in silvery white. The blue flowers appear in Ceanothus 'Lemon and Lime', the latest variegated form. Image ©GardenPhotos.com (all rights reserved) late spring.

Now, recently introduced, from England, and with longer, more slender foliage ' Lemon and Lime' (left, click to enlarge) is a variegated version of the old favorite 'Cynthia Postan' and has a more airy and refined look than 'Pershore Zanzibar'.

There are more… 'Golden Elan', with pink flowers; 'Bright Eyes', said to be similar to 'Diamond Heights'; 'Blue and Gold', which is said to revert to green. But these I've never seen.

The problem, of course, is that with their progenitors originating in California they're not as hardy as we'd like. Can't grow them here in north east Pennsylvania. Planting against a west or south wall is a big help for the more upright ones, as is good drainage and knocking off any winter snow accumulation.

All we need now is a variegated form of the black-leaved Ceanothus 'Tuxedo'. Wow!


Buddleias with a colorful difference

Buddleia,Buddleja,Masquerade,Variegata,Santana. Image ©GardenPhotos.com 
In the second piece about variegated plants... Looking at our Buddleja 'Pink Delight' surging upwards as it responds to some fairly brutal spring pruning, I began to wonder why we hadn't planted a variegated variety.

Next time I think we should, see how it does here in zone 5 at the edge of the buddleja's hardiness range. And, I might add, where in the more than ten years I've never seen a buddleia seedling – so although buddleias may be invasive in some parts of the country, not here. Anyway… variegated varieties of many plants are often thought to be less hardy. It would be worth a try.

There are five variegated buddleias and, oddly, three are derived from the popular green-leaved 'Royal Red'.

'Variegata' is the one that will instantly appeal to most gardeners looking for a variegated buddleia, just because of the name. Forget it. OK, it's fairly attractive, its creamy yellow edged leaves set off the reddish purple flowers very effectively. It’s just that it's notorious for throwing plain green unvariegated shoots which quickly take over. More trouble than it's worth.

'Harlequin' is similar to 'Variegata' but less inclined to throw unvariegated shoots while 'Santana', the third of the 'Royal Red' derivatives, is the most stable of the three and also boasts the largest leaves so the variegation is the most dramatic. These all feature reddish purple flowers although the precise shades may be slightly different.

Then there's Masquerade ('Notbud'), raised by the good people at Britain's East Malling Research Centre, where the English Butterfly Series was also developed. To be concise, this is basically an even more stable form of 'Harlequin' and is probably the pick of them all. Unless you fancy white flowers with your variegation in which case try the rarely seen 'White Harlequin' although this is right up there with 'Variegata' for throwing plain green growth.

I have to say that I really like the Masquerade ('Notbud') combination of the reddish purple flowers set against the yellow edged leaves – it's a whole planting partnership in just one plant.


Brits don't grow New York's top roses

Rosa, rose, Brothers Grimm Fairy Tale, Korassenet, NYBG, Kordes. Image ©Kordes. Once I've looked through each issue of The American Gardener, the excellent member magazine from the American Horticultural Society, it goes - let's be honest - into the bathroom. Where it's perused again, now and then, before finally going on the shelf.

The other day I was looking through the March/April edition when I came again on the list of the top-rated roses at the Peggy Rockefeller Rose Garden at the New York Botanical Garden (NYBG). Frankly, many of them I didn't know. Then I wondered: how many of these are well rated in Britain?

So I started to look them up. Top of the NYBG list is Brother's Grimm Fairy Tale (right, click to enlarge). It's not listed at all by the Royal Horticultural Society in Britain, a Google search turns up almost nothing. First thing – that rogue apostrophe. Its correct name does not have that apostrophe.

Turns out it has five, yes, five other names. All but one are selling names used in various countries – Brothers Grimm Fairy Tale is also sold as Eternal Flame (in Britain), Joli Tambour, Gremlin, and it was first sold in the USA as Gebrüder Grimm. And the one thing that ties them all together is the correct cultivar name, which is 'Korassenet'.

In roses, the cultivar name, in this case 'Korassenet', is often more like an originator's code name and in those cases the rose is never sold solely under that name. You may have noticed them all in my recent review of David Austin's new rose book.

Rosa,rose,Caramel Fairy Tale,'Korkinteral', NYBG, Kordes. Image ©Kordes. But the international naming rules that govern these things state that the cultivar name must always be given with whatever selling name is being used, so no one ends up buying the same rose under two different names. Bad for the home gardener, but a disaster for a nursery which might buy 500 of each. Unfortunately, The American Gardener list did not include the cultivar name, neither does the NYBG's own list.

So… Once I'd discovered its true cultivar name, via the invaluable Help Me Find Roses website, I was able to look it up in Britain and found that there's only one British supplier and it has no awards. Not very encouraging.

I did the same with the rest of the top five. Next on the NYBG list was Caramel Fairy Tale ('Korkinteral') Rosa,rose,Cinderella Fairy Tale,'Korfolbalt',Kordes. Image ©Kordes. (left, click to enlarge), also known as Caramella and Reminiscence - no British suppliers. Third on the list was Cinderella Fairy Tale ('Korfolbalt') (right, click to enlarge), also known as Cinderella and La Giralda - no British suppliers. Fourth came 'Ducher', from way back in 1869 when muddling about with names was never even considered – no British suppliers. And fifth came Easter Basket ('Meiopoten') – no British suppliers.

So, not only did the five top roses at the Peggy Rockefeller Rose Garden at the NYBG not have any awards or recommendations but only one was actually on sale in Britain – and from just one nursery.

And the research would have been far simpler if the names had been given as the international rules say they should be.


Our local Mountain Laurel

Kalmia,Mountain Laurel,Jaynes,40026. Image ©GardenPhotos.com
All over the woods here in north east Pennsylvania the flowering of the Mountain Laurel (Kalmia latifolia) is at its peak. And it's intriguing to see how much the flower color varies in these lovely evergreen rhododendron relatives.

The three in the picture (click to enlarge) are all from wild in the woods no more than about 100ft/30m from our front door. Farther away there are darker pinks, almost red, and I noticed 15 miles away last night that great drifts of them were all noticeably dark.

This variation in wild plants has been enhanced by plant breeders, as can be seen in the pictures of the kalmias stocked by Rare Find Nursery and in the only book on this invaluable acid-loving shrubs – Kalmia: Mountain Laurel and Related Species by Richard A. Jaynes (Timber Press). Sadly, that book is now out of print but you can find it used at you-know-where for about $30 and new at up to almost $300! (£20 used or £25 from their British site.)

The only problem is deer - all those in the woods here are stripped bare to about 5ft/1.5m and those now inside our deer fence are slow to recover. We need deer candy Kalmia latifolia crossed with the short and suckering, 100% deer resistant Kalmia angustifolia. I discussed this idea a couple of years ago. We live in hope.


            


English Roses revealed

 

English Roses,David Austin,book, A couple of days ago I sat down to take a close look at the new edition of The English Roses by David Austin (Conran Octopus). This is a beautiful rose-by-rose account of the many many roses – new roses in the old style - created bythe British rose breeder David Austin and popular all over the world.

The original version of this book appeared in 1993, but the heart of this revised edition remains the same: studio portraits of individual English Roses, shot against a white background, are accompanied by short texts describing each rose and its virtues. The Clay Perry pictures from the old version have been replaced by beautiful portraits by Howard Rice.

The extensive introductory material is fascinating and the account of the origins of these indispensible roses reveals some interesting balancing of good qualities and less favorable ones in choosing new introductions. Over fifty varieties for which less favorable qualities have proved too dominating are reduced to short unillustrated entries at the end.

One double-edged change, compared with my 1993 edition, is that the roses are grouped according to their origins and general qualities instead of alphabetically. This helps us understand their connections with each other, and with the heritage and modern roses from which they're derived. But, of course, most of us looking up a particular rose will now have to go via the index.

I was very pleased to see that he points out the inevitable faults of some roses, like lack of fragrance, as The Wedgwood Rose,David Austin,English Rose,Ausjosiah. Image ©David Austin Roses. well as good qualities, and also mentions the impressive disease-resistance of some like Rosemoor ('Austough') -  "almost completely free of disease", The Mayflower ('Austilly')  - "completely free of disease" and The Wedgwood Rose ('Ausjosiah') - "virtually disease free" (right, click to enlarge). It was also good to see so many of his bush roses recommended as climbers; I've grown Heritage ('Ausblush') as a climber for many years and it's spectacular.

But this is not a book about growing English Roses – cultural advice takes up just four pages – so American readers will be disappointed that there's no advice on choosing and growing English Roses in North America. Perhaps we need a separate book: English Roses for American Gardens.

One odd thing: as it happened, the day I was looking over this book, our friend who looks after our garden in England emailed to report how well the rose she'd moved in the winter was doing, a dwarf and fragrant David Austin rose called 'Pretty Jessica'. I looked it up the book - but it's not there. I hunted, but I couldn't find it.

So I checked in my 1993 edition, and there it is – where its popularity, clear pink color, fragrance and its susceptibility to disease is noted. But it's vanished from the new edition – although it's still for sale on the website.

This is a beautiful book, with lovely photography and full of good information. It's a book in which it's a pleasure to learn more about the most important roses of recent times.

Book Bullets

  • There's plenty of space for much more information on each rose, why not use it?
  • How about lists of the most fragrant, the best for small gardens, the longest flowering etc?
  • How about some specific growing advice for American readers?
  • A few pages seem to be printed in bold type.
  • Where is 'Pretty Jessica'?!

               


Kolkwitzia Dreamcatcher finally flowers!

Kolkwitzia,Dreamcatcher,foliage,flower,Maradco. ©GardenPhotos.com (all rights reserved)
Ever since we received plants on trial from the shrub breeder and grower Spring Meadow Nursery (no retail sales), we've loved Kolkwitzia amabilis Dreamcatcher ('Maradco'). It's one of the best foliage shrubs I've ever grown. I wrote it up here in June last year, and mentioned that I was surprised that it never flowers. Now it has.

Perhaps it enjoyed last summer, perhaps it was the extra doses of lime. But the tips of many of the shoots on the slightly older plant, the one in more sun, are carrying reddish pink buds opening to almost white flowers. When I wrote about this plant last time I was cautious about the effect of the pink flowers against the yellow foliage – it actually looks pretty good.

So I thought I'd show it to you.

Images ©GardenPhotos.com