Previous month:
April 2014
Next month:
June 2014

May 2014

Chelsea Flower Show Plant Of The Year 2014

Chelsea Plant Of The Year winner and runners up 2014. Images ©RHS except the tomato ©Tiffany Woods/Oregon State University
There are plenty of trade shows around the world where awards are given for new plants. But the Chelsea Plant Of The Year is one of the few awards made to new plants as they’re launched to gardeners. The 2014 award, the fifth, was made last week at London’s prestigious Chelsea Flower Show and the winner was a double flowered, bicolored variety of mophead/Hortensia hydrangea - Hydrangea macrophylla called Miss Saori (‘H20-2’) - which is not only an eye-catchingly attractive hardy garden shrub but which has already had success as a cut flower.

This year’s runner up was the unique black and white tall bearded iris ‘Domino Noir’, raised in France, and in third place was the Dutch, long flowering, hardiest yet Gerbera 'Garvinia Sweet Glow' with vibrant orange flowers.

Highlights amongst the rather long shortlist of twenty plants were the first double-flowered black petunia, ‘Black Knight’, the antioxidant-rich purple tomato ‘Indigo Rose’, the largest flowered Alstroemeria yet seen Inca Smile (‘Koncasmile’) and the lovely golden leaved Eryngium ‘Neptune’s Gold. All are illustrated above (click to enlarge) and should become available to gardeners soon.

Chelsea Plant Of The Year winners 2010-2013. Images ©RHS.As for previous winners, so far the track record and the international availability have been mixed. Previous winners were (left, click to enlarge):
Streptocarpus ‘Harlequin Blue’ (2010): Beautiful, compact and with a long season but as a house plant it has limited appeal. Not yet available in North America.
Anemone ‘Wild Swan’ (2011): A lovely white flowered variety with blue backs to the petals but, as the plant buyer for a major UK mail order nursery told me: “We had huge problems with it – we received poor quality plants and there were long delays. My understanding is that there are still problems, so we won't be listing it in the near future”. Available on both sides of the Atlantic.
Digitalis Illumination Pink (‘Tmdgfp001’) (2102): A spectacular breeding breakthrough with dramatic, colourful, bee-friendly flower spikes and now widely available on both sides of the Atlantic but less hardy than first claimed.
Mahonia ‘Soft Caress’: The first winner to be developed in the US, and an excellent evergreen shrub without the spines that so many mahonias have and which many people find annoying. Available on both sides of the Atlantic.

You can find a full list of this year’s shortlisted plants on the RHS website.

All Images ©RHS except Tomato 'Indigo Rose'  ©Tiffany Woods/Oregon State University.

Rampageous wisteria in the Pennslyvania woods

Wisteria floribunda smothering the Pennsylvania woods. Image ©GardenPhotos.comInvasive plants keep turning up on these pages, and often I’m less than supportive of the way the plant police want to rip out any non-native plants that turn up in wild places – as with the snowdrops I wrote about last month - whether or not they’re doing any harm.

Well, here’s one that we can justifiably worry about.

I spotted the bluish purple flowers hanging from the branches as I drove between the woods and the Delaware River in Pennsylvania the other day. That's Wisteria, I thought. I was on a tight schedule and couldn't stop, so when I got home I checked with the Pennsylvania Flora Project website which told me that no wisterias, native or introduced, grow in the area. The USDA plants website said the same thing.

Yesterday I was again passing that way and took a closer look. Yes, it’s wisteria – but the Japanese Wisteria floribunda (below, click to enlarge) and not the uncommon Pennsylvania native W. frutescens which flowers later and has much shorter strings of flowers. And it’s not just a plant or two, there must be half a mile of it in half a dozen different places over a stretch of a few miles. It's covering the trees(above, click to enlarge).

This is in the Delaware Water Gap National Recreation Area, where you’d expect some expert oversight of These strings of flowers of the Japanese Wisteria are longer and earlier than those of the native species. Image ©GardenPhotos.comthe habitat that’s being preserved, and one stifling mass of it is by the turn to the Pocono Environmental Education Centre. So why do the distribution maps say that it doesn’t exist in the area? I presume that, like the hellebores I wrote about a few weeks ago, it originated on a now-vanished property. When it was planned to flood this valley to create a reservoir many houses were vacated and removed - but not the plants. But it’s clearly been there a long time, so it’s strange that no one noticed -or, at least, no one reported it.

Of course, it looks spectacular but it completely smothers and weighs down the trees. Clearly anything growing on that scale – 30 to 40ft high, and more, through trees – must be doing some damage. I wonder if anyone has published any before-and-after wisteria research.

Virginia bluebells in blue - and pink

Mertensia virginica growing on a streamside in PA. Image ©
Driving close to where I spotted those naturalized snowdrops I mentioned here a few weeks ago – on my way back from my first session of cardiac rehab – I stopped for another look and found that the snowdrops, of course, were being overwhelmed by other vegetation including a star of our spring flora here in Pennsylvania – Virginia bluebell, Mertensia virginica (above, click to enlarge).

I haven’t come across lovely perennial this too often in this area but here it was growing in damp soil near a seasonal stream (dry at the moment). There were mature clumps, small plants and young non-flowering plants so it seems to be doing well.

Then, when I got home and was looking round the garden, I found that one of our clumps of the same plant A pink flowered shoot on a plant of Mertensia virginica in the garden. Image ©GardenPhotos.comhad produced two shoots with pink flowers (left, click to enlarge). Even on the usual blue-flowered plants the buds are pink, but soon mature to blue as they open. On these two shoots the flowers remained pink, though they seemed a little smaller than the nearby blue flowers.

White flowered forms with pale green leaves are also known, as well as plants with very pale blue flowers, and years ago I also saw plants with smoky bluish-purple purple flowers. They were all lovely. As soon as the clump sporting both pink and flowered shoots dies down in summer, I’ll lift it and split it to isolate the pinks. Not I just need to get my hands on the white one and the smoky one and the pale blue one…

There’s a fascinating chapter on these plants in Carol Gracie’s superb book Spring Wildflowers Of The Northeast.

Hellebore surprise in the Pennsylvania woods

Green hellebore, Helleborus occidentalis, in the Pennsylvania woods. Image ©
Out walking in the woods again yesterday, and I found ten clumps of hellebores! They look to me like a form of green hellebore, Helleborus occidentalis, with unusually large flowers; there was one very prolific clump (above, click to enlarge) and the rest were smaller, with some clumps too small to be flowering. All were scattered across an open east facing bank. Now hellebores are not native to North America – so what were they doing there? A couple of miles from the nearest house.

Actually, it was pretty obvious. The bank was at the edge of an unusually flat area; other non-natives were around including dense thickets of forsythia (below, click to enlarge - usually a sign of an old homestead), broad patches of Japanese pachysandra (Pachysandra terminalis) and bugle (Ajuga reptans), and three individual grape hyacinth (Muscari botryoides) bulbs with a single spike of flowers on each.

I’d say it was the site of an old homestead and this was confirmed by the fact that the whole area was relatively open compared with the surrounding forest. There was also what seemed to be the remains of a stone built water cistern, sunk in the ground and partially overgrown. And the trail along which I’d been walking when I spotted the hellebore clumps in the distance turned out to be a paved road that had been closed and become overgrown.

So, even though there was no sign of tumbledown walls, at some point in the past there must have been a house there and either the timber construction had simply rotted away or it been removed to be used again elsewhere. Helleborus occidentalis has a number of medicinal uses so it’s not surprising to see it on such a site.

Still – flourishing hellebores growing in the Pennsylvania woods 3000 miles from their native home in western Europe (including Britain) was quite a sight to see. Of course there are some people who’d have them ripped out as “invasive aliens” – see my recent piece on snowdrops. So I’m not going to say exactly where they are!
Forsythia growing in the woods is usually a sign of an old homestead. Image ©

Woodland native that's good in the garden

Anemonella thalictroides growing in an unexpectedly damp place. Image ©
Off out for my daily, cardiologist prescribed walk in the Pennsylvania woods yesterday, I came across two plants - uneaten by the deer that abound in this area – that while interesting to see in the woods are also good to grow in the garden.

The rue anemone, Anemonella thalictroides, is a lovely spring ephemeral, and a familiar native here in eastern North America where it’s often known as Thalictrum thalictroides - literally, the thalictrum that looks like a thalictrum. Surely that must mean that it’s an absolutely typical Thalictrum and meaning, I suppose, that all the other thalictrums are very definitely different.

Well, long ago that was the opinion. But in Europe and the rest of the world it’s now known as Anemonella thalictroides – in fact it’s considered so different from other thalictrums that it deserves a genus all of its own! This is a case of botanical science moving on and gardeners and botanists around the world taking their time to catch up.

Anyway, I was surprised to see it growing in soggy saturated soil by the side of a small stream as in these parts it’s usually seen in much drier conditions, such as trailside banks and rain-sheltered slopes.

You can see the wild plants I came across yesterday at the top (click to enlarge) but it’s true to say that their flowering season is very short – ephemeral indeed, so less useful in gardens. But like so many plants in the buttercup family - delphiniums, hellebores etc – there are many variants of Anemonella thalictroides and the double flowered forms make far better garden plants that the wild form as they bloom for so much longer.

‘Oscar Schoaf’ (below, click to enlarge) is a good example: not only are its flowers a rich pink, unlike the white or blush shade of wild forms, but they’re fully double so have more impact and last far longer than single forms. The problem is that plants are hard to come by, and they can be expensive. Propagation is by division - by scalpel!

Anemonella 'Schoaf's-Double' blooms for longer than the wild species. Image ©

Oh. I seem to have run out of time for discussing the other US native perennial that was such a standout – next time.