Plant trials

Transatlantic flower awards

Dianthus barbatus (Sweet William) ‘Sweet Black Cherry’, Petunia ‘Cascadia™ Rim Magenta’, Lobelia ‘Waterfall Blue Ice’. Images ©Ball Colegrave
There’s been a flurry of announcements of awards from both sides of the Atlantic, awards that result from the voting of real gardeners looking at real plants growing in borders and containers rather awards given by committees sitting round a table. So let’s run through some of the awards for summer flowers, I’ll take a look at this year’s tomato taste tests another time.

BallColegrave Visitor’s Favourite (Blue Flag) Award

Chosen by visitors to the summer trials and displays at Ball Colegrave in Oxfordshire, the UK outpost of the Ball Horticultural Company). neither sell retail, you make your choice by sticking a blue flag by your chosen plant, the flags are counted every day, and the numbers tallied. Last year’s results are here.

This year home gardeners picked a new Dianthus barbatus (Sweet William), ‘Sweet Black Cherry’, as their favourite, a first-year-flowering type for borders and cutting in a rich deep red. This was followed by the dramatic white-edged, Petunia ‘Cascadia™ Rim Magenta’ for hanging baskets and in third place Lobelia ‘Waterfall Blue Ice’, from cuttings not seed and very resilient, and a very colourful basket plant. (All above, click to enlarge).

For trade visitors (garden centers, commercial growers etc) Petunia ‘Cascadia™ Rim Magenta’ came top with the big and bushy Begonia F1 ‘Whopper™ Mixed’ second and the vivid orange-and-gold Zinnia ‘Zahara Sunburst’ third. Put all the voting figures together and Petunia ‘Cascadia™ Rim Magenta’ was the winner. Last year Calibrachoa ‘Cabaret™ Bright Red’ came out top overall – not even in the top twenty this year.

American Garden Award
Verbena ‘Lanai® Candy Cane', Zinnia ‘Zahara™ Cherry', Impatiens 'SunPatiens® Compact Electric Orange' Images ©American Garden Award

Across the Atlantic, visitors to thirty one public gardens across the country voted for the American Garden Award – which, in spite of its name, is given to plants. All the top flower breeders around the world pick just four of their new plants to enter – and the visitors vote.

The winner for 2013 was Verbena ‘Lanai® Candy Cane' with its colourful striped florets in long lasting heads. This was followed by Zinnia ‘Zahara™ Cherry', another in the very adaptable Zahara Series but in rich cherry red  and third came Impatiens 'SunPatiens® Compact Electric Orange'. This is a very vivid orange colour, it takes the sun well and of course is tolerant of the mildew which has wiped out do many other impatiens. (All above, click to enlarge).

People's Choice Begonia Award
Begonia 'Peardrops', Begonia 'Volumia Rose Bicolour', Begonia 'Nonstop Golden Orange' Images ©RHS

At the Royal Horticultural Society’s garden at Wisley, just south of London, more than 2000 visitors voted to name their favourite begonia as part of the charity's People's Choice initiative. They were invited to vote for their favourite in three categories.

Amongst the Begonia Semperflorens Cultorum Group (fibrous-rooted begonias) planted in borders, the winner was ‘Volumia Rose Bicolour'. A more vigorous plant than traditional Semperflorens cultivars, it has large white and rose bicolour flowers that vary in colour intensity depending on the temperature.

Favourite Begonia x tuberhybrida (tuberous-rooted begonia) winner, planted in borders, was ‘Nonstop Golden Orange'. Introduced as long ago as 1971 and, as its name implies, it has an extended flowering period that runs from late spring to late autumn.

Finally the favourite begonia of any kind for containers or hanging baskets was ‘Peardrop', a lush rich salmon and golden orange hybrid bred by UK breeder Dennis Need. (All above, click to enlarge).


Tomato taste test - American style

'Sungold', one of the top tasting tomatoes in both the US and UK taste tests. Image ©Jacquie Gray/RHS
In my last post here, I looked at a British tomato taste test featuring tomatoes grown in the glasshouse of a large seed company in Oxfordshire in England. This time, we cross the Atlantic to Morningsun Herb Farm, a retail and mail order herb and vegetable nursery about 50 miles north west of San Francisco.

Their annual tomato tasting days began back in 2003 so they have a fascinating record of visitors’ favorites for flavor. For their 10th annual Tomato Day, last year, ninety three varieties were tasted by a large throng of visitors.

The hybrid tomato 'Sweet Chelsea' tasted better than many heirlooms ©Sakata SeedsTop of the tree came ‘Sun Sugar’, with ‘Sungold’ in second place – ‘Sungold’ also came second in the British test. These were followed by ‘Brandywine Sudduth’, ‘Sweet Chelsea’, ‘Rosalita’ and in sixth place ‘Matt’s Wild Cherry’. You can check the full list on the Morningsun Herb Farm website. In 2011 the top three were ‘Sun Sugar’, ‘Sungold’ and ‘Isis Candy’ followed by ‘Oaxacan Jewel’ and ‘Blush’ with ‘Snow White Cherry’, ‘Super Sweet 100’ and ‘Yellow Cherokee’ all equal. The voting was very close. But it’s worth mentioning that back in 2007 almost every singe person rated ‘Sun Sugar’ as “superb”. 'Sun Sugar', voted best tasting in the Morninsun Herb  Farm tomato taste test last year. Image ©Morningsun Herb Farm

So, in general, ‘Sun Sugar’ (cherry) and ‘Sungold’ (cherry) both of which scored exceptionally well every year, seem the most dependable tasty.

As with the British results, the varieties that did well were a mixture of modern hybrid varieties and older heirloom types. But, unlike the British taste test, all the voting took place on one day instead of being spread over a number of weeks. This is probably gives a fairer picture.

I should also mention that a couple of years ago New York magazine carried out their own very interesting tomato taste test involving two top New York chefs and an heirloom tomato expert.

Tomato Taste Test - British style


Everywhere you look, there are claims about how tasty are the tomato varieties offered by different seed companies. But, instead of relying on the seed company’s marketing department, isn’t the best way to simply ask people to taste a range of different tomatoes – and give their verdict?

Well, at Ball Colegrave, the British outpost of the Ball Horticultural Company (neither sell retail), that’s exactly what they did – last year, and the previous year as well. All the visitors who toured their summer trials – and who also voted for their Blue Flag awards for ornamentals – were invited to taste twenty five of their tomato varieties. All were grown under glass. The previous year they were offered forty seven varieties - which may be too taste boggling for any tongue.

I suspect that there’s a bias amobgst tasters towards familiar names which are likely to be tasted first and those with unfamiliar, or odd, names would tend to be sampled less often. But still...

The leader of the pack this year was ‘Sweet Aperitif’, with ‘Sungold’ in second place and ‘Chocolate Cherry’ third followed by ‘Suncherry Premium’, ‘Rosada’ and ‘Sweet Million’.

Last year, the top of the tree were ‘Sweet Million’, with ‘Rosada’ second and ‘Suncherry Premium’ third followed by ‘Trilly’ and ‘Sparta’ with ‘Sungold’ in sixth place.

Of course, this could hardly be called a rigorously scientific study. But the results do tend to confirm, over the two years, that gardeners will be very pleased with the flavour of ‘Rosada’ (mini plum), ‘Suncherry Premium’ (cherry), ‘Sungold’ (cherry) and ‘Sweet Million’ (cherry). And all four varieties, I should mention, have been awarded the prestigious Award of Garden Merit by the Royal Horticultural Society.

Next time, I'll be looking at an American version of this taste test.

A very unpredictable phlox

Assessing the trial of Phlox at the Royal Horticultural Society’s garden at Wisley, just south of London, back in the summer I was struck by a few things: the colour, the fragrance, how gorgeous some are (‘Blue Paradise’), how ugly a few are (‘Sherbet Cocktail’) – and the wild unpredictability of ‘Peppermint Twist’.

The trial is confined to varieties of Phlox maculata, P. paniculata and P. x arendsii, one hundred and thirty five of them, from a wide variety of sources but ‘Peppermint Twist’ stood out - for the right and the wrong reasons. The problem is that you get three plants in one.

The true ‘Peppermint Twist’ is a dramatic plant, each petal is pink in the centre and white at the edges creating the impression of pink flower with a white star. It’s colorful, it’s dramatic – but who knows how long your plant will stay that way?

‘Peppermint Twist’ is a sport of the pink-flowered ‘Candy Cane’ found on Jan Verschoor’s Dutch nursery back in 2001 (by Marc Laviana, President of Sunny Border Nurseries). The problem is that most plants revert to that pink ‘Candy Cane’ original after a year or two so you end up with both colors on one plant. Then, less often, it also reverts to the other colour in its flower – pure white. So you get three different flower colors on one plant!

Now, first thing: The true ‘Peppermint Twist’ is an amazing colour combination, a lovely plant. Secondly: If I want a bicolored phlox then I’m not happy about getting a plain pink one mixed in. And how did it get a plant patent if it’s so unstable? Thirdly: Why not grow the very similar Phlox maculata ‘Natascha’ instead? I’ve never seen it revert, and it never gets mildew either.

Finally, this is exactly what plant trials are for – whether at the RHS at the Chicago Botanic Garden or anywhere else; not only to reveal the best varieties, but also to reveal which varieties have problems.


Rotten research on tasteless tomatoes

Tomato 'Sweet Million' - rated highly for flavor by Raymond Blanc. Image ©Sakata Inc
This week the New York Times reports a paper in the journal Science which is said to reveal why modern tomatoes have no flavor. Apparently, the mutation that plant breeders bred out in order to prevent greenback (green shoulder) also “plays an important role in producing the sugar and aromas that are the essence of a fragrant, flavorful tomato”.

Harry Klee, a tomato researcher at the University of Florida in Gainesville, who was not involved in the research, is quoted in the Times as saying that the discovery “is one piece of the puzzle about why the modern tomato stinks.”

What planet are they on? Modern tomatoes don’t “stink”. Some don't taste of much, one or two are pretty much inedible, but there are plenty of modern tomato varieties with both a high sugar content and a wonderful flavor. Why base a serious piece of research on such prejudiced judegement - apart from the fact that it makes good copy?

Tomato 'Apero', rated highl;y for sweetness and flavour by the RHS. Image ©RHSIn 2007 the Royal Horticultural Society grew forty two different cherry tomatoes. You can read their report. Twelve were recommended for gardeners and received the RHS Award of Garden Merit. The sugar level was measured in each and the flavor assessed. Let me quote a few comments on three individual varieties: ‘Apero’ (left, click to enlarge), with a Brix-test result of 9.5% average sugar content, had a “good flavour”. ‘Golden Sweet’, with a Brix-test result of 10%, had a “good flavour and texture”. ‘Rosada’ (below right, click to enlarge) had a Brix-test result of 10.5%, the highest of all, and a “good sweet flavour.” True, it would have been better if they could have given a little more detail on flavor, but still – they rated them highly. All are modern F1 Hybrids. Tomato 'Rosada', rated highly by the RHS for sweetness and flavour. Image ©RHS

‘Sweet Million’ (top, click to enlarge), another modern F1 Hybrid, bred in Japan, also has an AGM but although it has a lower Brix test result of 7.1% the good balance of sweetness and acidity creates a flavour that was praised by renowned chef Raymond Blanc in the RHS magazine The Garden. He said this gave “a good tomato experience… juicy, excellent mouth-feel’”.

In fact Raymond Blanc took part in an extensive tomato taste test reported in The Garden in 2007. A number of varieties had good flavour, many of them modern. As well as ‘Sweet Million’ Raymond Blanc also liked ‘Santa’, another F1 Hybrid bred in Japan, and the opinion on ‘Santa’ was summed up by three judges: “Clean, meaty flavour. Well-balanced acid/sugar. Juicy fleshy texture.” ‘Santa’ is probably the most widely grown supermarket cherry tomato.

Another of Raymond Blanc’s favourites in the taste test was ‘Floridity’: "This is the best so far, good texture, excellent tomato experience," he said. The collective view of all the tasters was: “Outstanding flavour. Fleshy and juicy. Perfect acid/sugar balance”. This is a British-bred F1 Hybrid plum type.

Modern tomato varieties have no flavor? Nonsense.

So. Firstly. It’s simply not true that modern tomatoes have no sweetness and no flavor. Secondly, some modern varieties taste better than others; same as potatoes, carrots, apples and other vegetables. Choosing the right variety, modern or heirloom, is crucial. Thirdly, how you grow tomatoes makes a huge difference to the way they taste. Fourthly, if the researchers kept their tomatoes in the fridge all bets are off anyway – that’s a great way to ruin the flavor.


Transatlantic award winners - Echinacea and Vinca

OK, starting my quick look at award winning plants from both sides of the Atlantic, we kick off with a sparkling echinacea mixture and sumptuous vinca (not to be confused with groundcover vinca). For more on All-America Selections and Fleuroselect, see my earlier post.

Echinacea 'Cheyenne Spirit', Fleuroselect Gold Medal winner. Image © FleuroselectEchinacea ‘Cheyenne Spirit’
Fleuroselect Gold Medal winner Echinacea ‘Cheyenne Spirit’ (left, click to enlarge) is seed-raised coneflower mixture in six colours: orange, red, rosy-red, yellow, purple and cream. Not only does it bring this excellent range of colours (although no pure white), but the plants flower in their first year from a spring sowing, although seed needs to be sown in heat in late winter. (zone 4)

The single flowers are relatively uniform in size, and the plants all reach about the same size – 27-31in/68-80cm in height and 25-30in/64-76cm wide – whatever the colour. So the plants are very bushy. ‘Cheyenne Spirit’ looks great for sunny borders, and as a cut flower. And you can pick out your favorite color and divide the plants.

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Vinca 'Jams 'N Jellies Blackberry' Vinca 'Jams 'N Jellies Blackberry', All-America Selection. Image © All-America Selections
All-America Selection Vinca (Catharanthus) 'Jams 'N Jellies Blackberry' (right, click to enlarge) is an unusually richly coloured form of this annual in deep, not-quite-black purple that’s rather like a sun and heat loving version of Impatiens. Widely used in North America, and becoming more popular in Britain, these vincas are prolific and easy and don’t suffer from the downy mildew problems of Impatiens.

Reaching about 10-24in/25-60cm in height, depending on the summer climate, Vinca 'Jams 'N Jellies Blackberry' is a fine container plant, with silver foliage perhaps, and good in sunny borders.

Sow seed about eleven weeks before the first frost in your area at about 75F/24C and grow on at about 70F before hardening off and planting out.

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Ageing disgracefully

Argyranthemum,,marguerite,cobbitty daisy, fading. Images © GardenPhotos.com
I was looking at the trial of marguerites, Argyranthemum, sometimes known as cobbitty daisies, at the Royal Horticultural Society's garden at Wisley near London this week. One hundred and seven different varieties from around the world all grown in one place. A great opportunity to compare.

Two things struck me. Firstly, the old varieties like 'Jamaica Primrose' were only just starting to flower while modern varieties were covered in flowers. And already plants of the old varieties were generally much larger. But, more importantly, I was struck by the fact that while the flowers of some faded harmoniously the flowers of others deteriorated badly and as they faded they detracted from the display.

This is important because if you have to pinch off the flowers before they're finished the impact is dramatically reduced.

In the picture, the plant on the left is Summit Pink ('Cobsing') and the single flowers open in rose pink then fade to white. Very pretty and with a bonus: as the flowers finally die, the petals roll back as they turn brown and are hardly visible at all so no deadheading is needed.

On the right, San Vicente ('Ohmadsavi') opens a deep magenta rose then becomes paler and paler at the tips of the petals at the same time developing an odd little white crest in the middle. The result is a mess which could only be improved by cutting off half the flowers in the picture. What's more, as you can see, as the petals turn brown they remain on show. Not good.

The classic plant for ageing disgracefully is Achillea 'Fanal', often known as 'The Beacon'. As the tiny flowers first open, the flat heads are a brilliant scarlet. Then it all goes wrong, and as the later flowers are at their peak the earlier ones have turned the colour of dirty dishwater. Of course, you cut them off – but then the display is certainly much brighter, but very very thin.

The ability to fade harmoniously is not always a feature that can be easily appreciated when you come across an unfamiliar plant in flower in the nursery. But look carefully at all the plants on offer and it's often possible to look into the future and see how the flowers will mature.


The Dead Plant Society

DeadPlantCoffeCan I’ve been taking a look at the coffee can on the shelf where all the labels collect, the labels from the plants which are no longer with us. The Dead Plant Society. It's not necessarily as sad as it sounds.

Needless to say, it’s been added to recently as the fall clean up confirms the absence of plants which never peeped through on time in spring. But, also, a space behind a label may reveal something else.

Some plants are definitely very very dead, including the white mophead Hydrangea ‘Queen of Pearls’. It’sHydrangeaTag odd, some mophead/Hortensia hydrangeas do well here in chilly zone 5 and others get clobbered. “Can be grown in Zone 5 with good winter protection” says the website. No, I’m not going to protect some hydrangeas when others are happy without it. ‘Princess Lace’, in the same series, and ‘Forever and Ever Red’ are not dead.

Also very, very dead are:
Echinacea ‘Lilliput’ – not all echinaceas can cope with a combination of not quite enough sun and drainage not quite good enough either.
Aster ‘Marie III’ – don’t really care for these Yoder asters, the flower form is poor and I hate the way they go from ‘Marie’ to ‘Marie II’ and so on as they “improve” the individual colors. There‘s ‘Peter III’ as well, also dead!
Chrysanthemum ‘Will’s Wonderful’ – mentioned often on TP, most recently here. A great loss.
HibsicusTag Hibiscus ‘Peppermint Schnapps’ – yes, gone gone gone. Bred in tropical Florida. Not a good candidate for the frozen north. Stick with those from bred in icy Michigan by Walters Gardens.
Ranunculus ficaria ‘Double Bronze’ (and others) – I shipped just about all the double, and therefore non-invasive, varieties over from England but every one has now died. The single one thrives all too well on a river bank 150 miles away.

Also genuinely gone are some heucheras: weevils munching through the roots, I fear; Helleborus argutifolius: well, it does come from Corsica, zone 9; and all but two buddlejas… invasive? Hah! Not here.

But sometimes there’s just nothing behind the label
Achillea ‘Pomegranate’ – The deer ate (yes, I know achilleas are supposed to be deer-resistant)… The deer ate the ones planted outside the fence while they were soft and succulent and not sufficiently pungently off-putting. Those inside the fence are fine.
Aster novae-angliae ‘Snow Flurries’ – lovely white form of the New England aster found along a lonely road in Cattaraugus County, New York. Actually, it’s thriving. The birds moved the label to another bed. Thanks guys.
Athyrium ‘Ghost’ – It’s there, it’s gorgeous, its tag is fluttering down the driveway.AthyriumGhostTag
Vinca ‘Giant Steps’ – I think it grew so violently that it flung the label across to the other side of the garden. Currently escaping through the deer fence and looking at total eradication in the spring. So, yes, dead – one way or another.

And that’s only a sample from one coffee can… How many more cans are there?!

Ornamental rhubarbs - send your pictures to the RHS

Rheum trial RHS. Image: GardenPhotos.comThe 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.

 


Trials judging postponed by snow

Royal Horticultural Society judges were due to assess the winter foliage of the bergenias in the trial at the Society's garden at Wisley near London today. No such luck - can't do much judging when the plants are completely covered in snow!!

Bergenia-Trial-3-Feb-09-1-500  

In January, some plants in the Cortaderia trial were also still looking good, with their fluffy plumes still intact. Not today.

Cortaderia-Trial-3-Feb-09-3-600 

I don't think the judges were expecting to be assessing the Kniphofia (red hot poker) trial today - but it will be interesting to see if the results of the cold weather and unexpected snow covering.

Kniphofia-Trial-3-Feb-09-3-600 

Thank you to Ali Cundy of the RHS Trials Office at Wisley for these great pictures.