It’s back – resurfacing from the rotting depths of oblivion, the horror that was... Dendranthema!

What are they playing at?

Some years ago, after a great deal of careful study, the botanists decided that many of our old friends in the genus Chrysanthemum (garden chrysanths, cut flowers and pot ‘mums) should be moved into a new genus, Dendranthema. There was uproar – from gardeners, nurseries, from just about everyone. Even the botanists saw it as regrettable, even if it was botanically correct.

Eventually an important decision was made which acknowledged that the needs of gardeners and the horticultural trade should be considered alongside the accuracy of botanical judgement. Although there were sound botanical reasons for the move, the name was changed back to Chrysanthemum. Everyone was happy again. This was in 1997.

Not any more. And it’s not the botanists who are unhappy. Having agitated for the new name to be abandoned it’s nurseries who’ve brought it back. Dendranthema rides again.

First it was, the American wholesale branch of Blooms of Bressingham which is part of the Yoder group. Yoder bred five garden chrysanthemums, the Igloo Series (including 'Warm Igloo', above), and released them under the name Dendranthema. This was in 2006. It seemed like an isolated aberration, perhaps intended to distinguish these hardy garden varieties from other types - which are rather looked down upon by some keen gardeners. Now I see that the four varieties in the Autumn Crescendo series of garden chrysanths, derived from ‘Sheffield Pink’ and marketed by Walters Gardens (including 'Rhumba' in the second picture), are also being sold as Dendranthema.

Now I’m not saying these are bad plants, far from it. Both series look prolific and hardy, Igoo Series with a more mounded habit like a modern chrysanth, Autumn Crescendo more of an old fashioned type. But Dendranthema? Perhaps next they’ll dredge up the name Viorna for herbaceous clematis.

No. The whole point of the system of botanic nomenclature is that it's consistent and that people don't just decide to make up names or use old or invalid ones just because they happen to feel like it. So dragging Dendranthema back from the dead is just bewildering. Next stop: Horminum, the resurrected name for annual salvias. Just to be sure you don’t think you’re getting a sage bush.

Stop before it’s too late!

Driving up and down the A1, Britain’s main north-south route, in recent weeks we’ve been amazed by a vast and brilliantly colourful field of flowers by the side of the road. It turned out to be a field of echium (viper’s bugloss) – near Biggleswade in Bedfordshire, for the benefit of locals. 

Now until I looked it up I wasn’t sure why anyone would grow it on an agricultural scale but there it is, as far as the eye can see. The odd thing is, perhaps, not that it’s there at all – but that the flowers are a mixture of every shade of blue (including some lovely pale sky blue shades), every shade of purple, plus a few plants in rose pink and an even scattering of slightly taller white-flowered plants.  You’d expect an agricultural crop to be much more uniform. That field will produce enough seed to keep every seed company in the world supplied till the end of time. But of course that’s not why it’s there.

It turns out that echium oil is a good source of gamma-linolenic acid and stearidonic acid which are used in skincare and suncare products. The stearidonic acid has been “proven to decrease rigosity” – so there. So echium oil is used as a moisturiser, antiwrinkle cream, it has skin smoothing effects, promotes cardiovascular functions, it’s an anti-inflammatory and is used for the  treatment of joints, eczema and pre-menstrual syndrome. Now you know. 

And it’s early stages in the agricultural production of echium oil, but you can bet plant breeders are working to improve the oil content. And when they do, I guarantee their flowers will all be the same shade. And they’ll still be an impressive addition to the colours of our countryside. 

You can find out more about echium as a crop from the Interactive European Network for Industrial Crops here and from the University of York here.

Posts here have been thin recently, I’m sorry to say, partly because I’ve been preoccupied with posting for the Royal Horticultural Society from the recent Hampton Court Palace Flower Show – and judging there too. This is the largest flower show in the world, heldeach July in the grounds of Henry VIII’s palace on the southern edge of London.

It was spectacularly wet on the three days I was there, but you can find my posts on the interesting plants I found under canvas in the floral pavilions here.

One of the most impressive exhibits at the show was an exhibit of disas. Not many people have heard of them, but these gorgeous orchids are becoming popular as cut flowers while Dave Parkinson, from Yorkshire, is blazing a trail in encouraging gardeners to grow them. His exhibit was colourful, fascinating and the beautifully grown plants were meticulously staged.

Disas carry from one to half a dozen three-petalled, more or less triangular flowers held on vertical stems and come in vibrant red, orange, yellow and pink shades. They grow naturally on Table Mountain in South Africa.

Although they have a reputation for being difficult to grow, Dave Parkinson told me that it’s more matter of getting the conditions just right. “Grow them as cool as possible without freezing,” he told me. “I grow them without heat and cover them with fleece when frost threatens. Mine have taken -7C and although they looked unhappy the next morning they were soon looking good again. They didn’t let me down.

“And give them wet conditions, the same sort of conditions as you’d have for carnivorous plants. They won’t tolerate high salts, so they take very little feeding, and they reward you with these wonderful spikes of flowers which last up to six weeks in water.”

From all this you’ll gather that disas are unusual in being very colourful and impressive orchids which can be grown in a very low energy regime.

Having gathered together his collection, Dave began to make crosses to create new varieties, including 'Robert Parkinson'. He has increased hardiness and adaptability to less specific garden conditions as his chief aim and he now has some plants growing outside as a trial.

He also aims to broaden the colour range, for example to add the best scarlet colouring of the D. cardinalis to those with larger flowers. He is also crossing D. uniflora, whose large flowers are carried singly on the stems, with multiflowered types to create varieties with more, but larger, flowers.

It was great to see such dedication, and inspiration, resulting in such an impressive exhibit.

You can find out more about Dave Parkinson and his disas in this article from The Garden.

Dave Parkinson’s website is here, his advice on growing disas is here and his current list of the plants he has available is here.

We’ve been at the Hampton Court Palace Flower Show this week. Held in the grounds of Henry the Eighth’s palace alongside the River Thames on the southern outskirts of London, this is the largest flower show in the world. And, this year, the one with the most rain.

It was pretty much impossible to see the show gardens on press day on Monday as it rained virtually non stop for 16 hours. But I’ve been focusing on the floral marquees and posting about the plants every day for the Royal Horticultural Society’s website here.

The award for the best floral exhibit went to a superb herb stand from Jekka’s Herbs with an arch of Galega officinalis and a delightful stone terrace interplanted with flowering thymes. Indeed food was prominent everywhere at the Show. There was a fascinating and inspiring stand of chilli peppers in a wide range of varieties from Cookoo Box Chillies, the Growing Tastes Garden and Marquee housed a whole range of stands featuring edible plants as well as a traditional vegetable show and there was even a Thai floating food market on the lake.

Other exhibits in line for the best in the floral marquees included a pristine stand of lilies from H. W. Hyde and South African Disa orchids from Dave Parkinson who re-assured me that given the same conditions as you’d choose for carnivorous plants they are much less difficult to grow than people think.

Of the plants on show, in addition to those disas, it was great to see a whole range of different forms of Ginkgo biloba on the stand from the Big Plant Nursery and Dahlia ‘Candy Eyes’ from Hardy's Cottage Garden Plants is a dramatic new dark-leaved introduction - and this across the isle from a whole stand of fascinating dahlias old and new from Winchester Growers. The trailing yellow Scutellaria havanensis, from Hopleys Plants, looks to be an excellent newcomer for tumbling over the edges of raised beds while the new heucheras like ‘Tiramisu’, from French breeder Thierry Delabroye, on the stand from Plantagogo, are re-igniting enthusiasm for these invaluable foliage plants. The red-stemmed variegated hostas ‘Torchlight’ and ‘Rise and Shine’ from Goldbrook Plants hinted at the possibility of red-leaved hostas in a decade or two.

Everywhere you turn at the Hampton Court show there are plants – and, of course, at Hampton Court you can buy them and take them home there and then. Not so at Chelsea where you have to place orders for delivery later. How long before the Chelsea Flower Show moves from Chelsea to a site where there is space for nurseries to store enough plants for visitors to buy?