What to do now to display dazzling dahlias this summer
Its pigment-filled petals come in cool white, pale yellow, pastel pink, warm gold, bronze-apricot, royal purple and deep red.
They arrive in a season dominated by too many (frankly reluctant) daisies. Flower shape also varies, from simple single flowers and elegant bracts to prickly cactus or soft waterlily forms. Nothing else competes with them for late flower power and variety.
It is hard to believe that the first cultivated dahlias were simple, single-flowered species, and not the dazzling species we grow today. There are 35 species of these frost-resistant tuber plants, and they are found in high altitude areas, especially in the narrow strip that separates the two American continents.
They arrived in Europe in 1789, after sending seeds from Vicente Cervantes of the Mexican Botanical Garden to the Abbé Cavanels, director of the Madrid Botanical Garden. Lady Bute, wife of the British Ambassador to Spain, is said to have sent seeds here shortly afterwards.
The bees were immediately busy and the shell produced a great variety from very humble beginnings. Dahlias tend to be octaploid and some have eight copies of the same gene, so they resemble multi-flowered confetti that are tossed into the air once a bee visits. You don’t know where it will all lead. By 1816, there were already double and luxurious dahlias, and in 1836, the Royal Horticultural Society opened its own dahlia register.
It has recorded 13 different taxa, so all the forms we know today were already in existence by the mid-19th century. This genetic potential attracts many breeders and hobbyists, because you can breed a flowering dahlia in one short season and there is always an added element of mystery and surprise. You can never be sure what will turn out.
In the mid-19th century, dahlias became a rich man’s plaything. The tubers used to trade for £100 or more, the equivalent of £15,000 today. the A class of the newly wealthy She took full advantage of her newly arrived pink status symbol.
Biddulph Grange near Stoke-on-Trent in Staffordshire, one of the National Trust’s most delightful and delightful gardens, still includes James Bateman’s Dahlia Walk. Reginald Currie’s Welsh estate at Dyffryn, now the National Trust, has trialled thousands, and this garden is once again growing dahlias.
By the 1920s, there were many dahlia nurseries selling tubers to ordinary gardeners. Some of them are still with us today. The red-flowered peony ‘Bishop of Llandaff’, bred by Fred Tresidar of Cardiff in 1922, was selected by Bishop Joshua Pritchard-Hughes.
He probably liked the dark fern foliage as well as the bright red flowers. ‘David Howard’, a warm orange with decorative petals with khaki foliage, was a 1958 seedling raised by the late Suffolk nursery owner of the same name. It’s hard to believe that these two very different dahlias are so closely related. Both of these seasoned dahlias should be on your must-grow list, because they never fail to please.
The rollercoaster ride continued, but this time at a steep decline, because the dahlias were being snatched up by showrunners who wanted bigger and bigger flowers for the show seat.
That meant taking each stem apart, and the first dahlias I encountered in the 1950s looked like guards wearing busboys. Exhibition dahlias hampered the breeding process, because the new arrivals had to conform to a certain size and shape before they could be introduced into show classes. This selection process has seen many excellent dahlias eliminated.
The asymmetrical, sunset-inspired beauty, ‘Waltzing Mathilda’, wouldn’t be here if the breeders had made it – but I’m so glad it is!
By the 1970s, many dahlias were so large that they stuck out like a sore thumb, so very few gardeners bothered with them. Dahlia tubers failed to sell and specialty nurseries closed, but the late Christopher Lloyd of Great Dixter continued the business regardless. He became the bearer of the baton, because this colorful character knew a good thing when she saw one. ‘Hillcrest Royal’, a 1991 raspberry-pink cactus classic, was one of his favorites.
Gardener Fergus Garrett, Christopher Lloyd’s stepson, has a simple system for growing dahlias. It creates large gaps within the borders and is planted with spring beds such as tulips, upholstered roses and forget-me-nots. The spring bedding is removed by May and then the dahlias emerge into the same gap in early June.
By then, evening temperatures will have risen, so there is no fear of frost or cold shock. Dahlias don’t have to struggle through other things – something they really hate. Others, myself included, have custom cutting beds containing dahlias and annuals.
In the early 2000s, gardeners were wooed by bee-friendly, single-flowered dahlias. Twyning’s After Eight, a warm white with dark foliage, is still very popular, although ‘Magenta Star’ is my standard song.
The problem is that single dahlias need constant deadheading, because they stop flowering once they produce the shiny, pointed seed heads. It soon occurred to gardeners that dahlias with full petals needed less deadheading, because they last a week or more in the border.
It’s the trend of growing your own cut flowers that has given it a cult status in recent years and Sarah Raven has championed it all the way. The ‘Karma’ Dutch Series was bred for cutting and lasts longer in the vase.
We left the singles behind and fell in love with the large flowering dahlias, globes and globes, because they tend to have longer, stronger stems. It’s a rather stressful time of year, but I dream of covering my kitchen table with gorgeous dahlias for the summer.
The thought keeps me going.
Ten great dahlias to grow
Widely available, decorative and perfect for cutting, with large, slightly torn flowers on dinner plates in shades of watermelon pink. The foliage is green and not very inspiring, but most large flowering dahlias have coarse foliage. Five fill a vase! 4 feet
A spiritual man
This is a dark red dahlia centered around an anemone and has a windswept profile. The foliage is dark and split and this gives Solman a wild appearance straight from the Mexican mountains. Good long stems and more elegant flowers than most anemone-centric varieties, just a little whimsical sometimes. 3 feet
Absolutely pure, this shorter, anemone-centered dahlia is brimming with blooms, with an elegant ring of slightly mirrored petals surrounding a raised cushion of flowers. ‘Josie’, named after head gardener Sarah Raven, is a fiery orange sport. Good for front end, or bowl. 3 feet
This small, ornamental dahlia has dark red flowers with a plain chocolate center. There is a velvety patina to the overlapping petals and these dark dahlias mix well with soft orange and pink. One of Karma’s cut flower series. I also adore Sam Hopkins’ similarly exciting film. 3 feet
Thomas A. Edison
Ornamental dahlias look right into your eyes, and these very popular 1929 deep purple dahlias are as stunning as they are full of blooms. ‘Lilac Time’ is a paler sport and ‘Admiral Rawlings’ (another purple) is a giant lilac from behind the border. 3 feet
This semi-cactus plant has white flowers with a delicious green touch, so it’s not too icy. It is very flowering, with twisted petals, and its blooms never fail. 3 feet
A rounded spherical dahlia with overlapping peachy-pink petals surrounding a purple center. The dark eye and picot edges on the inner petals add extra definition. 3 feet
This fresh, light pink ornamental dahlia, with flowers resembling a water lily, has purple undertones and a pale cream middle. It cuts really well and some of the petals are crushed. 4 feet
The dahlia’s radiant apricot-brown ball has masses of petals that appear to make teardrop-shaped drops. The perfect foil for exciting colours. 3 feet
Mysterious knockout illusion
The chocolate foliage and single yellow-brown flowers of this New Zealand dahlia capture the serene mood of late summer. It was originally named “Knockout” by breeder Keith Hammett, who also bred “Magenta Star”. 4 feet
Suppliers: House rose plants, Riverside Bulbs, Gracie Farmer
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