Discover the beautiful National Dahlia Collection and the person who helped save it from disappearing

Over the Easter weekend in 2021, a steady stream of cars, vans, trucks and trailers wound back and forth through narrow Cornish lanes to an empty field near Camborne. Each was piled high with black plastic crates, and within every one of these 5,500 crates, nested in loose, dry compost, lay tubers – sometimes as many as eight, sometimes just an irreplaceable singleton. The precious mother stock of the National Dahlia Collection, it was rescued by a devoted band of volunteers led by a local horticultural lecturer Louise Danks.

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The collection’s new home is a half-acre triangle of grassy field belonging to the Kehelland Trust – a charity offering horticultural therapy and training to adults with learning or physical disabilities. Previously used to grow brassicas, the site is conveniently sheltered by high hedges, and, crucially, the soil is light, sandy and free draining – ideal for dahlias, which hate to get their feet wet.

It had been touch and go. First established in Oxfordshire in the 1980s, the collection had moved with its founder, David Brown, to Duchy College Rosewarne in Cornwall, then moved once more to Varfell Farm, near Penzance, in 1998. Here it remained for over two resplendent decades – growing in size and scope to showcase 22 of the world’s 41 species and more than 1,700 cultivars. But by 2020, the commercial dahlia business that supported the collection was no longer viable, and the decision was made to close the site.

Louise was appalled. She had worked at Rosewarne as a student, deadheading dahlias, and joined the Varfell team as an adult, overseeing the production of some 40,000 rooted dahlia cuttings a year. She had won Gold medals for her dahlia exhibits at Chelsea and, most importantly for her, had learned dahlia cultivation from the two finest growers in the business – Varfell’s Mike Mann and hybridiser extraordinaire Mark Twyning (creator of the sumptuous Dahlia ‘Twyning’s After Eight’, with leaves the colour of chocolate and large single flowers with the unnatural pallor of mint cream).

Jump to discover Louise's favourite dahlias

Although by this time she was no longer at Varfell, she felt the collection was an important part of her history, and Cornwall’s horticultural heritage. “There was this niggling voice in my head, saying ‘Someone should do something about it’. It’s such a valuable collection botanically, it would be terrible if it were lost. And eventually it became clear that the someone had to be me. The trouble was, I didn’t have any land.”
By now, Louise was teaching at Duchy College Rosewarne. If, she tentatively asked, she could secure the mother stock, would the college allow her to store 5,000-plus crates in an empty polytunnel over the winter? A little to her surprise, they agreed. Working with her father, Chris Danks, along with the help of family and friends, the dahlias were moved to Rosewarne. “They were stacked up in towers of crates, higher than me. But obviously, this was only a stop-gap solution: a permanent home had to be found before the tubers started growing. Luckily, it was a really late spring – I think I was the only grower in the UK who was happy about that.”

The polytunnel had to be emptied by Easter. Happily, Kehelland’s offer came just in the nick of time. Strip beds were hastily dug in the field, an electric fence erected to discourage the many rabbits, and the hard work of preparing the soil and planting the tubers began. The collection was arranged, as before, in classification order, organised by flower form, size and colour. (The American Dahlia Society specifies 19 flower forms, while the National Dahlia Society of the UK recognises a paltry 15.) But on a site a quarter of the size of the previous one, the plants were squeezed in much closer together. “It has its advantages,” says Louise. “The plants prop each other up and it makes being among them a truly immersive experience.”

Sizzling with colour and loud with birdsong, the dahlia field offers a sanctuary of delight

From July to November, there is no more beautiful place to be. Sizzling with colour and loud with birdsong, the dahlia field offers a sanctuary of delight for both Kehelland’s clients and the loyal volunteers who keep the collection going. All have day jobs, not least Louise (who is learning and content manager for the RHS) and her father, a landscape gardener, who are the backbone of the team – hard at work on the collection every Saturday and Wednesday evening. “Deadheading on a sunny evening is a lovely task,” says Louise, “and with a lot of help we keep on top of it. It’s more difficult to get volunteers to barrow 45 tonnes of mulch in the winter.”

Most summers, the collection is open to visitors – although this summer it will be closed while Louise and Chris tackle the mammoth task of lifting and dividing all the tubers. “But we’ll be back next year,” she promises, “bigger and better than ever.”

It was never her ambition to grow only dahlias, she says. “I certainly didn’t ever set out to have the National Collection. But I grew to love them. They are genuinely interesting plants, and there’s something for everyone – whether a giant decorative that looks like something from The Rocky Horror Picture Show or beautiful Dahlia merckii that wouldn’t look out of place in a Jekyll border. There are some very sophisticated dahlias; there are also those that are totally hysterical and ridiculous. There aren’t many other genera of plants you can say that about.”

Louise’s top 17 dahlias

Dahlia ‘Cameo’

This strong, upright waterlily dahlia from Australia bears perfectly arranged creamy-yellow petals with a hint of lemon at the centre. Elegant flowers 7-10cm across will last a full week in a vase. Height and spread: 1.75m x 1.2m.

Dahlia ‘Apple Blossom’

A collarette dahlia – a category introduced in the early 1900s. The inner ‘collar’ lying on a flat single flower makes it an excellent choice for encouraging pollinators. Very popular with florists and flower farmers alike due to its subtle tones. 1.2m x 1m.

Dahlia ‘Glorie van Heemstede’

Offers waterlily blooms of a refined lemon yellow, up to 15cm across. A strong dahlia with good foliage,
impressive in both the garden and the vase. 1.3m x 70cm. AGM*.

Dahlia ‘New Baby’

A reliable plant, offering many flowers of vibrant orange and 5cm across over a long period. Graceful enough for dainty arrangements, zingy enough to lift a hot border or bob through a grass garden. 90cm x 75cm.

Dahlia ‘Striped Vulcan’

A large cactus dahlia with tousled blooms, wildly striped and spotted, up to 20cm in diameter. A cultivar that is always a favourite with the children who visit – simply fun. 1.2m x 1m.

Dahlia ‘Pooh – Swan Island’

A dahlia that makes everyone smile. A deservedly popular and reliable collarette, neat in form, with prolific red and yellow blooms (75cm across), loved as much by pollinators as people. 1m x 50cm. AGM.

Dahlia ‘Weston Pirate’

A miniature cactus dahlia with blooms of no more than 10cm across, in a clear singing red. 1.2m x 1m. AGM.

Dahlia ‘Hazel Bear’

An orchid-flowered dahlia Louise named for her youngest daughter. Pink, yellow and white blends on quill-shaped petals. As Louise says, it is “absolutely beautiful, just like Hazel”. 1m x 1m.

Dahlia ‘Twyning’s After Eight’

A striking dahlia with chocolate-coloured foliage and creamy-white single flowers. 1.2m x 60cm. AGM.

Dahlia ‘Karma Yin Yang’

Bred for the cut-flower market, this is exceptional in a vase, with long, strong stems supporting glamorous blooms 12cm across. With petals of iridescent red tipped in white, this dahlia is a showstopper. 1.2m x 1.2m.

Dahlia merckii

The best species dahlia for the average garden, it is reliably hardy, producing a mound of finely cut leaves, liberally adorned with dainty, pinky-mauve single flowers approximately 5cm in diameter. 2m x 1m.

Dahlia ‘Karma Sangria’

A cactus type with striking quilled flowers reaching 15cm across, borne on strong stems. Barbie-pink merges boldly into golden yellow. Also an excellent foil for grasses in the garden. 1m x 60cm.

Dahlia ‘Limozine Dean’

Beyond floriferous with cerise petals and a yellow centre, which makes it glow from the other side of the field. 1.75m x 1.25m.

Dahlia Happy Single Wink (= ‘HS Wink’)

Glowing pink petals stained plum at the base. It’s one of the Happy Singles series of small dahlias with pollinator-friendly single flowers set off by dark purple-bronze foliage. 60cm x 40cm.

Dahlia ‘Franz Kafka’

A floriferous pompom with perfectly round balls of bright lilac-pink, 5cm in diameter. 1m x 50cm.

Dahlia ‘Violet Lou Lou’

A big shaggy bi-coloured decorative dahlia with D. ‘Café au Lait’ in its parentage. It’s one Louise has named for her eldest daughter. As she says: “They are both complete stunners.” 1.3m x 1m.

Dahlia ‘Royal Blood’

An unusual collarette cultivar that offers deep-red flowers with yellow centres from midsummer to the first frosts. “It’s leggy but in a good way,” says Louise. 1.6m x 1.2m.

*Holds an Award of Garden Merit from the Royal Horticultural Society. Most dahlias have a hardiness rating of RHS H3, USDA 7a-10b.

USEFUL INFORMATION
Address Kehelland Trust, Kehelland, Camborne, Cornwall TR14 0DD. Web kehellandtrust.org.uk

The National Dahlia Collection will open again next year from July to October. For more information, visit plantheritage.org.uk