St Michael's Mount from the dahlia field

Photographs: Charles Francis


September 2015: Mike Mann gazes across a garden full of gorgeous dahlias. “People often say to me: ‘Which is your favourite?’” he says. “I can genuinely say that it’s one of the most difficult questions I ever have to answer.”  And that’s hardly surprising. As manager of the National Dahlia Collection, Mike has more than 1,750 varieties to choose from. “Every time I walk through the garden, one of the dahlias will shout at me: ‘This is my day!’ You never know which one it’s going to be.”  It might be showy ‘Mark Hardwick’, which boasts bright yellow grapefruit-sized blooms, or petite, pretty red pompon ‘Johann’.

 Dahlia 'Mark Hardwick' and Dahlia 'Johann'

The garden, based at Winchester Growers’ land at Varfell Farm, near Penzance, is at its brilliant best between July and September, and visitors are welcome to wander through a dahlia wonderland set against the stunning backdrop of St Michael’s Mount.

The collection was started in the late 1980s in Oxfordshire, and later moved to Duchy College Rosewarne, near Camborne. But its future was uncertain until Mike and fellow directors of Winchester Growers offered it a permanent home. “We’d all had a good living from horticulture, and we wanted to give something back,” he says. “We felt there was a duty to keep the collection going — and as soon as we saw it, we fell in love with it.”

More than 250 varieties have been added to the collection in the last 15 years, all more than 40 years old, although newer varieties are also available to buy. The dahlias are thriving in a climate which suits them literally down to the ground. “They are sun-loving plants which like moisture, but don’t like to be waterlogged. West Cornwall offers them that, along with summers which are not too hot, and mild winters,” Mike explains. “We have very free-draining soil at Varfell, and the number of days of frost we get in any year can be counted on the fingers of one hand.”

Dahlia field

However, he is keen to stress that dahlias can do well throughout the UK and beyond. ”We have quite a lot of customers in Scandinavia, and in Brittany and Normandy and parts of Germany. We’ve also sent dahlias to Greece, Slovakia and Lithuania.”

Dahlias originate from Mexico, and were brought to Spain 500 years ago. “The Spanish thought they had found a variety of potato, because it was a tuberous plant,” Mike says with a smile. “They quickly realised that it wasn’t edible, but they started growing the plants for their flowers, and then crossing different varieties.”

In Britain, the late Victorian era was the heyday of the dahlia, and there was a revival in the years after the Second World War when they became ‘Grandad’s allotment flowers’, but their popularity declined dramatically by the 1980s. “Dahlias were perceived as hard work, because you have to dig the tubers up each winter. But we like to think that since we took on the collection, we have regenerated interest in them. We took them to the Chelsea Flower Show in 2009 — the first time dahlias had been there for 25 years.”

Mike freely admits that there are two things dahlias do not offer: one is scent, and the other is the colour blue:  “If you see a blue dahlia in a picture, it’s been enhanced. The original palette was white and lilac, and red and yellow, and the genetics do not exist to get blue. But they will give you a huge display of every other colour through the autumn, right up until the first frosts. Dahlia imperalis is probably one of the things the Spanish first brought back from Mexico, and I have a lovely photo of one growing at the Eden Project on Christmas Day.”

For Mike, the saddest part of managing the collection is dealing with phone calls from would-be donors who say: “Grandad has passed away, and we’ve got all these dahlias — would you like them?” He sighs. “You want to say ‘yes’, but it‘s qualified with: ‘Do you know what they are?’ The usual answer is: ‘No — they’re just Grandad’s dahlias’. Unless they’re very distinctive, one yellow dahlia can look much like another.

“But whatever you want for your garden, it’s here somewhere, whether it’s something subtle or one of the more ‘in your face’ varieties. Sometimes couples come to our open days, and you can tell the wife wanted to come, and the husband is just doing his duty — but it’s very rare that they don’t come out with something they like.

“It could be ‘Sara G’, a classic cactus dahlia, with perfect summer colours of yellow and pink, or ‘Topaz Puff’, which has tight balls of dark red tubular blooms.

Dahlia ' Sara G'

 Dahlia ‘Sara G’ 


Dahlia 'Topaz Puff'

Dahlia ‘Topaz Puff’ 


And if you want something a bit different, you can use dark foliage varieties like ‘Bishop of York’ to great effect. ‘Hillcrest Regal’ has an interesting architectural form — and it provides bees and insects with breakfast, lunch and dinner.

Dahlia 'Bishop of York'

Dahlia ‘Bishop of York’ 


Dahlia 'Hillcrest Regal'

Dahlia ‘Hillcrest Regal’


“It’s also nice to have some home-bred material within the collection, like ‘Twyning’s Smartie’, which carries the jumping gene: some plants are completely red, and others have white petals.

Dahlia: 'Twyning's Smartie'

Dahlia ‘Twyning’s Smartie’ 


“Dahlias, with very few exceptions, do not come true from seed,” says Mike. “But if you want a bit of fun, go out in the autumn and collect some seeds. The chances are you’ll get a single dahlia – but it will be your single dahlia. And it might be a world-beater.”

Mike Mann