Cornel Dahlia Plants & Tubers Dahlia Tubers

• Variety: Cornel
• Type: Ball dahlia
• Colour: Deep maroon-red with a hint of purple at the centre
• Flower size: 7 to 10cm across
• Height: 120cm
• Spread: 70cm
• Flowering: July to November
• Cutting: Excellent. Strong stems, perfect bouquet size, good vase life
• RHS AGM: No (but AGM holder Cornel Brons is a sport of this variety)
• Origin: Cor and Nellie Geerlings, Heemstede, Netherlands, 1994. Named after both of them: Cor + Nel = Cornel
• Sold as: Single tubers, hand-graded, Dutch first-class quality
• Plant outdoors: March to July, when soil reaches 15°C (typically May in most of the UK)
• Delivered: From March. Collection from Castle Cary also available

Cornel: The Cut Flower Workhorse from a Legendary Dutch Nursery

Cornel was bred in 1994 by Cor and Nellie Geerlings of Heemstede in the Netherlands. They named it after themselves: Cor plus Nel. The Geerlings nursery is the same one that produced Glorie van Heemstede (winner of the Stredwick Medal, one of the dahlia world's highest awards) and many other celebrated varieties. Cor was made honorary member of the English Dahlia Society. This is a plant with proper lineage.

The flowers are a deep, rich maroon-red with a purple flush at the centre, 7 to 10cm across, with velvety petals packed tightly in the classic ball form. The stems are long, straight and strong, the kind that hold flowers upright without any help, which is exactly what you want in a cut flower. Cornel is a workhorse of the commercial cut flower industry for that reason: it produces masses of blooms in the perfect bouquet size on stems that don't bend or break.

It's also the parent of at least five known sports, including Caitlin's Joy. The entire Cornel family shares the same weather-proof form, tireless productivity and reliable tuber storage. The matriarch of a dynasty.

Cornel in the Border

The deep maroon balls provide structure and colour depth. Plant Cornel behind Cafe au Lait (milky coffee dinnerplate) for one of the best contrasts in the dahlia world: tight dark globes against huge pale ruffles. For a warm scheme, pair it with the apricot dinner-plates of Fairway Spur (120cm, same height) and the golden yellow of Golden Sceptre (ball, 90cm). Helenium and late-season Penstemons are natural companions in the same warm register.

Why Ashridge?

Our dahlia tubers are Dutch first-class quality, imported direct and hand-graded. We discard undersized tubers so you get a clump with viable eyes, ready to show you what they can do. Delivered by next-day courier from March, with our one-year plant guarantee, Feefo Platinum Service Award, and human support from the team in Somerset. Browse our other ball dahlias or the complete dahlia collection.

Frequently Asked Questions

Why is Cornel so popular as a cut flower?

Three things. The 7 to 10cm ball shape is exactly the right size for bouquets and arrangements without overwhelming a vase. The stems are long, strong and naturally upright. And the production is relentless: cut a flower and the plant pushes out another. Commercial growers use Cornel precisely because it keeps delivering.

What's the connection between Cornel and Caitlin's Joy?

Caitlin's Joy is a sport of Cornel, meaning it appeared as a natural mutation on a Cornel plant. Same tough, productive habit, same weather-proof ball form, but bright pink instead of maroon. There are at least five known sports in the Cornel family, all inheriting the mother plant's reliability.

Can Cornel grow in a pot?

At 120cm tall, it's on the large side for a container but manageable if you use a pot of at least 35cm across and deep, stake it, and feed regularly. It's really at its best in a cutting bed or deep border where it has room to spread to its full 70cm. Our container guide has advice on what works in pots.

Is Cornel good in the rain?

Better than most. Ball dahlias are inherently more rain-tolerant than decorative types because the tightly rolled petals don't cup water. Cornel's family is specifically noted for being weather-proof. It won't shrug off a deluge, but it handles British summer rain much better than a dinnerplate variety.

How do I overwinter Cornel tubers?

Cornel stores well. After the first frosts, cut stems back to 15cm, lift the tubers, brush off soil and let them dry for a day or two. Store somewhere cool, dark and frost-free. Check monthly. Cornel tubers are typically tough and store more reliably than some fussier varieties. Our overwintering guide covers the whole process.