Purple Gem Dahlia Tubers

• Variety: Purple Gem
• Type: Semi-cactus
• Colour: Deep purple with lavender outer petals
• Flower size: 12cm across
• Height: 120cm
• Spread: 50cm
• Flowering: July to November
• Cutting: Yes. Striking in dark arrangements
• RHS AGM: No
• 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

Purple Gem: A Two-Tone Purple Semi-Cactus

Purple Gem is a semi-cactus dahlia with a two-tone purple colour scheme. The inner petals are deep, intense purple, while the outer ones fade to softer lavender, creating a gradient effect across each 12cm bloom. The spiky, rolled semi-cactus petals add texture to the colour play.

At 120cm with a narrow 50cm spread, it's tall and upright, needing staking but not taking up much lateral space. It flowers from July to November and the rain-resistant semi-cactus form handles wet weather better than flat decorative types.

Companions for Purple Gem

The deep purple works in dark and contrast schemes. Plant with Preference (soft apricot semi-cactus, 120cm) for a purple-and-apricot combination in the same spiky form. White Swan (white decorative, 120cm) provides clean contrast. Ambition (magenta-purple semi-cactus, 100cm) continues the purple at a shorter height.

Why Ashridge?

Our dahlia tubers are Dutch first-class quality, imported direct and hand-graded by us. We discard undersized tubers so you get a clump with viable eyes, ready to grow. Delivered by next-day courier from March, with our one-year plant guarantee, Feefo Platinum Service Award, and real people on the phone in Somerset. Browse our cactus dahlia range or the complete dahlia collection.

Frequently Asked Questions

Is Purple Gem good in the rain?

Better than decorative types. Semi-cactus petals shed water rather than cupping it. At 120cm it still needs staking, but the flowers themselves handle weather well.

Will Purple Gem grow in a pot?

At 120cm it's tall for a container. It'll work with a large pot and staking but it's happier in a border. For a purple dahlia that suits pots, Ambition at 100cm is more manageable. Our pots guide covers the options.

Is Purple Gem good for cutting?

The two-tone purple is striking in arrangements. Cut only fully open blooms. Full growing advice in our dahlia growing guide.