A Jewel-Toned Cactus Dahlia for Dramatic Colour

Pre-order for dispatch end of February 2026.

The Dahlia 'Purple Gem' is a true treasure in the summer garden. As a classic Cactus variety, it features masses of narrow, rolled petals that radiate outwards to create a spiky, star-burst effect. The colour is a rich, saturated shade of deep amethyst-purple, which remains vibrant even in strong sunlight.

This variety is loved for its neat yet striking habit. It produces flowers in abundance on strong, wiry stems, making it an excellent candidate for cutting. 'Purple Gem' looks particularly stunning when planted alongside hot oranges or bright yellows for a high-contrast display, or mixed with soft lilacs for a harmonious purple theme. Vigorous and reliable, it provides a constant supply of "gems" for your vases from July until the first frosts.

SPECIFICATIONS

• Plant Type: Dahlia Tuber (Tender Perennial)

• Variety: Purple Gem (Cactus Type)

• Hardiness: Tender - protect from frost

• Flower Colour: Deep Amethyst Purple

• Flowering Period: July to October

• Sun Exposure: Full Sun

• Soil Type: Moist, Well-Drained, Fertile Soil

• Mature Height: Approx. 90cm – 100cm

• Mature Spread: Approx. 50cm – 60cm

KEY FEATURES

• Striking spiky "Cactus" blooms in deep purple

• Adds rich, jewel-toned colour to borders

• Excellent cut flower with long vase life

• Contrasts beautifully with bright or pastel shades

• Blooms continuously throughout summer and autumn

WHAT YOU'LL RECEIVE

You will receive top-quality Dahlia Tubers (Grade 1), ready to be potted up in spring or planted directly after the risk of frost has passed.

GROWING TIP

Cactus dahlias can hold rainwater in their complex petals, which can make the heads heavy. Always stake the plant securely at planting time to keep it upright. Feed regularly with a high-potash fertiliser (like tomato feed) to keep the rich purple colour intense and the flowers coming.

PERFECT FOR

• Adding Depth and Drama to Borders

• Purple and White Garden Themes

• Cut Flower Arrangements

• Cottage Garden Styles

• Filling Gaps in Perennial Beds

GROWING CALENDAR

• Planting: Pot up indoors in March/April or plant out in May/June (after frost).

• Feeding: July to September (High potash feed).

• Flowering: July to October.

• Lifting/Protecting: November (lift tubers to store over winter).

At The Rose Press Garden, we are passionate about providing gardeners across the UK with top-quality, healthy plants and bulbs, delivered directly to your door.

TRPG charges for delivery depending on the shipment locations and weight of items.

1st class P&P to UK is £5.95

2nd class P&P to UK is £4.50

P&P for heavy items such as plant support will be charged at £8