Dahlia Black Jack

Dahlia ‘Black Jack’ is a striking cactus dahlia known for its dramatic dark colouring and bold flower shape. The pointed, slightly twisted petals create large starburst-like blooms in rich burgundy tones so deep they can appear almost black, especially in softer evening light. As the flowers mature and catch the sun, hints of dark crimson and velvety red emerge across the petals, giving the blooms remarkable depth and movement.

The spiky cactus form brings strong structure and contrast into summer borders, making this variety particularly effective among softer flower shapes and lighter planting palettes. Flower heads typically reach around 12–15 cm across and are held on long, sturdy stems well above the foliage, creating excellent presence both in the garden and in floral arrangements.

Growing to approximately 90–120 cm tall, Dahlia ‘Black Jack’ flowers continuously from mid-summer until the first frosts with regular deadheading. Its dark tones combine beautifully with soft pinks, creams, pale apricots, silver foliage, and ornamental grasses, while also working exceptionally well in richer, moodier planting schemes with deep reds and bronze foliage.

The long stems and architectural blooms make this variety highly valued as a cut flower, where it adds contrast, depth, and structure to bouquets without overwhelming softer companion flowers.

For best results, plant tubers in spring once the risk of frost has passed, in fertile, moisture-retentive but well-drained soil in a sunny, sheltered position. As with most taller dahlias, staking is recommended early in the season to support the stems as the large blooms develop.

A bold and sophisticated dahlia that brings dramatic colour and elegant structure to the late summer garden.