Dahlia ‘Black Jack’ is a striking semi-cactus variety known for its massive 6 to 8-inch dark burgundy-red blooms that appear almost black in certain lighting. Growing 36 to 48 inches tall, these tubers thrive in full sun and well-drained soil, blooming from mid-summer until the first frost. [1, 2, 3]
Key Plant Characteristics
- Flower Type: Semi-cactus, featuring long, spiky, and slightly inward-curving petals.
- Color: Deep blackberry-red to dark burgundy, creating a dramatic “gothic” contrast against its mid-green foliage.
- Height & Spread: Reaches 36 to 48 inches tall and spreads about 18 to 24 inches wide.
- Uses: Highly prized as a cut flower, in borders, or as a statement patio pot. [1, 2, 3, 4, 5, 6, 7]
Planting & Care Guide
- When to Plant: Plant tubers in the spring after all risks of frost have completely passed. [1]
- Soil & Sun: Requires full sun (at least 6-8 hours daily) and rich, well-draining soil. [1, 2, 3]
- Depth & Spacing: Bury tubers about 1 to 3 inches below the surface with the eye (growing point) facing up, spaced 18 to 40 inches apart. [1, 2, 3]
- Overwintering: Dahlia tubers are not winter-hardy and cannot withstand heavy frost. In colder climates, dig up the tubers in the fall and store them in a cool, dry, frost-free location for the winter.
