Red Cactus Dahlia bulbs (technically tuberous roots) produce striking, fully double blooms with narrow, sharply pointed, and slightly rolled petals . Growing 30 to 40 inches tall, they bloom continuously from mid-summer through the first frost. They require full sun, well-draining soil (pH 6.0–6.5), and regular watering. [1, 2, 3]
Key Growing Specifications
- Planting Depth: Plant tubers 4 to 6 inches (10–15cm) deep with the “eye” or shoot-bud pointing upward.
- Spacing: Space them 12 to 24 inches apart depending on the mature variety size.
- Soil Requirements: Rich, well-drained soil fortified with organic matter or rotted manure.
- Sunlight: Full sun is required for best bloom production.
- Watering: Deep watering once or twice a week is recommended, avoiding waterlogged soil. [1, 2, 3, 4, 5, 6]
Maintenance & Care
- Staking: Tall varieties often need staking to prevent the heavy flower heads from snapping in strong winds.
- Deadheading: Regular removal of faded or spent flowers encourages continuous new blooms.
- Overwintering: In regions with freezing winters, tubers should be dug up in the late autumn, stored in a cool, dry, frost-free place, and replanted in the spring.
