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.
