Dahlia Thomas A. Edison

Dahlia Thomas A. Edison: A Monumental Deep-Purple Tuber

Create a dramatic and stately statement in your garden with the Dahlia Thomas A. Edison tuber. This robust, upright plant grows to a height of 110–125 cm with a bushy spread of 60–70 cm. Its strong stems proudly carry monumental, fully-double blooms measuring 15–20 cm across. The petals are a velvety deep-purple that intensifies toward the center, then lightens slightly on the outer rows, creating a rich violet glow. This stunning dahlia is a perfect choice for adding dramatic back-of-border color and high contrast when mixed with pastel varieties.

Dahlia Thomas A. Edison is an excellent option for large statement patio containers and grand floral arrangements. While the dinner-plate heads are heavy and water-thirsty, they can last 5–7 days in a vase if harvested at the half-open stage. They are ideal for creating “wow-factor” event bouquets and pedestal arrangements for short-term displays. With consistent dead-heading and maintenance, you can expect over 40 royal-purple blooms per plant throughout the long flowering season from early December through March.

Growing Calendar

• Plant tubers: mid-September (when daytime highs are ≤ 38°C).
• First blooms: early December.
• Peak display: December – March.
• Cut back / rest: early May.

Best Uses

• Dramatic back-of-border colour or mixed with pastel dahlias for high contrast.
• Statement patio containers (≥ 50 cm wide).
• Large event bouquets & pedestal arrangements (short-term displays).

Planting & Care Guide

• Light: Full sun ≥ 4 h; provide 30% shade-cloth if temperatures exceed 40°C during establishment.
• Soil: Deep, fertile, perfectly drained. Blend 5 L of mature compost and ½ cup of crab & lobster shell meal into each hole.
• Depth & spacing: Set tuber 10 cm deep, 50 cm apart; insert a stake at planting.
• Water: After shoots appear, deep-soak every 3–4 days; let the top 3 cm dry between irrigations.
• Feed (Fertilizing): Monthly low-nitrogen organic bloom fertiliser (~3-6-4) until February, then stop.
• Maintenance: Pinch at 40 cm for extra branches; dead-head or harvest promptly to expect 40+ royal-purple blooms.