Thomas A. Edison dahlia is a classic heirloom cultivar introduced in 1929, famed for its luxurious, deep magenta-purple blooms. Named in honor of the renowned American inventor and reportedly with his blessing, it remains one of the most popular decorative “dinnerplate” dahlias because of its vivid color and dependable performance.

Bloom Description:

• Large, fully double flowers up to 20–25 cm (8–10 inches) across.
• Petals are a rich, velvety purple that can appear lighter toward the edges.

Growth Habit:

• Grows to about 90–120 cm (3–4 feet) tall.
• Dark green foliage and sturdy stems, making it an excellent cut flower.

Flowering Period:

• Typically blooms from July through October, often continuing until the first autumn frost.

Growing Requirements Location:

• Thrives in full sun (6–8 hours daily) in a sheltered spot to protect large blooms from wind.

Soil:

• Prefers moist but well-drained, fertile soil enriched with organic matter.

Maintenance:

• Staking: Due to height and heavy flower heads, usually requires support with canes or stakes.
• Feeding: Benefits from a high-potash fertilizer (such as tomato feed) every two weeks during the summer to encourage more blooms.
• Deadheading: Regular removal of spent flowers promotes ongoing blooming throughout the season.

Overwintering:

• As a tender perennial, it is not frost-hardy.
• In colder regions, lift tubers and store them in a frost-free place after the first frost has blackened the foliage.
• In milder areas with well-drained soil, tubers may survive if protected by a thick layer of dry mulch.