Dahlia 'Kelvin Floodlight'
Dahlia ‘Kelvin Floodlight’ is a giant decorative dinnerplate dahlia prized for its clear yellow blooms. It suits full sun and rich, free‑draining soil. It flowers from midsummer until frost in much of North America. The plant is tall and benefits from staking in windy sites. The large flowers are dramatic in borders and can be used for cutting with careful handling. It is frost‑tender and tubers must be protected or lifted in cold‑winter regions.
At‑a‑glance
- Group/Class: Decorative; giant ‘dinnerplate’
- Height × spread: 3-4 ft × 1.5-2 ft (0.9-1.2 m × 45-60 cm)
- Bloom window: mid‑summer to frost
- Color & flower form: clear yellow; very large double decorative
- Fragrance: 0 none
- USDA hardiness: grown as annual in most regions; may overwinter in ground in Zone 7 to 10 where soils are well‑drained
- Breeder / Year / Origin: unknown
- Cut‑flower notes: very large heads; stems can be heavy; typical vase life 3 to 5 days when cut at early maturity.
- Pet safety: avoid
How it differs
- Produces some of the largest blooms among dahlias.
- Yellow color reads bright at a distance compared with many garden types.
- Stems are thicker than average but still need support in wind.
- Not ideal for small containers due to stature.
Strengths
- Show‑stopping flower size.
- Summer‑long color where deadheaded.
- Works as a focal point in large beds.
Care in one minute
- Site: full sun; fertile loam with excellent drainage; pH near neutral.
- Water: provide deep, regular watering; avoid saturated soils.
- Feeding: moderate feeding; avoid excess nitrogen that promotes weak growth.
- Training: pinch once at 12 to 18 in; stake and tie stems; deadhead spent flowers.
- Overwintering: lift and cure tubers after frost and store around 40 to 45°F (4 to 7°C), or mulch well and risk in‑ground storage only in mild, well‑drained Zone 7 to 10 sites.
Watch‑outs
- Large blooms can catch rain and weigh down stems; staking helps.
- Bloom size and quality can drop in extreme heat or drought.
- Frost‑tender tubers need winter storage outside mild zones.
Best uses (tags)
cutting; borders; late season
Provenance note
Long‑grown exhibition‑type dinnerplate dahlia; specific breeder details are not verified in noncommercial records.
References
- Royal Horticultural Society – Dahlia ‘Kelvin Floodlight’ (plant profile)
- Oregon State University Extension – Dahlias in Oregon: overwintering options by USDA zonedahlias-oregon
- NC State Extension – Dahlia (care profile)
- ASPCA – Dahlia toxicity to pets
Written by: Your Flowers Guide editorial team
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