Cosmos sulphureus 'Bright Lights'
This warm‑toned seed mix of Cosmos sulphureus bears yellow, gold, orange, and red flowers. It stands out for heat tolerance and vivid color where summers run hot. It performs best in full sun with well‑drained soil and modest fertility. Bloom runs from summer to frost in many North American gardens. Plants are bushy and branching with a shorter, sturdier look than tall Cosmos bipinnatus. Grow it as a frost‑tender annual.
At‑a‑glance
Group/Class: seed mix; annual cosmos
Height × spread: 24 to 40 in (60 to 100 cm) × 18 to 24 in (45 to 60 cm)
Bloom window: summer to frost
Color & flower form: single to semi‑double in yellow, orange, and red hues
Fragrance: 0 none
USDA hardiness: grown as annual in all zones; frost tender
Breeder / Year / Origin: unknown
Cut‑flower notes: usable for casual bouquets; stems are shorter than tall C. bipinnatus types; expect a moderate vase life of about 4 to 6 days when cut early and conditioned.
Pet safety: safe; generally non‑toxic to pets; ingestion may cause mild stomach upset.
How it differs
- Species is C. sulphureus, not C. bipinnatus.
- Warmer palette of yellow to orange to red.
- More heat tolerant than many pink and white cosmos.
- Bushier habit and shorter stems for beds and borders.
Strengths
- Handles heat and summer sun well.
- Blooms freely with minimal care.
- Attractive to pollinators and beneficial insects.
- Good color massing in hot borders.
Care in one minute
- Choose full sun and well‑drained soil with low to moderate fertility.
- Water to establish then water when soil is dry to the touch; avoid soggy conditions.
- Avoid high nitrogen; light feeding is enough.
- Pinch once to branch; deadhead to prolong bloom.
- Direct sow after frost or set out transplants when nights are warm.
Watch‑outs
- Cut stems are shorter and vase life is moderate.
- May reseed and vary in color in the next generation.
- Susceptible to aster yellows where leafhoppers are common.
- Grey mold can appear in long wet spells.
Best uses (tags)
borders; massing; pollinators; heat‑tolerant; containers
Provenance note
‘Bright Lights’ is a widely sold seed mixture of Cosmos sulphureus in warm colors; sources note its heat performance and suitability for summer bedding.
References
- NC State Extension – Cosmos overview
- Royal Horticultural Society – Cosmos sulphureus ‘Bright Lights mixed’ (seed page)
Written by: Your Flowers Guide editorial team
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