Warm-Season Annual Wildflower
Sulphur Cosmos
Cosmos sulphureus
A heat-tolerant annual with brilliant yellow and orange flowers for pollinator plantings and mass summer color
Sulphur Cosmos is a vigorous warm-season annual known for bright yellow, gold and orange flowers carried above finely divided green foliage. It thrives in sunny, warm conditions and provides strong seasonal color through the summer growing period. Its open flowers are readily visited by butterflies, bees and other pollinating insects.
Wildflower Characteristics
Why Plant Sulphur Cosmos?
Sulphur Cosmos is a strong choice for warm-season wildflower plantings where heat tolerance, vivid color and pollinator activity are priorities.
Heat Tolerant
Performs well during warm weather and is particularly useful for extending wildflower color into the hotter portion of the growing season.
Pollinator Value
Open flower heads attract butterflies, bees and other beneficial insects throughout the bloom period.
Bright Warm Colors
Flowers range from yellow and gold to deep orange, providing highly visible summer color.
Vigorous Growth
Establishes quickly under warm conditions and develops a branching canopy with numerous flowering stems.
Where It Fits
Best Uses for Sulphur Cosmos
Sulphur Cosmos is especially effective where strong summer flowering, pollinator habitat and warm-season performance are desired.
Establishment & Management
Growing Sulphur Cosmos
Sulphur Cosmos establishes readily from seed once soil temperatures warm and performs best in full sun with reasonably well-drained soil.
Planting Window
Plant after frost danger has passed and soils begin to warm. Warm conditions encourage rapid germination and establishment.
Planting
Sow relatively shallow and provide good seed-to-soil contact. Avoid excessive burial of the seed.
Sun & Soil
Full sun is preferred. Sulphur Cosmos tolerates relatively lean soils and does not require high fertility for strong flowering.
Reseeding
Plants can produce abundant seed. Allow mature seed heads to develop where future volunteer plants are desired, or remove them earlier to limit reseeding.
Warm-Season Performer
Bright Color When Summer Heat Arrives
Sulphur Cosmos differs from the familiar pink-and-white Cosmos bipinnatus types by producing warm yellow, gold and orange flowers and performing particularly well in hot summer conditions. It is a useful species for extending wildflower color and pollinator resources later into the warm season.
Looking for Sulphur Cosmos Seed?
Contact Weaver Seed for current availability, quantities, packaging or help incorporating Sulphur Cosmos into an annual wildflower, pollinator or custom seed mixture.
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