C. sulphureus. The intense dazzling yellow to reddish orange single flowers on this striking species Cosmos attracts bumblebees, birds, and beneficial insects, and looks terrific in a cut flower bouquet. Plant Bright Lights cosmos seeds in full sun. It's easy to grow in a variety of soils - tend towards the dry side. Its natural drought tolerance makes it a good candidate for xeriscaping. Plants grow to about 1m (3') tall, for the middle or front of a mixed border. Mix Bright Lights with dark blue and purple flowers like Blue Boy Centaurea or Rocket Larkspur Delphiniums for eye-catching contrast.
Cosmos will flower more in poor soil, rather than rich, so avoid manures and fertilizers. Pinch out the growing point when plants are around 45cm (18″) tall to encourage bushier growth and more flowering points. Water during very dry spells, but otherwise, Cosmos is well suited to xeriscaping. Seeds are easy to harvest and save.
These annual plants that are sometimes referred to as Cosmea.
Cosmos bipinnatus & C. sulfureus
Season & Zone
Exposure: Full sun
Direct sow from early March right up until mid-June. Several sowings will result in a very long bloom period. You can also start Cosmos indoors in February to early March for transplanting late March to mid-April. Seeds will sprout in 3-10 days. Optimal temperature for germination: 21-25°C (70-75°F).
Sow seeds very shallowly only a few millimeters (1/8″) deep. Thin or transplant to 20-25cm (8-10″) apart.