Duration: Annual. Bloom Time: Summer to Fall. Height: 36 in to 48 in. Light: Full Sun to Part Shade. Soil Moisture: Dry to Medium. USDA Zone: 3a-9b. Germination: No pre-treatment needed. Sow seeds just below soil surface at 75F and water. Try something exotic with these huge blossoms, with tubular petals. A pretty mix of pink, red and white. Cosmos reach 3 to 5-feet in height, and won't fall over when planted close together as the feathery leaves 'lock together' and support each other. Blooms best in poor soil, and is drought tolerant. Happiest in full sun, they?ll grow in part shade without getting as tall. Attracts birds, bees and butterflies.