How to Sow Pure White Cosmos Seeds 

Pure White Cosmos is an elegant annual flower that complements other garden plants beautifully. Its airy foliage and large, daisy-like flower heads create a striking display, growing up to 30–36 inches in height with blooms around 4 inches in diameter. Ideal for garden borders, pots, containers, or even as a windowsill plant, this hardy annual flowers prolifically throughout summer until the first frost. Easy to care for and drought-tolerant, White Cosmos is also a popular choice for cut flower arrangements. 

Is White Cosmos Easy to Grow from Seed? 

Yes, Pure White Cosmos is an easy flower to grow from seed. Follow these simple steps to ensure success: 

Indoor Sowing

1. Timing: Start seeds indoors 4–6 weeks before the last frost (typically from late February to April in the UK). 
2. Containers: Use seed trays or small pots filled with a fine grade seed compost for optimal results. 
3. Sowing Depth: Sow seeds at a depth of 1/4 inch (6 mm) and cover lightly with compost. 
4. Temperature: Keep the pots in a warm, bright location like a sun-facing windowsill or greenhouse. Maintain temperatures between 20–24°C for best germination. 
5. Moisture: Keep the compost moist but not waterlogged throughout the germination period, which typically takes 5–10 days. 

Outdoor Sowing

1. Timing: Wait until after the last frost, usually in late May or early June. 
2. Preparation: Choose a sunny spot with well-drained soil. Rake the soil to a fine tilth and remove any weeds or debris. 
3. Sowing Depth: Sow seeds at a depth of 1/4 inch (6 mm) directly into the soil. Water gently to settle the soil. 
4. Spacing: Once seedlings emerge, thin to approximately 12 inches apart to allow proper air circulation and space for growth. 

Caring for White Cosmos Plants 

• Watering: White Cosmos is drought-tolerant but will benefit from regular watering during prolonged dry spells. Ensure the soil does not completely dry out while plants are establishing. 
• Sunlight: Plant in full sun for the best blooms. Cosmos thrives with at least 6–8 hours of direct sunlight daily. 
• Feeding: Cosmos is low-maintenance and typically does not require fertiliser. Over-fertilising can lead to excessive foliage at the expense of flowers. 
• Deadheading: Regularly remove spent flowers to encourage continuous blooming throughout the growing season. 

Transplanting

1. Once seedlings reach 3 inches tall, transplant them to their final location. Space plants 12–18 inches apart to allow room for their bushy growth. 
2. Gradually acclimatise indoor-grown seedlings to outdoor conditions over a week before planting out. 

Why Grow Pure White Cosmos? 

• Self-Seeding: Healthy cosmos plants will reseed themselves, providing blooms in subsequent years without the need for replanting. 
• Cut Flowers: Perfect for vases and bouquets, their long stems and striking white blooms make them a florist’s favourite. 
• Pollinator-Friendly: The flowers attract bees, butterflies, and other beneficial insects, adding life to your garden. 

With its stunning blooms, adaptability, and ease of care, Pure White Cosmos is a must-have for UK gardens, adding charm and elegance throughout the summer months. 

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