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Cosmos seeds

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The seeds of Cosmos, flexible, elegant, very trendy, are sown in a nursery between 13 and 16°C (55.4 and 60.8°F) in April. Germination takes about 7 days. Transplant directly in place in mid-May after all risk of frost, spacing the plants about 30cm (12in) apart. Cosmos, popular plants, have an upright habit with a very bushy, light green foliage that is 30cm (12in) long and finely cut. The large flower heads are abundant from June to September. Easy to grow, they prefer light, dry, poor soils in sunny and warm locations. Plan for about 9 plants per square metre for a more beautiful effect. Tip: Requiring no maintenance, fill in the gaps between bushes or perennials with Cosmos for a guaranteed spectacular effect!

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  1. Cosmos: sowing and planting Tips

    Cosmos: sowing and planting

  2. How to sow cosmos Cosmos are easy-to-grow, long-flowering annuals (Cosmos bipinnatus, Cosmos sulphureus) ideal for borders, beds and pollinator-friendly gardens. Follow these steps for reliable results. When to sow - Sow under cover: 4–6 weeks before last expected frost. - Sow outdoors: after all risk of frost has passed and soil has warmed. - In mild climates: sow in autumn for early spring display. - For continuous flowering: sow every 2–3 weeks until early summer. Seed preparation and soil - No special pre-treatment required; seeds can be sown dry. - Choose well-drained, moderately fertile soil. Cosmos prefer lean to average soil; very rich soil encourages floppy growth. - Position: full sun for best flowering. How to sow - Surface-sow or cover very lightly: press seeds into soil or cover with about 2–5 mm of compost or soil. - Spacing: thin/plant out to 20–30 cm (8–12 in) for tall C. bipinnatus; 10–15 cm (4–6 in) for compact C. sulphureus. - Germination: 7–21 days at around 18–24 °C; keep soil just moist until seedlings establish. Practical care - Watering: keep moist while seedlings establish, then water sparingly—cosmos tolerate drought and too much water reduces flowering. - Feeding: little or no fertiliser; a light low-nitrogen feed encourages blooms without excessive foliage. - Pinching: optional. Pinch growing tips when plants reach about 10–15 cm to encourage bushiness and more flowers, but note pinching delays first blooms slightly. - Support: stake taller varieties in exposed sites to prevent flopping. Maintenance and problems - Deadhead spent flowers regularly to prolong bloom period. - Pests/diseases: generally trouble-free. Watch for slugs on young seedlings and powdery mildew in humid, overcrowded conditions. - To save seed: let heads dry on plant until brown, then collect seeds and store in a cool dry place. Quick tips - Sow directly where plants will flower to avoid root disturbance. - Use succession sowing for long season of colour. - Mix varieties for different heights and colours to create natural, airy displays. With minimal attention, cosmos will reward garden with abundant, long-lasting flowers attractive to bees and butterflies. Tips

    How to sow cosmos Cosmos are easy-to-grow, long-flowering annuals (Cosmos bipinnatus, Cosmos sulphureus) ideal for borders, beds and pollinator-friendly gardens. Follow these steps for reliable results. When to sow - Sow under cover: 4–6 weeks before last expected frost. - Sow outdoors: after all risk of frost has passed and soil has warmed. - In mild climates: sow in autumn for early spring display. - For continuous flowering: sow every 2–3 weeks until early summer. Seed preparation and soil - No special pre-treatment required; seeds can be sown dry. - Choose well-drained, moderately fertile soil. Cosmos prefer lean to average soil; very rich soil encourages floppy growth. - Position: full sun for best flowering. How to sow - Surface-sow or cover very lightly: press seeds into soil or cover with about 2–5 mm of compost or soil. - Spacing: thin/plant out to 20–30 cm (8–12 in) for tall C. bipinnatus; 10–15 cm (4–6 in) for compact C. sulphureus. - Germination: 7–21 days at around 18–24 °C; keep soil just moist until seedlings establish. Practical care - Watering: keep moist while seedlings establish, then water sparingly—cosmos tolerate drought and too much water reduces flowering. - Feeding: little or no fertiliser; a light low-nitrogen feed encourages blooms without excessive foliage. - Pinching: optional. Pinch growing tips when plants reach about 10–15 cm to encourage bushiness and more flowers, but note pinching delays first blooms slightly. - Support: stake taller varieties in exposed sites to prevent flopping. Maintenance and problems - Deadhead spent flowers regularly to prolong bloom period. - Pests/diseases: generally trouble-free. Watch for slugs on young seedlings and powdery mildew in humid, overcrowded conditions. - To save seed: let heads dry on plant until brown, then collect seeds and store in a cool dry place. Quick tips - Sow directly where plants will flower to avoid root disturbance. - Use succession sowing for long season of colour. - Mix varieties for different heights and colours to create natural, airy displays. With minimal attention, cosmos will reward garden with abundant, long-lasting flowers attractive to bees and butterflies.