Cosmos 'Fizzy Rose' Seeds

Cosmos bipinnatus 'Fizzy Rose' is a robust Half-Hardy Annual (H2). Native to the sun-baked hillsides of Mexico, it is a Fleuroselect Novelty Winner, recognized for its exceptional garden performance and unique semi-double flower architecture. The additional rows of ruffed petals provide a 3D depth that is prized by modern floral designers.

The "Treat Mean" Rule: One of the most important aspects of Cosmos biology is its dislike of rich soil. If grown in manured ground or treated with high-nitrogen fertilizers, the plant will put all its energy into massive green foliage, often failing to produce any flowers at all. For the best picotee display, plant 'Fizzy Rose' in poor, dry, or sandy soil and avoid feeding.

Biodiversity Value: As an RHS Plant for Pollinators, 'Fizzy Rose' remains a vital resource for British bees and butterflies. Despite the double ruffles, the nectar and pollen are easily accessible, providing a long-season food source right through until the first autumn frosts in October or November.

Cosmos is one of the easiest and fastest plants to raise from seed, making it a perfect project for beginners or children.

How to Sow:
Sow indoors from March to May for early summer blooms, or direct sow outdoors in May or June once the soil has warmed. Sow seeds 5mm deep into moist seed compost. Germination is exceptionally rapid, typically occurring within 7-14 days at a constant temperature of 20°C. If sowing indoors, a bright windowsill provides enough light for healthy early growth.

Where to Plant:
They demand full sun and thrive in poor, well-drained soil. They are the ideal solution for filling large gaps at the back of a sunny border or for establishing an instant, high-volume picotee cutting garden. Space plants 45cm apart to allow their airy, bushy habit to develop fully without overcrowding.

Ongoing Care:
To encourage a sturdy, multi-stemmed plant, pinching is essential. When seedlings reach 20cm tall, pinch out the top growing tip; this prevents the plant from becoming too "top-heavy" and toppling over in late summer rain. Weekly deadheading is also vital—never let the flowers go to seed if you want them to continue blooming until the first November frosts.

The intricate pattern of 'Fizzy Rose' works spectacularly when paired with simpler or high-contrast partners from our available range:

• ☁️ Ammi majus: The Texture Match. The lacy white umbels of Ammi majus (Bishop's Flower) provide a soft, neutral backdrop that echoes the white centres of 'Fizzy Rose'. Together, they create a dreamy, "wild meadow" display that allows the vibrant magenta edges of the Cosmos to truly stand out.
• 🖤 Cornflower 'Black Ball': The High-Contrast Look. For a dramatic, modern aesthetic, pair the bright white and pink of the Cosmos with the deep, velvety maroon-chocolate of 'Black Ball'. The contrast stops the display from feeling too "sugary" and adds professional design depth to summer bouquets.

Sow indoors in spring or direct sow once the soil warms for a glamorous harvest of ruffed picotee blooms from mid-summer until the autumn frosts.