Cosmos 'Purity' Seeds
If you want a plant that adds instant sophistication and calm to a border, 'Purity' is unrivalled. It produces large, pristine white, saucer-shaped flowers with a bright yellow eye, held high on airy, fern-like foliage.
This is a "workhorse" plant that looks delicate but is incredibly tough. It grows rapidly to form a large, shimmering cloud (up to 1.2m tall) that sways in the breeze. It is the ultimate filler for bouquets, adding a fresh, modern look to arrangements, and it glows beautifully in the evening light, making it a staple for white-themed "Moon Gardens."
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🌿 Understanding the Plant
Cosmos is a Half-Hardy Annual.
It originates from Mexico, so it craves sunshine. It is famous for its speed—growing from a single seed to a 4ft flowering shrub in just a few months.
The "Treat Mean" Rule: This is the secret to success. **Do not feed Cosmos!** If you plant them in rich, manured soil, they will grow into giant green monsters with no flowers. They flower best in poor, dry, "hungry" soil.
🌱 Growing Guide: How to Sow and Grow
Cosmos is reliable, fast, and perfect for beginners.
Germination:
Sow indoors from March to April, or directly outdoors in May once the frost has passed. Sow seeds 5mm deep. They germinate quickly (7-14 days) at 20°C.
Where to Sow:
They need **full sun**. They thrive in poor, sandy, or stony soil. Avoid heavy, wet clay or rich compost.
Care While Growing:
Pinch: When seedlings are 20cm tall, pinch out the top growing tip. This is crucial! It stops the plant growing one long, wobbly stem and encourages it to bush out, giving you triple the flowers.
Deadhead: Snip off dead flowers weekly to keep the show going until November.
📋 Plant Specifications
| Latin Name | Cosmos bipinnatus |
| Common Name | Cosmos 'Purity' |
| Hardiness | H2 (Half-Hardy - Needs Frost Protection) |
| Light Required | Full Sun ☀️ |
| Height | ↕️ 90cm - 120cm (Tall) |
| Spread | ↔️ 50cm |
| Spacing | 🌱 45cm apart |
| Great for | ✂️ Cut Flowers 👰 Weddings 🌙 Moon Gardens 🐝 Pollinators |
| Seed Count | Approx. 100 seeds per packet |
🤝 Perfect Garden Companions
The clean white of 'Purity' works with absolutely everything. Try these pairings:
- ❄️ Ammi Majus (Queen Anne's Lace): The White Garden. Combining the large, flat saucers of Cosmos with the lacy, frothy umbels of Ammi creates a stunning, textured "white garden" look that is very high-end.
- 🎀 Godetia 'Pink Bouquet': The Romantic Mix. The satin-pink, ruffled flowers of Godetia look beautiful sitting in front of the tall, white Cosmos. It’s a classic cottage garden combination.
📅 Sowing & Flowering Calendar
Sow indoors in spring. Plant out in June. Flowers July to November.
| Month | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow Indoors | 🟢 | 🟢 | 🟢 | |||||||||
| Sow Outdoors | 🟢 | 🟢 | ||||||||||
| Flowers | 🌸 | 🌸 | 🌸 | 🌸 | 🌸 |
🏆 Officially Recognised Excellence
This plant is a biodiversity champion. Cosmos bipinnatus is listed on the RHS Plants for Pollinators list, providing an easily accessible landing pad for bees and butterflies.
- Regular price
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£2.40 - Regular price
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- Sale price
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£2.40
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