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Kew Pollination Collection Cosmos bipinnatus Seeds


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Tall, ferny foliage topped with bright, single blooms that range from white glacial white to carmine-pink.

This cheery cottage garden annual provides a bold splash of colour, mingling beautifully with summer-flowering perennials. Strong stems and a good vase life make cosmos an excellent choice as a cut flower. Pollinating insects will thank you for leaving some in the border where they provide a valuable source of nectar. Cosmos bipinnatus is quick and easy to grow, looking after itself once established. 

  • Sow from March to May in full sun
  • Height: 120cm. Spread: 60cm
  • 1 packet contains approximately 200 seeds
  • Attracts bees and other pollinators

As a fledgling business founded on the principles of friendliness, dependability and simplicity, we aim to deal with your order gracefully and efficiently so that you can devote your time to more important things. 

Our aim is to process your order within 24 hours of receipt and we expect it to arrive within 3-5 working days under normal circumstances.

Deliveries cost £3 for small, slim items that will slip into an envelope.

Most other deliveries cost £6 for any number of items, so don’t hold back!

Where age verification is required, a special service costing £10 is what we use to keep us all safe and sound.

Deliveries to far-flung UK locations may incur an additional charge.

Should you need to return an item, drop us a line at within 14 days of receiving your purchase, providing your name, order number and the reason for your return. We will let you know how to return your item.

Please visit our Delivery & Returns page for more information.

Sow Cosmos seed from March to May at a depth of 3mm in a good quality seed compost and cover the seeds with a very fine sprinkling of vermiculite. Place the seed tray in a propagator at a temperature of 18-25C or seal it inside a polythene bag. Keep the soil damp but not wet. Do not exclude light as this aids germination which usually takes 7-15 days.

When seedlings are large enough to handle, transplant into 7cm pots and grow them on in cooler conditions until large enough to plant outdoors. When cosmos plants are well grown and all risk of frost has passed, acclimatise them to outdoor conditions over 7 to 10 days. The best way to do this is by standing them outside during the day and bringing them inside at night. Transplant outdoors in full sun in any moist, well-drained soil at a distance of 45cm apart. Pinch out the growing tip of each stem when transplanting to encourage stems to branch and produce more flowers.

Alternatively, you can sow cosmos seeds directly outside from April until June. I often find these plants grow bigger and stronger than those sown under glass, although they'll flower a little later. A sowing made around Midsummer's Day will grow fast and the plants will produce flowers well into November. Autumn, when the nights are drawing in and the temperatures are dropping, is often when cosmos shines most brightly.

Water regularly and deadhead faded flowers to encourage more blooms to be produced throughout the summer and autumn.

For more help and advice on growing plants from seed, read my handy guide.


A great many of our favourite garden plants can be harmful if eaten or handled without gloves. This is rarely a cause for concern but it's always good to know what you are dealing with.

Apart from the production of pollen causing hayfever, cosmos does not commonly cause other allergic reactions.

Brand Focus

Thompson & Morgan

With over 160 years of experience, seed merchants Thompson & Morgan know a thing or two about plants and flowers. They are often the first to introduce gardeners to exciting new varieties.

The Kew Pollinators range of seeds has been specially created alongside experts at Royal Botanic Gardens, Kew to attract and support a wide range of pollinators, including bees, butterflies and beetles. Helping these pollinators to thrive is hugely important for our natural eco-systems as well as the health and productivity of our gardens. The seeds, in their striking packaging inspired by artwork from the Kew archives, will help to create an environment where pollinators thrive, with varieties chosen to help a wide range of different insects.

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Thompson & Morgan

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