Cosmos bipinnatus - Kew Pollination Seed Collection

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 (64-77F) 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 (3") 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. Transplant outdoors in full sun in any moist, well drained soil at a distance of 45cm (18") apart. Pinch out the growing tip of each stem when transplanting to encourage stems to branch and produce more Cosmos flowers.

Seeds and garden supplies will normally be delivered within the time period stated against each product as detailed above. Plants, bulbs, corms, tubers, shrubs, trees, potatoes, etc. are delivered at the appropriate time for planting or potting on. Delivery times will be stated on the product page above, or in your order acknowledgement page and email.

Orders for packets of seed incur a delivery charge of £2.99.

Orders which include any other products will incur a delivery charge of £6.99.

Where an order includes both packets of seeds and other products, a maximum delivery charge of £7.99 will apply - regardless of the number of items ordered.

Large items may incur a higher delivery charge - this will be displayed in your shopping basket.

Please see our Delivery page for further details, and more information on different charges that may apply to certain destinations.

For more information on how we send your plants please visit our Helpful Guide on plant sizes.