The launch of the campaign was timed to coincide with last week's Chelsea Flower Show and has been created by Royal Mail's direct marketing agency Proximity London, which is responsible for all below-the-line activity for the special issues.
The campaign's aim is to promote the stamps where people expect to see flowers, with seed packets and specialist gardening magazines being targeted.
Early activity also included leaflets being handed out at the Chelsea Flower Show, rolled up to represent a bouquet of flowers.
Paul Malone, Royal Mail's direct marketing manager, said: "This is an excellent example of a fully integrated campaign showcasing the product in an unusual way and maximising the strength of each medium in full."
The campaign also includes online activity, which is being handled by Start Design.
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