RHS Britain in Bloom is the most extensive horticultural campaign in the United Kingdom. It was first held in 1963 and initiated by the British Tourist Board based on the example set by Fleurissement de France. It has been organised by the Royal Horticultural Society (RHS) since 2002.

RHS Britain in Bloom organises and manages the National Finals. Finalists are nominated from their respective regions, and there is no direct entry into Britain in Bloom. Each of the sixteen regions of the UK, Scotland, Northern Ireland, Wales, England and Guernsey & Jersey manage their annual campaigns and competitions. 1000s of communities around the UK enter each year, participating in their local region’s “in Bloom” campaign. 

It is a popular and growing campaign, estimated to involve more than 100,000s volunteers in greening up their local area.

Since 2002, the awards have been based on the Royal Horticultural Society’s medal standards of Gold, Silver Gilt, Silver and Bronze; the winner is the entry judged to have most successfully met the judging criteria. Judging at the regional stage takes place around June/ July; judging for the national stage takes place in August. The results for the UK Finals are announced in September/ October.