Founder Gilly Pollock has set up the guide to help British nurseries. She is scheduled to attend the RHS Malvern and possibly Hampton Court shows this year.
The first members, paying £400 a year, are Burncoose Nurseries and Duchy of Cornwall Nursery, both in Cornwall, along with Charles F Ellis and Caves Folly in Worcestershire and Lazy S in Monmouthshire.
Pollock said one of the ideas was to persuade gardeners who buy from garden centres to visit specialist British growers. "Buying from British growers stops imports and you get expert advice. People understand about supporting the local food industry but there is not an awful lot supporting local growers."
The website www.britishplant nurseryguide.co.uk features "jolly jaunts" - suggested trips to nurseries and surrounding attractions.