Wyevale Nurseries sales and marketing director Adam Dunnett said: "We are delighted that Sir Roy will be our guest speaker for our open day. He has had a varied career and we think his talk will be very interesting."
A former director of the National Portrait Gallery and the Victoria & Albert Museum Strong has written extensively on the country's history and culture, as well as on garden design.
Dunnett added: "We are hoping the event will be entertaining and inspirational for those that attend. We will start the open day with a tour of the nursery. People will be able to see how we care for the broad range of products that we grow."
"We pride ourselves on the high quality of our plants and the incredible range we offer. We thought it would be a great idea to invite people to come and see it for themselves."
For more details on the open day which takes place on Wednesday, July 2 email Luke Powell at Wyevale Nurseries via firstname.lastname@example.org