Dickson's Rosa 'Lovestruck' is rose of the year 2018 and 20,000 are being grown to be available at garden centres by January 2018.
Harkness has won the prize for 2019, while Peter Beales is back in for 2021, as is Delbard.
Colin Dickson said: "It's great to win instead of a German rose. We've come so close, but this is the first since Irish Eyes in 2000. It's a pain Kordes winning every time but if it's the best, then you have to award it."
The rose is a cross between Precious Memory, Rover and US bestseller Knockout.
Philip Harkness said if UK breeders went four or five years without winning they should worry they are doing the wrong thing, but said "you can't shelter from global competition".
Fryer's launched Rosa Hope for Justice and Little Angel at the show, while Apuldram launched Oxana.