The nursery held its third biennial Rudy Raes trial open week this week, showcasing improved breeding.
Burston's customers are mainly independent garden centres such as Blue Diamond, Squires, Haskins and Notcutts.
Managing director James Alcaraz said: "In 2016, we've gone back to basics and cut out some costly products and time consuming products that realistically, we didn't do very well.
"We're concentrating on core box bedding. We've seen some more demand in the past few years because fewer people are growing it because there's been such consolidation of the industry."
He said Burston was dropping a lot of pot bedding lines, which he said were over supplied in the UK and by the Dutch.
On roses, Alcaraz said: "We've seen a decline in sales over a few years and taken the view this is our last season and that will be it - we're pulling out of rose production. There's some issues with prices for roses."
Staff numbers are now 16 full-time, down from 24, and 14 seasonal students, down from 24.