Millcroft Nurseries has moved to new premises in Warsash, near Southampton, consolidating the production from its former sites in Titchfield, also near Southampton, and Yapton, West Sussex.
The new site gives the company an additional 0.8ha of space, including larger glass and outdoor growing areas.
Still known as Rosemary Nursery, the site is named after the former business that stood on the site, a small-scale bedding venture, which closed four years ago.
Millcroft Nurseries assistant manager Tracy Puttock put the company's success down to "good quality and enthusiasm".
Millcroft Nurseries was set up 18 months ago by owner Darran Folk, who has worked in the horticulture industry since he left school. The company grows a range of bedding plants in 9cm pots and packs, and supplies garden centres including local chain Hillier.