The Proven Winners brand of plants, being released to the UK consumer market this year, will launch at Plymouth Garden Centre on 18-19 May.
The brand includes a wide range of plants including annuals, perennials and shrubs for the spring, summer and autumn seasons.
Proven Winners plants are produced in the UK by Kernock Park Plants in Cornwall, which has been working closely with the garden centre since October 2012 to introduce the brand.
Plymouth Garden Centre manager Fiona Newton said: "When asked by Kernock to get involved with this launch and provide feedback we were very keen to do so.
"This is an exciting opportunity to be the first garden centre in the country to see the introduction of the brand, and to help take planting recipes and innovative varieties on a step further, keeping customers interested, and helping them to create beautiful displays at home."
Kernock managing director Bruce Harnett added: "It was important that we worked with a local business, as we want to support our local economy, as well as bring value to the horticultural industry."
The weekend will include hanging basket and container planting demonstrations by expert Kevin Waters every hour on both days.