The Grand Prix rewards the rose varieties that best adapt to all of our regions and offers the home gardener a satisfaction guarantee regardless of the place of planting the rose. Whatever the climate and soil, roses must have a successful consistency in colors, the quality of the flower, plant vigor, resistance to disease, the flowering period. The competition roses are tested in different climatic zones of France, at seven sites – Annecy – Bordeaux – the Hay-les-Roses – Marseille – Montpellier – Nancy – Rennes The roses are grown without treatment with specialized gardeners and attentive biodynamisants receive some contributions.