Certified GKH Gardening Expert
Seeds are located in the spent flowers. This article will help with collecting seeds from flowering plants: https://www.gardeningknowhow.com/ornamental/flowers/fgen/harvesting-garden-seeds.htm Additionally, most garden centers/nurseries will have these seeds/plants available. You can also perform a Google search to locate the nearest seed supplier or obtain a catalog for ordering the seeds elsewhere. There are many seed swapping garden forums that may offer the seeds as well.