Nigella is one of those flowers that actually prefers the cool soil of early spring. In Zone 6b, I start sowing my nigella seeds in late winter and continue sowing through early Amazon.com : Outsidepride White Blutopia Bacopa Seeds 10 Pcs Low Maintenance Perennial Flower Seeds with Cascading, Vibrant Blooms & Trailing Growth Habit, for Containers, Baskets, & Window Boxes : Bacopa Plants : Removing seed pods. YouTube 19 Plants with Ornamental Seed Pods Organic Burgess Buttercup Winter Squash Cucurbita maxima non GMO Seeds Epimedium Xera Plants