What's the Best Seed for Overseeding Your Lawn? Lawnbright 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 Kale Seed Planting Unlock the Exciting World of Growing Succulents in Water Choosing the Best Plant Pots for Your Home and Garden The Balcony Garden Bridal bouquet with succulents.