1000 CULVERS ROOT (Black Root) Veronicastrum Virginicum Flower Seeds BLOOM TIME: Summer HARDINESS ZONE: 3 - 9 PLANT HEIGHT: 36 - 60" . . . PLANT SPACING: 15 - 18" LIGHT REQUIREMENTS: Sun - Part Shade . . . SOIL / WATER: Average - Dry The lovely flower spikes similar to Veronica or Verbascum attract bees, birds, and butterflies.