Veronicastrum virginicum Culver's Physic Description Elegant white flower spires bloom from July to August. The whorled leaves present strong horizontal lines, while the flower spikes provide vertical accents. Native. Sizes & Prices All Culver's Root Characteristics Hardiness Zone: 3-8 Light requirements: Sun/Part Sun Height: 3-6' Native: Yes Sizes & Prices Size: 2 Yr $12.98 Other Information Culver's Root Veronicastrum vir. 'Lavender Towers' Zone: 3-10 Sun/Part Sun HT: 4-5' Culver's Physic Veronicastrum virginicum Zone: 3-8 Sun/Part Sun HT: 3-6'