Liatris spicata 'Kobold' 'Kobold' Spike Gayfeather Size: 2 to 4' high by 18 to 24" wide. Hardiness: Zones 3 to 9. Heat Zones: 9 to 1. Habit: They produce dense tufts of narrow, grasslike basal leaves followed by tall, upright flower spikes of rose-purple flowers. Culture: Full Sun to light shade.