Lavandula dentata. Evergreen perennial herb with finely cut, aromatic, silver grey foliage. Spikes of fragrant purple flowers in summer. Prune back in early spring or late fall. Attracts butterflies. Good in herb gardens, borders, containers, and rock gardens. Grows 18-24" tall and wide. Full sun. Plant in light, well-drained soil. Zones 5-9.