
The name is somewhat of a mystery. It is related to neither lavender nor cotton, but Santolina chamaecyparissus is known as lavender cotton nonetheless. The small, silvery gray leaves have a finely wrinkly texture, and are remarkably aromatic, like lavender. Though, the small and round bright yellow flowers look like daisies with the outer petals plucked off.
Unlike lavender and most other similar evergreen semiherbaceous shrubs, lavender cotton is adaptable to shearing, and is actually a classic component of traditional ‘knot gardens’, usually with another species of Santolina with green foliage to provide contrasting color. (Knot gardens feature small hedges with various foliar colors shorn into geometric and sometimes intricate patterns.) If regularly shorn, it is appreciated for its strikingly gray evergreen foliage, since it will not bloom.
Unshorn plants get about two feet tall and a bit broader, and will eventually need seasonal light shearing to remove fading flowers after bloom. Annual pruning at the end of winter keeps plants compact and neat without depriving them of their bloom. They otherwise eventually get bald in the middle and sloppy around the edges. (Some of us know about that.)
Good warm exposure and well drained soil is best. After their first year, lavender cotton does not need much water.