Rock Mat

Rock mat is a low, prostrate subshrub native to the western and central United States and northeastern Mexico. Its compact, mat-forming growth suits rock gardens and crevices, where it produces small creamy-white flowers in summer. [Denver Botanic Gardens](https://navigate.botanicgardens.org/weboi/oecgi2.exe/INET_ECM_DispPl?DETAIL=1&NAMENUM=8529&refreshlist=1&startpage=0) [Kew Plants of the World Online](https://powo.science.kew.org/taxon/191242-2) ## Growing conditions Plant in full sun or partial shade in a well-drained, rocky site. The Denver Botanic Gardens profile lists this plant for USDA zone 3 and describes a prostrate subshrub with flowers from July through September. Its low, spreading mat can cover roughly 2–3 feet, and the catalog size range is expressed in inches. [Denver Botanic Gardens](https://navigate.botanicgardens.org/weboi/oecgi2.exe/INET_ECM_DispPl?DETAIL=1&NAMENUM=8529&refreshlist=1&startpage=0) ## Landscape use Use it to soften rock edges, crevices, or a small, sharply drained slope. Its low habit makes it a useful contrast to upright alpine and rock-garden plants. ## Maintenance Keep competing growth from covering the mat and avoid sites where water remains around the roots.