|Thymus serpyllum is a low growing, mat forming hebaceous perrenial or sub shrub. Foliage is a medium green, to grayish blue, even yellowish depending on the cultivar. Tiny flowers are purple, bloom through summer, really attract bees. Prefers dry, calcareous soil, and sun. If over fertilized it becomes weak and twiggy. Plant it in sidewalk cracks, overhanging on rock walls, or as a good groundcover around stepping stones. Native to Europe, Asia, northern Africa. Various cultivars have been developed.