Arenaria serpyllifolia, commonly known as thyme-leaf sandwort, is an annual or biennial herb native to Europe, North Africa, and temperate Asia. It typically forms low, dense mats up to 6 inches (15 cm) in height and spreads out to 12 inches (30 cm) wide. Thyme-leaf sandwort thrives in a variety of habitats including grasslands, rocky slopes, and open woodlands, often preferring calcareous soils.

This plant is characterized by its small, oval to lance-shaped leaves and tiny white flowers that bloom from May to July. The flowers are not particularly showy, but they do add a delicate texture to garden settings. Thyme-leaf sandwort is valued for its ability to cover ground quickly, making it useful for rock gardens, between stepping stones, or as a filler in container plantings. It requires well-drained soil, moderate watering, and can grow in full sun to part shade. While it is generally low-maintenance, it can become invasive outside its native range, so gardeners should monitor its spread.CC BY-SA 4.0