Cerastium (ser-rass-tee-um); Mouse-ear chickweed, Pink Family (Caryophyllaceae). Cerastium is a large genus of low-growing, hardy and practically ineradicable perennials. Any sandy or ordinary well-drained soil and full sun are the only requirements. C. tomentosum (toh-men-toh-sum) Snow-In-Summer is native to Europe, grows to 3 to 6 inches high mat of small gray leaves and dainty, white tubular flowers.
Cerastium should be planted in full sun and poor, well-drained soil. When grown in moist, rich soil, it will spread very rapidly and be hard to contain. The foliage should be trimmed back after the plant is finished blooming to promote more compact growth. It may divided any time during the growing season.