This close-up view makes the flowers seem larger than they are: flowers are diminutive.
image by Wouter Hagens/Wikimedia.org
The perennial heath pearlwort---Sagina subulata---creates a carpet-like groundcover, producing small---about 4 or 5 millimeters (less than 1/4 inch)---white flowers at the end of spring and in summer, a welcome sight when planted in rock gardens and crevices between stepping stones.
An evergreen, heath pearlwort's small-leaved, emerald-green foliage is also welcome in winter. A cultivar called Aurea has golden leaves. As might be inferred from the "heath" part of this plant's name, Sagina subulata isn't finicky about soil. Soil with a pH of about 5 to 7 will suffice.
Buy potted pearlwort in small containers from your trusted plant source. You can buy a flat of such pots if you have a lot of ground to cover.
Dig holes in a sunny or largely sunny area. Space holes 9 inches (22 centimeters) apart and dig about 2 inches (about 5 centimeters) deep, just enough to set the roots entirely beneath the surface.
Remove each plant from its pot as you are about to plant it.
Place each specimen into the prepared holes and cover the roots with soil, pushing the soil down so the plant is secure.
Water the plants well, but don't leave the ground soggy---they're not marsh plants, after all.
Avoid walking on the plants until they are established.
Water regularly. The plant doesn't like to be flooded, nor does it like to dry out. Brown patches mean the pearlwort isn't receiving enough moisture.
Propagate by dividing an established plant and its root, pulling a clump apart into smaller pieces. Divide in autumn or early spring.
Plant the divisions by the same method you used to establish the heath pearlwort at the start.