Saxifraga stolonifera aka Mother Of Thousands

Saxifraga stolonifera is a compact, low-growing perennial that typically reaches 15-46 cm (6-18 inches) tall and spreads 30-60 cm (12-24 inches) wide. It increases rapidly by producing long, thread-like red stolons that bear plantlets at their tips, allowing a single plant to form a dense groundcover within a season or two.

The plant is cold-hardy to approximately -10°C (14°F) when dormant and is generally rated to USDA Zones 6-9 (some sources extend it to Zone 5, UK hardiness zone 5). The semi-evergreen leaves and developing flowers are vulnerable to autumn frosts, so a sheltered position and winter mulch are recommended at the cold edge of its range.

From late spring through summer, Saxifraga stolonifera throws up airy panicles 20-46 cm tall carrying 7-60 small white flowers. Each flower is asymmetric with five petals — two large lower petals 6-15 mm long and three much smaller upper petals dotted with red or yellow markings — producing a delicate, almost orchid-like effect.

Outdoors the plant prefers a sheltered position in part to full shade with moist, humus-rich, well-drained soil; it tolerates clay, loam, or sand and a wide pH range. It is hardy to roughly USDA Zone 6 (with mulch in Zone 6 winters) and works well as a groundcover, in rock walls, or along shaded borders. In its native range it grows on shady cliffs and mossy rocks at low altitudes, and it has naturalized on walls in central and southern Europe.

The easiest method is to detach and pot up the small plantlets that form at the tips of the red stolons — they root readily in moist soil. Established clumps can also be lifted and divided in spring, and seed can be surface-sown in a cold frame in spring (keep the compost moist).

Saxifraga stolonifera has no known serious diseases or insect pests in cultivation. Like most foliage plants, it can occasionally suffer from typical houseplant pests such as aphids or mealybugs, but it is generally regarded as trouble-free.

The flowers are zygomorphic with conspicuous white lower petals and contrasting red or yellow nectar guides on the smaller upper petals — a structure typical of insect-pollinated saxifrages.

The leaves and flowering stems are edible. In Japan the foliage is relished parboiled or fried and added to salads, and the flowering stems are said to be tasty when salted. PFAF rates its edibility 2 out of 5.

The plant has a long history in East Asian traditional medicine. It is reported to be antibacterial and antiphlogistic (anti-inflammatory), with the whole plant used as a depurative, febrifuge, and suppurative. Decoctions have been applied to boils, abscesses, snakebites, ear infections, convulsions, and internal bleeding, and fresh leaf juice is used topically on ears and inflammations. It contains quercetin, which has shown anti-cancer activity in vitro. PFAF rates its medicinal use 2 out of 5.

Beyond its ornamental value, the species is most useful as a groundcover for shady positions, where stolon-borne plantlets quickly knit into a dense mat — typical spacing is about 45 cm apart. PFAF rates its other uses 2 out of 5.