Selected cultivar of Arenaria montana L., from the Caryophyllaceae family, 'Avalanche' is a horticultural form derived from the wild species found in southwestern Europe. It was selected for its exceptional flowering generosity and particularly dense and covering habit.
It forms a more compact and regular carpet than the type species, with prostrate and branched stems, adorned with oval-lanceolate leaves of a medium green slightly pubescent. The tuft remains low, between 5 and 10 cm in height, and gradually spreads to form a homogeneous and tight ground cover.
The flowers are white, with five broadly oval and entire petals, of good size, produced in remarkable quantity to the point of completely masking the foliage at full bloom. It is precisely this mass effect, evoking a snow flow on the rock garden, that inspired the cultivar's name. In cultivation, flowering generally occurs from April to June, sometimes earlier in regions with mild winters, with a possibility of partial reblooming in autumn under good conditions.
Like the type species, 'Avalanche' prefers full sun, well-drained soil, slightly acidic to neutral, without excess winter moisture. It is suitable for rock gardens, walls, borders, and containers, and tolerates light pruning after flowering to maintain a compact habit.