Saxifraga 'HARDER ZWERG' moss saxifrage
Saxifraga
Saxifraga is one of the most extensive genera of the Northern Hemisphere, comprising more than 400 species distributed from arctic regions to the high mountain ranges of the Himalayas. Most of them inhabit places where other vegetation would struggle to survive – scree slopes, rocky ledges, moist springs or fissures in limestone walls. Their ability to anchor themselves in tiny pockets of soil with just a trace of moisture gave the genus its name: saxum means stone and frangere to break, although saxifrages do not literally break rock; they simply exploit its natural cracks. The genus was described by Carl Linnaeus in 1753, but its internal classification has been revised many times since, as saxifrages are notorious for hybridisation and morphological variability. The botanical species that later became the foundation of garden hybrids originate mainly from European and Asian mountains – for example S. hypnoides, S. rosacea or S. paniculata – and share small rosettes of leaves, five‑petalled flowers and the ability to form dense, low mats in cool, moist habitats.
The hybrid group Saxifraga × arendsii emerged at the turn of the 19th and 20th centuries thanks to the German breeder Georg Arends (1863–1952), who crossed several mountain species to create perennials suited to semi‑shaded gardens and urban rockeries. Arends’s plants quickly gained popularity because they offered something gardens of the time lacked – spring colour, compact growth and the ability to thrive even where the soil is cooler and more humid. Over time, an entire group of hybrids developed, characterised by moss‑like rosettes, delicate flowers in shades of pink, red and white, and reliable spring blooming.
Harder Zwerg is a moss saxifrage forming a compact clump of evergreen, soft green leaves. In mid spring come out short stems with rich carmine red flowers. The plant grows slowly, spreading to sides.
Arends saxifrage hybrids share growing requirements shaped by their mountain origins. They thrive in partial shade or in bright positions protected from harsh midday sun. They need cool, humus‑rich and slightly moist soil that must nevertheless be very well drained – prolonged waterlogging as well as complete drought are their greatest risks. A mixture of garden soil with fine gravel or coarse sand is ideal. During the growing season they need a little bit of watering so that the soil never dries out completely but also never remains wet. Feeding should be minimal, just a light application of compost or a weak fertiliser for rocky plants in spring. After flowering it is advisable to remove the spent flower stalks to maintain a compact shape. In older clumps it is common for the centre to open and brown – a natural growth cycle of the rosettes that accelerates with excess moisture or poor air circulation, so very free‑draining soil and watering at the base rather than over the leaves are essential. They are usually hardy to around −34 °C, ensuring reliable overwintering even in colder regions. Troughs and containers are unsuitable, as they heat up quickly in summer and may become waterlogged in winter, conditions saxifrages tolerate poorly.
Last update 06-04-2012
