Rock Garden The rock garden represents one of the harshest environments on the planet. A high mountain habitat, naturally occurring when rocky outcrops erode to create slopes of fallen rock and shingle. In the wild, alpine species of plants are adapted to thrive in these inhospitable areas. Growing in virtually no soil, they often form a long tap root that can reach down several metres for anchorage and to find a water source. Above ground cushions or mounds are formed of tightly arranged leaves, under which, each previous seasons growth creates a layer of decaying leaf matter, providing essential food for the plant. Spring is the best time to see the scree as many alpine plants will burst into flower when the snow melts and the short growing season begins. The earliest spring flowers you can see here are the Saxifraga species.