Alpines and Other Rock Garden Plants
Alpines and other rock garden plants are characteristically compact and neat, and as such are particular suited to the smaller, modern garden. Their diminutive size allows the gardener to grow a wide variety of species and hybrids within a relatively small space.
Rock Garden Plants
As their name suggests, these plants are particularly suited for growing in rock gardens. They consist of any slow-growing species of relatively small stature, including dwarf shrubs and trees. Whilst they do not necessarily come from alpine regions (in fact, many of the plants come from coastal or Mediterranean areas), they share the alpines' need for a free-draining soil, which makes them suitable for planting together.
Most true alpines flower in the spring and early summer, so late-blooming rock garden plants can be chosen to extend the season of interest.
True Alpines
Alpines tend to be very compact, with few over 15 cm (6 in) tall; their low-growing habit reduces their wind resistance and helps them to protect themselves against the heavy snow of winter. Their small, hairy, fleshy or leathery leaves and their mat- or cushion-forming habit also helps them to minimise moisture loss in hot sun and high winds. Most have extensive root systems designed to seek out moisture and nutrients in the thin, poor soils of their native habitats.
Alpines are characteristically hardy as they have adapted to survive in high altitudes and extremes of climate. They are deciduous or ever-green woody plants; they can also grow from bulbs or be herbaceous.
Whilst alpines have evolved to withstand extremes of temperature, they dislike warm, humid, summer conditions or constant wetness at the roots.
Alpines for Beginners
There are many alpines that are undemanding and so may be grown easily in the open garden. They produce a variety of effects; from spreading mat- and mound-forming plants to tiny cushion- formers. A number of species consistently produce a wealth of blooms, flowering well into summer. Try low-growing cultivars of Aubrieta or phlox; they produce carpets of bright colour which are particularly effective in softening any harsh planting edges.
Alpines for Experts
Whilst there are many alpines that are relatively simple to grow, there are a number of species that have very particular requirements. The majority of these plants need extremely free-draining soil and protection from constant wetness during the winter (e.g. Saxifraga 'Suendermannii'). Most will require plenty of sun, although their roots should be kept cool. Woodland plants usually prefer dappled shade and may need moist, acid soil.
A good way of dealing with these plants is to take them out of the ground and plant them in raised beds or containers such as troughs or sinks, using gritty, free-draining soil or composts. Rock gardens and wall crevices are a great place to plant species that need a sheltered spot and a cool root run, as it provides them with the ideal conditions and displays them to their best advantage in natural-looking surroundings.