Prostrate shrubs are used in
horticulture as
groundcovers and in
hanging baskets, and to bind soils and prevent
erosion in remedial
landscaping. They are also important components of
rock gardens. The shrinking size of
urban gardens has meant an increase in demand for and desirability of dwarf and prostrate forms of many garden plants. More recently, prostrate shrubs have received attention for their usefulness in planting
green roofs and
green walls, where they can contribute to
environmental conservation. Prostrate plant forms may arise from deliberate breeding and hybridisation, such as the groundcover
grevilleas, including
Grevillea "Poorinda Royal Mantle", and
G. "Bronze Rambler", or by selection of forms of plants growing in exposed areas. The windswept coastal heathlands and cliffs of far southeastern New South Wales have yielded
Banksia 'Roller Coaster' and
Banksia 'Pygmy Possum'. These are flattened varieties of less than 0.5 m in height of the species
Banksia integrifolia and
Banksia serrata, respectively, both of which grow to sizeable trees of 10 m (30 ft) or more in height.
Species Many
species of roses grow as long canes that can spread prostrate on the ground, and some of these have been hybridized to form
climbing and rambling roses that can be allowed to grow on the ground without support, as well as varieties known as "
carpet roses" that are intended to be grown as ground covers. Prostrate juniper,
Juniperus communis subsp. alpina is a naturally occurring form of a popular
evergreen. Many species of
Cotoneaster, such as
C. apiculatus, are prostrate ornamentals, as are the closely related
Pyracanthas, and the
humilis variant of sweetbox,
Sarcococca hookeriana var.
humilis. Heaths (
Erica carnea and related species) and heathers (
Calluna vulgaris) are prostrate shrubs often featured prominently in rock gardens. Wintergreens such as
Gaultheria humifusa and
Gaultheria procumbens are also prostrate growers. Although, strictly speaking, herbaceous, the North American bunchberry (
Cornus canadensis), a member of the
dogwood genus, can appear as a prostrate shrub when growing in the garden. Many
daphnes, particularly those derived from
Daphne odora, are prostrate growers, including forms that are highly fragrant and have variegated leaves, although they are short-lived. Some forms of the culinary
herb rosemary (
Rosmarinus officinalis) form prostrate shrubs when grown in
Mediterranean climates, although they die back to the ground when grown where winters are colder. ==See also==