Rock Gardening With Native Plants

ROCK GARDENING WITH NATIVE PLANTS

By

Frank W. Porter

Porterbrook Native Plants

Rock gardening is a highly specialized way of gardening with plants normally adapted to high altitude growing conditions. It was at one time the preserve of wealthy landowners, especially in England, who had the means not only to create rock gardens but enough influence to gain access to the rare and difficult to grow species to plant in them. Plant collectors searched far and wide to satisfy the demand for these plants. It was not long before gardeners in the United States joined in this rock gardening mania. Specialized nurseries came into existence, offering rare and unusual species from every continent.


The creation of the North American Rock Garden Society in 1934 made it possible for more gardeners to enjoy this unique hobby. In recent years, rock gardening has once again grown in popularity. While enthusiasts continue to search the globe for plants to add to their collections, many aficionados are surprised to learn that there are beautiful native species growing in the Ohio Valley perfectly suited to use in rock gardens.


Constructing a rock garden does not necessarily have to be an expensive or labor- intensive endeavor. One sure way to ensure success is to start small and learn through trial and error. There are six important steps to follow: plan carefully; prepare the site; be prepared to move the stones; set the stones in position; make up and use the planting mixture; and select the plants and proper mulch.
Another way to enjoy rock gardening is to use troughs, more commonly known as hypatufa containers. Hypatufa containers are planters for alpine species and diminutive plants. Hypatufa is a mixture of Portland cement with peat moss and perlite. It is much lighter than concrete. Growing plants in troughs allows one to cater to the individual needs of different species and to grow many more plants in a restricted space. It also brings you into close proximity with your plants. Imagine, also, the ease of weeding, watering and controlling pests.


What to grow? There are a surprisingly large number of native plants from our region that suitable for use in rock gardens or hypatufa containers. Three species of Sedums are essential to any rock garden. Sedum ternatum (Wild Stonecrop) is a low, sprawling perennial that grows on rocks, logs, or even bare soil and prefers dappled shade. It possesses small fleshy leaves and attractive starry white flowers. Sedum telephoides (Allegheny Stonecrop) enjoys full sun and humus-rich sandy soil. It has glaucous leaves and pink starry flowers in flat-topped clusters. Sedum glaucophyllum (Cliff Stonecrop) prefers partial sun and well-drained gravelly or shaley soil. It forms an extensive mat of compact rosettes of gray-green fleshy leaves resembling pinwheels. Numerous white four-petaled flowers sparkle above the foliage.


Native Irises add an attractive element to the rock garden. Iris cristata (Dwarf Crested Iris), found in partial shade and growing in rich, well-drained soil, reaches about six inches in height. Beautiful three-inch blue flowers with a golden crest, nestle among the arching leaf blades. Iris verna (Dwarf Iris) grows in sandy or rocky open woods. It has straight, narrow, bright green leaves which reach six inches in height. The showy, lavender flowers, however, do not possess the crest.
Pussytoes, whose name refers to the resemblance of the flower heads to cats’ paws, make a welcome addition to the rock garden. Antennaria virginica (Shale-barren Pussytoes) thrives in full sun to partial shade with poor shaley or sandy soil. This low spreading plant forms attractive colonies of silvery rosettes with fuzzy, white flowers. Antennaria plantaginifolia (Plantainleaf Pussytoes) can withstand very dry soils. The leaves are pale green above and woolly beneath. The flowers are white or purplish.


Phlox subulata (Moss Pink) is densely matted with semi-evergreen, awl-shaped leaves. The flowers range from pink to rose-purple to white and possess a dark eye. It prefers dry, rocky habitats in full sun. Phlox stolonifera (Creeping Phlox), which prefers moist woods, has trailing stems that can root at the nodes. The flowers range from bluish to rose-purple.
Paronychia argyrocoma (Silverling) grows on open rocky slopes, outcrops or ledges and forms mats or tufts. The numerous silky-hairy stems hide small white flowers that grow at the top of the stem.
Meehania cordata (Meehania) is a trailing plant that requires shade and grows in moist humus soil. Its heart-shaped leaves and pale blue, one-inch flowers will enhance any rock garden slope.


No rock garden should be without examples of native grasses and sedges. Danthonia spicata (Poverty Grass) is a denizen of dry woods. Reaching only four inches in height, its foliage remains green during the winter months. Luzula acuminata (Hairy Woodrush) grows in partial shade with average soil. Its grass-like leaves are adorned with wispy, white hairs. Luzula multiflora (Common Woodrush) can withstand full sun. Its leaves are a beautiful reddish brown. Carex flaccosperma (Blue Wood Sedge) highlights a winter day with its blue foliage. Carex platyphylla (Silver Sedge) likes dry, dappled shade. Its silvery green leaves stand out beside rocks partially buried in the garden.


The list of native plants suitable for rock gardens or hypatufa containers is extensive and varied. Gardeners interested in learning more about using native plants in rock gardens are invited to contact me at the email address below. Joining the Ohio Valley Chapter of the North American Rock Garden Society should be on your list of New Year’s resolutions.


This article was first published by the Marietta Register