Color is often the primary criterion when new gardens are beginning - but a splash of red here, or a pool of blue there, even with pastel punctuations in between, doth not a garden make. It is of course true that color is of major importance in the garden, but as with sculpture, color is never separate from form or texture and is only one leg of that landscape triumvirate. The development of color amongst form and texture can be played out in the garden in as many ways as there are gardeners. While it is frequently easy to find many different plants of varied colors, form and texture are often less advertised attributes, and therefore, developing a palette of form and texture among a range of plants can be more of a challenge. In particular, extremes of form and texture can be hard to find, especially among reasonably priced, low maintenance plants. Two plants that combines low maintenance with an amazing mix of summer and winter texture and form are Aralia spinosa, Devils-walkingstick, and Aralia elata, Japanese Angelica-tree.
Devils-walkingstick, sometimes called Hercules-club, is a coarse-stemmed, large, deciduous shrub with a few main, unbranched stems that grow in a cluster, forming a small stand of itself. It is native to the south-central and southeastern US. The overall appearance is quite fascinating - as if some prehistoric jungle had been miniaturized and set in the landscape. Each thumb-thick stem is covered with large, (and painful!) spines with lengths from 1/2 to 2" on the same stem, the character undoubtedly responsible for its common names. The 10 to 25 foot tall shrub has an overall oval to rounded outline but the texture of individual stems is quite prominent. In winter, the bare, light grey stems create strikingly bold silhouettes. The foliage is large and doubly divided, somewhat like that of Kentucky Coffee Tree (Gymnocladus dioica). The many leaflets of each single leaf are 3 to 4 " long and appear as if they are the individual leaves and a single leaf can be 2 to 3 feet wide The emerald green foliage is very exotic and tropical in appearance and softens the stems' bold character to some degree in the summer. Fall foliar color is often a medium yellow but is very variable and not of primary interest. In mid-summer, masses of tiny, creamy flowers appear held in raised, ladder-like clusters. The flower stalks are quite lovely emerging from the foliage, adding yet another dimension of form and texture. The flowers ripen to purple-black fruits suspended from rose colored stalks and are quite handsome.
Japanese Angelica-tree is very similar to Devils-walkingstick but is perhaps a bit more refined in summer texture and will reach heights of up to 40 feet with time. It is, as the name suggests, native to Japan and Korea and is also somewhat more cold hardy than the American Aralia - growing successfully as far north in the US as the northern mid-west. Unlike A. spinosa, there are beautifully variegated cultivars of A. elata. The leaves of 'Aureo-variegata' have light gold borders, while the foliage of 'Variegata' is splashed with irregular borders of egg-shell white - an especially beautiful form and very refreshing in the summer landscape. The variegated forms are extremely difficult to find in this country as they must be grafted in one of the most difficult procedures involved in propagation of any ornamantal plants.
Both Aralia species are well-adapted to southeastern landscapes. They are hardy from the coast to the mountains and will perform well in sun or partial shade. They prefer moist, well-drained soils but will tolerate the clays of the Piedmont. They are both relatively rapid growers as young plants but growth slows when mature wood develops. A. spinosa, especially, suckers readily and can be an invasive spreader if not controlled by weeding up the suckers. However, this tendency can be an excellent way to develop a boldly textured planting relatively rapidly. Propagation is by seed which requires 2 to 3 months of chilling, or by digging the root suckers. Cuttings taken from the roots themselves will also successfully root and develop shoots.
Both Devils-walkingstick and Japanese Angelica-tree make strong statements in the landscape. Their bold character, ranging from exotic summer foliage to coarse and thorny winter stems, makes them an invaluable addition to any gardener's palette of form and texture. At The NCSU Arboretum (now the JC Raulston Arboretum), Aralia are growing in a number of sites, including the White Garden by the Visitor's Center entrance. Walk through the Arboretum to let Aralia illustrate some of the fascinations of form and texture in the landscape.