by Joan L. Faust • Summer/Fall 1999 (Volume 27, no. 2)
More than thirty years ago the noted landscape architect, Ian McHarg, published Design with Nature, a profound volume that urged least-social cost development and started plantsmen thinking that there was something to the science of ecological principles when it came to choosing plants. His very readable book started fresh thinking in the landscape profession, even changing directions.
Today the nursery industry is scurrying to make native plants available for landscaping. So many native shrubs are worthy of inclusion that the list is difficult to hone down. Here are a few that deserve closer attention:
1. Kalmia latifolia. How wise of our state, and Pennsylvania, to choose the Mountain Laurel as its state flower. This is indeed a glorious shrub that brightens the oak forest in mid-June The genus name honors the Swedish botanist, Peter Kalm, who was a student of Linnaeus. After Kalm's explorations in America, he returned home with many species of "new" plants, one of them this handsome shrub. Linnaeus honored his tireless plant explorer by naming the genus after him.
A member of the Heath Family (Ericaceae), it shows a preference for acid soil. It is often an understory plant, where its evergreen foliage illuminates the setting. When the Mountain Laurel blooms its flowers are worth a close look. Not only are its lovely clusters beautiful, but individually, the flowers have a most special characteristic. The five-sided flowers open wide to reveal small pouches, at the base of which the anthers are attached. When ripe, the anther filaments spring free and release their pollen on the stigma. Bees often initiate this springing action, and you can also do so with a pencil. Incidentally, to promote fine bloom the following year, snap off the faded blossoms, sticky as they are. This halts formation of seed pods and promotes flower bud formation.
2. Lindera benzoin. This quiet bloomer, the Spicebush, has tiny, slightly yellow blossoms which come out before the leaves, as soon as Spring is warm enough to invite hiking. It then gives a golden glow to the understory of the Red Maple swamps it mostly occupies. Eventually the leaves unfurl, and if crushed they emit that wonderful spicy odor which reminds us that, like Sassafras, it belongs to the Lauraceae. It transplants easily and is shade-tolerant. It even has fall berries that wildlife enjoy.
3. Clethra alnifolia. Also a Heath, the Sweet Pepperbush deserves more use in our plantings. A frequenter of wet soils, it does not "come alive" until July or so. It is popular for its ability to form wide thickets because of its stoloniferous habit. This shrub is so fragrant that it can be detected some distance off when its spike of white flowers open. Like Spicebush, it normally grows in wet sites, but it will thrive in most soils if you will water it adequately during dry spells.
We can discuss other species later, but remember that the more we appreciate and utilize these native shrubs, the more the nursery trade will make them available. As another noted landscape architect -- Darrel G. Morrison -- said, this is one way to "protect diversity in the human-dominated landscape."
Winter, 2001 (Vol. 28, no. 4)
Where would our woodlands be without the Viburnums? It is easy to agree with Dr. Michael Dirr that "A garden without a Viburnum is akin to a life without music and art". Although there are many fine introduced cultivars, for those of us who would rather be strictly native, there are three outstanding Viburnums that deserve attention. These are V. dentatum, V. lentago, and V. trilobum.
Viburnum dentatum (Arrowwood) may be dubbed the workhorse of the clan. This is a big shrub that serves well as a property definer or hedge. The white flowers are not huge, and the blue-black berries do not last long once the birds find them. Nonetheless, the handsome deeply-toothed leaves, provide a thick screen.
Viburnum lentago, usually called Nannyberry, is also a big shrub. It grows best in an open, airy location, since this wards off mildew. But it is so carefree that it thrives easily. Again, this is an ideal border shrub and one to attract birds, since its blue-black berries are relished by all our winged visitors.
Viburnum trilobum is always popular, especially in the fall, because of its fine crop of red berries. This is probably why it is often referred to as Highbush Cranberry. In May the white flowers are handsome as well, suggesting the elegant lace cap hydrangeas.
As for hydrangeas, we can hardly comment without including another fine native shrub, the Oakleaf Hydrangea, Hydrangea quercifolia. This is one that seems to have everything. Its long, handsome panicles of creamy-white flowers are held upright. When these fade later in the season, the leaves assume glorious fall colors, mostly in purplish-red tones. Overall, the shrub has a handsome form, about six feet in height, with broad spread. It is most common in the southern deciduous woodland, in Georgia and northern Florida.
Finally, there is Leucothoe, one of our finest evergreens, but not often seen. This one deserves more praise because it appears to be one of the few plants that deer do not nibble. Its tendency to grow in graceful bowers makes it especially attractive. Many times, landscapers choose it as a face-down plant to trim off plantings of rhododendrons and other bulky evergreens.