This article has been reprinted as part of The Rewind where ELA’s publication chair selects articles from the ELA archives that she thinks will excite today’s readers. This article was originally published in the Fall/Winter of 1998-1999.
Native Shrubs for the Winter Garden
by Cheryl Lowe
“Why are the woods so beautiful in winter, and our gardens are not?” I’ve been asked more than once. I think about this question as I walk in the woods, through neighborhoods near work and home, and through Garden in the Woods (GITW).
What makes a winter landscape special? First of all, the quality of the light is different – softer, quieter, highlighting textures and colors of bark and leaf that are usually hidden by foliage or shade. Snow also plays a major role – accentuating colors, enhancing reflections, intensifying shadows, and turning the contours of the landscape into smooth undulating sweeps. The white of the snow and the low angle of the sun alters our perception of plants and structures in the landscape – highlighting the red-purple hues in evergreen leaves, the delicate golden strands of grasses in a meadow, or the rough textures of a stone wall. By consciously manipulating contours, plants, and structures in our gardens, we can create a landscape lovely in all seasons. One place to start is with shrubs.
Planting for winter interest is not a new subject. Much has been written about the multi-colored exfoliating bark of Acer griseum and Betula nigra `Heritage’, the brilliant red berries of Ilex verticillata, and the rich dark greens of pine or fir. Here are a few perhaps lesser-known native shrubs you might want to try.
Leucothoe fontanesiana (Drooping Leucothoe) is common in the trade, but Leucothoe axillaris (Coast Leucothoe) is a more compact plant better suited for smaller spaces. The glossy, leathery leaves stay evergreen, turning red-green to maroon-purple through the winter. Dense clusters of white, urn-shaped flowers are shorter than L. fontanesiana. Although native to wet woods on the southeastern U.S. coastal plain and rated “Zone 7?” by Hortus III, it grows happily at Garden in
the Woods (Zone 5b) in part shade and well-drained soils. We have L. axillaris `Scarletta’ which shows beautiful red stems through the winter.
Sources: Sylvan Nursery (MA), Roslyn Nursery (NY), Bald Hill Nurseries (RI), Greer Garden (OR)
The glossy bronze-purple winter coloration and small fine texture of Pachistima canbyi (Canby Pachistima) makes it a prime candidate for winter gardens. Forming a low 1 to 2 foot mat of small leathery evergreen leaves, this species starts out light green in spring, turning dark green in summer, then bronze-purple through the winter. Flowers and fruits are inconspicuous. Native to steep, rocky, wooded slopes of the central Appalachian Mountains, it prefers mesic to mesic-dry soils and tolerates shade. We grow it at Garden in the Woods in well-drained soils in half-day sun. It is sensitive to soil compaction, but transplants well. Hardiness to Zone 4b.
Sources: Sylvan Nursery (MA), Siskiyou Rare Plant Nursery (OR), Forest Farm (OR), Twombly Nursery (CT), Appalachian Garden (PA)
Zenobia pulverulenta (Zenobia) is another species that should be more widely grown. The spreading branches with exfoliating red to red-brown bark form a soft 3 to 6 foot mound of fairly dense foliage. The smooth, elliptical semi-evergreen leaves are bluish green (some almost gray-blue), changing in the fall to soft rose-deep purple. At Garden in the Woods many of the leaves hold that soft rose color into February. Flowers are small white nodding bells, like other ericaceous species. Zenobia is a southeastern native found in bogs, swamps, and wooded glades, and is therefore good in moist soils. Although tolerant of some shade, plants grown in New England do better with more sun. It grows well in soils of average moisture, is resistant to heat, drought, soil compaction, and salt, with has few disease or insect problems. Hardy to Zone 5b (GITW) or colder, and transplants well. Periodic pruning is helpful, as vigorous young foliage has the best color and the plants tend to get ungainly if growth is left unchecked.
Sources: Woodlanders (SC), F.W. Schumacker (MA), Roslyn Nursery (NY), Bovees Nursery (OR)
Clethra acuminata (Mt. Summersweet) has beautiful reddish-brown exfoliating bark that makes it stand out against the white snow of winter. The large ovate-lanceolate leaves have a cool medium green color through summer, turning yellow to orange in fall before dropping in October. The fragrant white flower clusters resemble C. alnifolia, but the racemes are longer and somewhat drooping – a magnet for summer butterflies and hummingbirds. The nursery manager at Garden in the Woods, Bill Cullina, was very impressed when he first saw this species in the wild near Asheville, North Carolina. It forms open stands along floodplains of mountain streams and the bark color is stunning to see. Books give this shrub a USDA Zone 6a hardiness rating, but, again, it grows well at Garden in the Woods (Zone 5b). This shrub is very resistant to pests and diseases, tolerant of salt and drought, and seems adaptable to all but excessively dry soils.
Sources: Sylvan Nursery (MA), Twombly (CT), Roslyn Nursery (NY), Woodlanders (SC)
Another shrub with red-brown to deep purple bark exfoliating into papery sheets is Hypericum frondosum (Golden St. Johnswort). A small, fine-textured, deciduous shrub (2 to 4 feet) with upright, spreading two-winged stems, the foliage emerges a lovely
blue-green and remains this color until after flowering, turning green and finally yellow in fall. The half-inch wide golden flowers bloom in July with numerous bright yellow stamens that give them a powder puff appearance. The reddish-brown to maroon-purple, half-inch fruit capsules persist, adding winter interest and providing food for songbirds. Native to the uplands of the southeastern U.S., it prefers full sun and well drained to dry soils. Although native to alkaline soils, it seems to have no problems with acidity. Rated Zone 6a, but hardy at Garden in the Woods and colder. It is resistant to salt, drought, and heat, with few disease problems. The cultivar `Sunburst’ is most often available and has much larger flowers.
Sources: Sylvan Nursery (MA), Niche Gardens (NC), Forest Farm (OR), Daystar (ME)
*Cheryl Lowe is the Director of Horticulture for the New England Wild Flower Society and a past member of the ELA Board of Directors.
Fall and Winter Fruit for Birds
by Nick Novick
A number of plants have visual qualities which provide us with aesthetic interest in the fall and winter landscape. Some inter- esting, and possibly unfamiliar ones are described in the accompanying article. Plants especially berry-producing trees and shrubs and seed-producing perennials, can also be an important food source for birds at this time of year.
While it is widely known that many songbirds eat wild berries in the autumn, a recent study on Block Island, off the coast of Rhode Island, documented for the first time just how important this food source is. The study lead by Dr. Jeffrey Parrish, indicated that autumn wild berries provided from 70 to nearly 100 percent of the diets of a number of migrating song birds, even though many of these birds rely on insects during the summer months, and even though insects were available during the fall.
Birds such as the gray catbird, hermit thrush, rufous-sided towhee, red-eyed vireo, yellow- rumped warbler, and rose- breasted grosbeak tended to flock to plots, some relatively small, that were “thick and fruity” in the words of Parrish, while mostly avoiding test plots where researchers had removed the fruit. Birds would spend up to a week or longer over a period from early August to early November building their fat stores for migrations of up to 5,000 miles to Central and South America.
Such information emphasizes the need to preserve wild areas and should encourage us to provide food sources for our feathered friends and other wildlife. The same plants are
often visually engaging for us as well. There are many plants which fill this role, a few possibilities are mentioned below.
Myrica pensylvanica (Bayberry or Wax Myrtle) Deciduous shrub with small grayish-white berries; if în thickets, also provides cover. Does best on open sites with full sun, tolerates poor, acid, sandy soil. Can reach 5 to 10 feet in height.
Sorbus spp. (Mountain Ash) – S. americanus, the eastern North American species, is a small tree/large shrub of northern latitudes; needs cool, mulched root zone and acid soil. Somewhat fern-like, pinnately compound leaves are among the showiest in fall. Flame-red fruits persisting through winter are a valuable food source.
Cornus spp. (Dogwoods) All except for the Asian C. kousa produce fruits that are valued by birds. C. drummondi (Roughleaf Dogwood) tolerates dryer sites than its relatives, tends to thicket, and produces white fruits with bright red stalks. C. alterniflora (Pagoda Dogwood) does well in deeper shade and produces blue bernes that ripen early. C. florida (Flowering Dogwood) is perhaps the best known, is widely adapted through Zone 5, and has bright red fruits. Investigate the many other members of the Cornus group.
Viburnum spp. – As a whole, this is a great group for foliage, form, and flower as well as fruit, but take note that often the varieties with the largest, showiest flowers don’t bear fruit heavily. The fertile berry- producing flowers tend to be the small, inconspicuous ones at the center of the inflorescence.
llex spp. (Hollies, both evergreen and deciduous) – I verticillata (Winterberry), a large deciduous shrub, likes wetter areas and holds bright red berries until spring if the birds don’t get them. I. glabra (Inkberry) is evergreen with small leaves and a handsome bushy habit producing small indigo/black berries. To produce berries, female plants need to have at least one male plant in close proximity.
Some of the many other plants useful to birds include: Phytolacca americana (Poke Weed), Sambucus canadensis (American Elderberry), Amelanchier spp. (Serviceberry or Shadbush), Lindera benzoin (Spicebush), Malus spp (crabapples and apples), Crataegus spp. (Hawthorns), and Rosa spp. (Roses). Seeds from certain perennials such as Echinacea spp. (Coneflower), Solidago spp. (goldenrods), Aster spp., and Helianthus spp. (sunflowers) will also be utilized.
Sources used for this article:
Migrating songbirds switch their diets for long trips south, New York Times, Tuesday, November 18 1997.
Noah’s Garden, Sara Stein. Houghton Mifflin, 1993.
Landscaping with Native Trees, Guy Sternberg, Jim Wilson, Chapters Publishing, 1995
(Thanks to Jennifer Pettit who provided information for this article.)
*This article was originally published in ELA’s The Ecological Landscaper in the Winter of 1998-1999