Native Wildflowers for Shade
Great choices for low light areas of your garden.
Horticulturist & Plant Records Coordinator
Looking into that gloom-cast corner of the yard, or limb-strewn and flowerless woodland plot, a homeowner may be discouraged to bring these spaces into the heart of the garden. When the local deer clan likes to shelter and graze in these areas, the gardener is further disheartened. Having evolved under a continuous canopy and among the deer that still wander our land, native woodlanders are better prepared than most to meet these challenges and perform superbly.
In discussing the choices and their comparative qualities for planting in shaded and deer-grazed areas, it is best to categorize the several types of conditions found in shade gardening. There is light shade versus deep shade. The trees that create the shade change the terms of planting, often having only shallow interstices among their roots for planting within a certain radius of each tree, and sometimes creating dryness. Although dry shade is common, plants for average soil and those for rich soil in shade also need to be considered.
From the long list of shade-tolerant native perennials, many of the best are found among the asters and ferns. Blue wood aster (Symphyotrichum cordifolium) and white wood aster (Eurybia divaricata) both bloom after much of the summer show, and withstand both shade and dryness as well as being happy in average soil. If you have a horde of rabbits, you might find they have a taste for asters. Whorled aster (Oclemena acuminata), with white stars, prefers moisture, but grows well in many spots that remain dry in late summer. These native asters will seed about their immediate area lightly. After a few years’ growth, multiple crowns will develop, making spring division possible. Irrigation is needed only when establishing new plants or during summer drought.
For moist soil, lady fern (Athyrium felix-femina), including the popular red-stemmed ‘Lady in Red,’ is as comely as could be, whereas hay-scented fern (Dennstaedtia punctilobula) spreads its spring-green readily in drier soil. Give the hay-scented fern tough competition or a barrier to keep it in bounds (such as stonework, gravel trenching, or vertically inserted plastic resin or galvanized steel sheeting a foot or so deep). Christmas fern (Polystichum acrostichoides) is adaptable and brings some green to deep winter. Where the soil is cool and moist, oak fern (Gymnocarpium dryopteris) spreads diminutive fans of elegant spring green as a slow groundcover. You will not likely need to divide these since they spread naturally, but watering needs to be consistent except with hay-scented fern.
Aside from asters and ferns, the vast array of native woodlanders purveys a number of stand-out plants. Wild geranium (G. maculatum), is cheerful, pest-free, and almost too easy to grow. The cultivar ‘Espresso’ has deep brown-purple leaves. Wild bleeding heart (Dicentra eximia) is similarly carefree as long as the soil does not dry in summer, in which case it goes dormant. If so, you will want to pair it up with a late bloomer such as Eupatorium rugosum (syn. Ageratina altissima) ‘Chocolate’ foliage available as well. Geranium and Dicentra will seed about on their own. Wild Blue Phlox (P. divaricata) and Creeping Phlox (P. stolonifera) offer a swarm of blossoms with named selections for a range of color and they quickly volunteer to fill their space. Although these plants are self-propagating, they bloom early and so are prime choices to pair with the later asters.
Statuesque species of black cohosh, or bugbanes (Actaea racemosa, A. americana, A. rubifolia), are not as easy as the preceding choices, but are reliable and rewarding in rich, medium moist soil. Appalachian bugbane (A. rubifolia) is more compact than its siblings with handsome maple-form leaves and a sweet fragrance. Another king of the rich woodland is the umbrella leaf (Diphylleia cymosa), still found mostly in the smaller specialty nursery catalogues (available from New England Wild Flower Society). Dramatic leaves push forth slender stalks of tiny white flowers followed by blue berries on bright red stems almost as eye-catching as the fruit. While it prefers moist soil and part shade, umbrella leaf responded to last summer’s heat and drought by developing a gorgeous burnished copper in its leaves. Red wakerobin (Trillium erectum), beetleweed (Galax urceolata), and Oconee bells (Shortia galacifolia) are all three medium-rate growers in rich, moist, shade and will be the envy of many a garden visitor. These elegant plants take a fair number of years to reach divisible size. Beetleweed and Oconee bells creep about nicely, though. During summer dry spells, you will want to water these thoroughly as well as add a couple of inches of summer mulch, both for nutrition and for moisture retention. In winter, a covering of evergreen boughs will encourage beetleweed and Oconee bells to thrive and spread, as well as fend off deer.
Caring for native woodlanders is different from some of the highly selected and hybridized plants. Most natives will be more pest-resistant and less irrigation-dependent, exceptions noted. If you start with soil that has a high organic content and good loft, you will find that your native woodlanders need little in the way of fertilizer. Especially for the plants that prefer rich, moist soil, you might find a light dressing of slow-release, balanced fertilizer in spring brings out their best. Restraint is in order as too much nitrogen may force out excess tender growth, leaving the plants more vulnerable to both pests and lack of rain. Shallow-rooted choices like the woodland phloxes and bleeding hearts can be tucked into spaces where tree roots infringe.
When it comes to hungry deer, few plants are completely safe. However, of the plants mentioned, only beetleweed has shown itself to be particularly attractive to deer. Although it is a shrub, dog hobble (Leucothoe fontanesiana) and coast leucothoe (L. axillaris) are almost never eaten by deer. In reasonably moist soil with good organic content, these shrubs will share space with tree roots and grow even in deep hemlock shade. Leucothoe is also available in variegated and red-leaved forms (i.e. ‘Girard’s Rainbow,’ ‘Scarletta’). Anti-feedant sprays (such as Bobex) have worked well for me in a number of gardens and areas, but need to be reapplied about every month to remain effective. Fine, black netting can be spread temporarily over emerging plants or wintering shrubs, is not very noticeable at a distance, and it works. This strategy will enable you to grow two other outstanding small shrubs for light shade. Smooth hydrangea (H. arborescens) is fully hardy right down to the flower buds, and so will not disappoint like the hortus and Japanese varieties. Oakleaf hydrangea (H. quercifolia) bears its flowers in extended cones, rather than typical domes, and its foliage competes with the blossoms for attention. Bold oak-like leaves look great all season and turn the richest wine shades in fall with good light. Not to be outdone, the flowers fade through cream and coffee tones to an eventual pink blush. Smooth hydrangea likes average soil and moisture, but will enjoy rich soil, where oakleaf hydrangea will also flourish.
Sometimes perusing an exemplar planting can be worth years of experience in the garden. If you are of a mind to look before you plant, come see the Woodland Garden at Garden in the Woods this spring, where you will see these woodland characters in various combinations and situations. Visit also our informative nursery page at www.newfs.org for more great native shade plant choices. You will come away emboldened and inspired to create your own native woodland haven.