How to Grow a Shade Garden
Shade is a challenging place to garden, right? I’d say not at all, contrary to some opinions. It is certainly challenging if you expect to grow turfgrass, or plants that require full sun, and it can be challenging if you aren’t cognizant of how shade impacts cultural needs.
Finding a good selection of plants that flourish in shade is no longer a big issue, as the array of exciting offerings has exploded in recent years. Adjust to the idea that the shade garden is a more subtle composition that need not rely heavily on bright color. Though there are selections that offer satisfying pops of vivid seasonal color, the mainstay of the composition will be combining textures and forms for excitement. Imagine frilly textures of ferns arching over mounds of bold leaves of hellebore or hosta, understoried by variegated ajuga. Compose layers of shade-adapted plants, such as Japanese maples or cold, hardy camellias rising above hydrangeas, skirted by perennials, some evergreen, that provide a succession of flowering. Save a few openings for warm season additions such as caladium, torenia or begonia.
Keep in mind that darkly hued plants can virtually disappear in shade. Golden or variegated plants stand out, and those darker plants can be enhanced by using these luminous plants as contrasting background. The popularity of plants with colorful and exciting foliage has increased the number of selections in today’s garden center, in both woody and herbaceous realms. An excellent performer in Tennessee gardens is a cultivar of large shrubby anise-tree, called “Florida Sunshine,” that glows with golden foliage year round. It is key to know what is well adapted to your region, and sometimes it boils down to remarkable specifics.
A good example is the group of shade-adapted, mostly evergreen perennial plants known as coral bells, though the genus name Heuchera (pronounced YOU-kuh-rah) has grown familiar to most gardeners. The Heuchera of old is a mounding plant with attractive green foliage that sends up tall airy spikes of rosy flowers in late spring. Several years ago, cultivars with wine-colored foliage began to be offered, followed shortly by many other forms with leaves of chartreuse, shiny black or marbled purple. These gorgeous plants leapt into the arms of eager shoppers, were lovingly planted, and soon perished in Southern gardens. Cognizant breeders began using a more heat-tolerant species in the genetic mix, resulting in a number of fine forms that stand up beautifully to heat and humidity. “Caramel” and “Citronelle” were early standouts in these efforts, and now there are many more, such as a couple of personal favorites, “Delta Dawn” and “Forever Purple.”
Hellebores are another herbaceous perennial that prosper in dry shade, offering evergreen foliage and winter flowers. Once considered scarce in the green trade, they are now commonly offered and again, knowledgeable gardeners have grown comfortable with the Latin name instead of the common names of Christmas, or Lenten rose. Common forms sport flowers of delicate beauty, but the blossoms nod among the foliage and must be lifted to show their beautiful faces to the gardener. Breeders set to work again, and now there are several selections that hold their flowers proud and high. The Gold Coin series is just one of these new showoff groups.
As with any garden, think seasonally. Fading hellebores can be succeeded in spring by columbine, Virginia bluebells and woodland phlox. By late spring and early summer, the fresh foliage of ferns, hosta and heuchera show off, though hydrangeas will soon steal the show. As summer wanes, Japanese anemone and toad lily offer fascinating flowers that can carry into the days of glorious fall color of shade-adapted shrubs such as Virginia sweetspire, oakleaf hydrangea and spicebush. Winter-flowering shrubs are especially appreciated, so look for winter jasmine and wintersweet along with those cold hardy camellias and hellebores already mentioned.
Dealing with competition from tree roots is a good example of adjusting cultural needs for success. In a wild setting, leaves lie where they fall each year, and decompose in place, creating an ever-renewing root environment of fluffy, humus soil. This nutrient-rich soil stays cooler, promotes good air exchange and does a good job of retaining moisture as compared to mineral soils. The gardener can mimic nature by adding a light layer of compost before planting the shade garden, followed by a yearly application of bark mulch that will continue to improve the soil as it breaks down. Good air exchange is essential for success of most plants, so don’t make the mistake of putting several inches of heavy topsoil under trees, which will “smother” the roots.
Adequate moisture is also key during establishment. There can be no recipe approach for exactly how much to water, as needs will change as day length waxes and wanes and as plants become established. Stick your finger down through the mulch to test for moisture and water generously as it begins to dry, but before it is bone dry. Remember that too much water will kill most plants as effectively as too little.
Difficult? Au contraire! Attention to details, proper plant selections and imitating nature will add up to a lower-maintenance garden than one in the sun. It can be a refreshing oasis, especially in the heat of summer, when hot sun might otherwise drive the gardener indoors.