Often our clients assume that a native plant restoration (one aspect of our designs) requires full sun or enough room for a prairie. Yet most urban lots and the places people love to build their homes are either deep woods or savanna (the woodland edge). If not, people plant trees around the structures where we live and work to keep them cool in summer and warmer in winter. Because our ancestors, over the past several hundred thousand years, lived on the edge of the woods with views out into the open country, that is where many people feel safest.
The result is that most home landscapes are either shade or will become shade as those added trees mature. It takes only a few years for even relatively small transplants to form a canopy that promotes more outdoor living than full sun.
It is true that the very first native plant restorations did focus on prairie species. We now have the ability and diversity of native plants available to apply ecologically based design in virtually any habitat. Here in the Upper Midwest these include: open water, margins of lakes, and streams and marshes with wet soil, right on up to dry soil conditions in the full spectrum of sunlight available – from full sun to full shade. We have nurseries that specialize in these different habitats, so that we can purchase native diversity from local seed sources.
Many homeowners might assume that if they are living in deep shade that they must purchase annuals to grow in pots and that they have to add new plants every spring. This is a huge industry, supplying homeowners with the latest tuberous begonias, impatiens in every color of the rainbow, and hosta (from Japan.) You may not realize that we have a native impatiens. It is also an annual, and is also called jewelweed. Noted for its syrupy sap that will sooth poison ivy welts, it is common on rich woodland soil where it stays moist.
There are several trees we recommend for creating the shade people desire around their homes: hackberry, several oak species (red oak grows surprisingly fast,) hickory, basswood, and aspen are all good for quick shade as slower growing species, like sugar maple, take root.
Shrubs for shade vary from diminutive snowberry, coral berry, leatherwood (3-5′ max. ht.), gray dogwood, several species of serviceberry, and wahoo, and also small trees like nanny berry, musclewood/blue beech, and ironwood. These species all provide interesting blooms, fruit for us and birds, striking fall color, beautiful bark/form in winter, and they survive in sites with little to no direct sunlight. Their height is important for many songbirds looking for nest sites. Standard American landscapes with manicured lawns, shrubs, and high tree canopy are missing this intermediate height they prefer for raising the next generation. These song bird populations have plummeted in North America over the past ten years as a more natural areas are turned into homes for people with standard landscapes that do not consider their nesting preferences.
Looking at the ground layer of plants in woodland gardens, you will see spectacular displays of spring color as many are ephemeral. They gather their solar energy before the trees leaf out. They bloom early and some completely disappear until the following spring. Others offer interesting leaf form, but just shades of green. One way to bring some color to the woodland garden later in the growing season is by adding species that either produce striking fruit (Jack-in-the-pulpit or blue cohosh) or flower in late summer through fall. The best examples of fall blooming shade-tolerant species are Zig Zag goldenrod and big-leaved aster. Both of these species are vigorous spreaders and extremely drought tolerant.
Sedges are another option for ground cover in dark sites with little water (mature trees take up thousands of gallons in a day.) Here in the upper Midwest, we have many species to choose from that yield a lawn-like appearance while requiring little care. You may think of marshes first when you imagine sedges, but there are three that will form solid carpets of low, grass-like foliage. Which species you choose will depend on your site conditions.
Finally, do not feel that you need to convert your entire landscape to native species to be successful. There are many wonderful horticultural varieties that complement the native woodland habitat. You may start adding native diversity with just a few species that are best suited to your situation. As you gain experience with them, you will find you need to spend less time tending them than the introduced plants; therefore, you may find the ecological approach to be a tremendous savings of both your time and money as you create critically important habitat for birds and other creatures.
Shade Landscape in Mid Winter
Shade Landscape in Early Spring
Shade Landscape in Early May
Shade Landscape in Mid May
Shade Landscape in Mid Summer
Please visit these other contributors to this month’s Garden Designer’s Round Table: