Shade gardens using native plants

They say shade gardens will be the gardens of the future, providing respite from the heat. Why not create a seating area in the shade? Besides being cool and relaxing, the other advantage over sunny locations is that weeds grow more slowly in the shade. Shady areas also make the perfect play spaces for children as they explore the natural world or find cozy nooks to engage in imaginative play.

Traditional shade gardens

Traditional shade gardens are easily created by choosing shade-tolerant plants. Much of what goes into creating a beautiful shade garden is paying attention to foliage shape and texture and arranging the plants to showcase the flowers, many of whose muted colors look best when viewed close up. Planting in masses can be very effective both for foundation plantings and for conventional borders. Lots of design ideas can be found on this page.

Easy shade plants with pretty blooms

Click on the photos to enlarge and see the names.

Plantings under yard trees

Special considerations are posed by thin, compacted soil and competition for moisture from tree roots. If done carefully, adding other native plants can benefit your trees as well as add interest and habitat value to your yard. Lawns are not good for trees, given the compaction, lime and other chemicals that may be applied, and the risk of injury from lawn mowers and string trimmers. Connecting them by islands of naturalized areas where fallen leaves are left in place (and not piled deeper than normal) solves these problems. Weeding requirements are relatively light in the shade compared to in the sun. 

 

Great caution needs to be taken to avoid damaging tree roots, which are quite shallow and extend quite a ways beyond the drip line. A rule of thumb, so to speak, would be not to cut a root that is wider than your thumb. Half of the trees’ roots grow within the top six inches of soil, and most of the rest are within the top two or three feet. Trees with damage to over a quarter of their roots may slowly die; in some cases such as Tulip Poplars, compaction by heavy machinery is enough to threaten them. Many plants can be found for sale as two inch plugs, which are easily installed and are much less expensive. Adding shrubs or other trees is more difficult but can be done if you are careful. The big problem with them is that although some shrubs and trees will survive in shady conditions, only a few will grow, flower or bear fruit, and fewer still can get by in bone dry conditions.

 

You may notice that there are few plants in the woods that grow right up against the trunk of the trees. Trees help each other to grow via underground fungal connections, but they also put out chemicals that inhibit the growth of other plants right next to them, thus reserving the space for their own needs. Different tree species may tolerate different understory plants. This is an area that has not been studied enough to give us clear planting advice, but this spreadsheet lists some anecdotal observations by Virginia gardeners and naturalists of some plants thriving within a yard or so of a tree. You can help us add to this list by emailing your observations to plantnovanatives@gmail.com. 

 

Tempting though it is, do not pile soil on top of tree roots in order to create a garden, as you will be suffocating the tree. You may add a few inches of large wood chips, since water and oxygen can penetrate them. As they break down, the added organic matter may benefit the tree as well as your other plants. Thin layers of shredded mulch are acceptable. In no case should mulch or chips be touching the tree itself.

Woodland paths

Woodlands present the interesting challenge of keeping the plants from blending into the rest of the undergrowth and losing their visual impact. If you want to mimic the effect of a public garden with masses of planted species, and you don’t want to wait for decades to achieve that effect, you will need to plant very densely, because most shade tolerant plants spread quite slowly, if at all, in the woods.

Alternatively, you can use more scattered species as fun “surprises” along the path. To keep it from just looking like an untouched woodland, you can add human touches such as branches to delineate the path, vases to raise up some of the smaller plants to be more easily viewed, or statuary. (Natural woodlands are what are actually needed from a habitat perspective: our attempts at improvement can easily do more harm than good as we disturb the soil and introduce unsuitable plants.  If your goal is to maximize the habitat value of your woods, simply remove invasive introduced plants and provide deer protection. You will be amazed at how many native plants come up from the seed bank once deer pressure is removed.)

 

Is the ground too dry? One way to increase moisture in the woods is to tuck your plant right next to a log.

IMG_9288.JPG

Spring Ephemerals

Shade is exactly where spring ephemerals belong, underneath deciduous trees and shrubs. They delight us as they emerge in early spring, getting their sunlight before the trees leaf out and going dormant once the leaves appear or the soil gets too dry.  See our page on spring ephemerals.

Mertensia virginica Virginia bluebell.jp

Virginia Bluebell (Mertensia virginica)

unnamed.jpg

Groundcovers

 

Most native plant that work well as groundcovers - and there are many - are shade plants. See our page on native groundcovers.

How shady is it?

If you overestimate how much sun an area gets, you may be quite disappointed. Overoptimism on this score may cause you to install a plant that survives but never thrives. Bright shade opens up a lot more possibilities. Just remember, “full sun” does not mean that there are times when the sun hits it directly. It means that the sun hits it directly for at least six hours a day. Part sun/shade means the sun hits it directly from 2 to 6 hours a day. That still leaves plenty of plants that do well with under 2 hours of direct sun per day (full shade), although of course there are limits to how dark it can be. Very few things will grow right under a beech tree, for example, which produces not only dense shade but very dry soil.


It is not easy to find sources that refer to the degree of shade that a plant tolerates. Typically they will just say “Shade.” In some cases, you might find more precise designations within the Shade (less than 2 hours direct sun per day) category:

 

  • Light shade sites receive partially filtered sun, such as that found under open canopied trees, where there is an ever-moving pattern of sun and shade. You may see light shade referred to as dappled shade or intermittent shade.

  • Moderate shade occurs with mostly reflected light, such as at the floor of a hardwood forest.

  • Heavy or dense shade is a site with no direct sunlight, such as at the base of a north-facing wall or below dense evergreen trees.

Trees

Trees make shade, but most of them won’t grow without sun! Unless they happen to be at the edge of the forest, the seedlings pop up on the forest floor and wait until there is a break in the canopy before taking off. Some such as American Holly will grow in full shade, but only really slowly. Within the Full Shade category, trees can be divided the following way.

Heavy shade:

Allegheny Serviceberry (Amelanchier laevis)

Pawpaw (Asimina triloba)

American Hornbeam (Carpinus carolina)

 

Moderate shade:

Red Maple (Acer rubrum)

Downy and Canada Serviceberry (Amelanchier arborea and canadensis)

Hackberry (Celtis occidentalis)

American Beech (Fagus grandifolia)

Sweetbay Magnolia (Magnolia virginiana)

Blackgum (Nyssa sylvatica)

Staghorn Sumac (Rhus typhina)

 

Light shade:

Eastern Redbud (Cercis canadensis)

Fringe Tree (Chionanthus virginicus)

Flowering Dogwood (Cornus florida)

American Holly (Ilex opaca)

Hophornbeam (Ostrya virginiana)

Shrubs

In most cases, you will see much better blooming and faster growth in Part Sun than in Full Shade. Within the Full Shade category, shrubs can be divided the following way.

Heavy shade:

Gray dogwood (Cornus racemosa)

Mountain Laurel (Kalmia latifolia)

Mapleleaf Viburnum (Viburnum acerifolium)

 

Moderate shade:

Red Chokeberry (Aronia arbutifolia)

Swamp Doghobble (Eubotrys racemosa)

Wintergreen (Gaultheria procumbens)

Witchhazel (Hamamelis virginiana)

Smooth Hydrangea (Hydrangea arborescens)

Winterberry Holly (Ilex verticillata)

Virginia Sweetspire (Itea virginica)

Northern Bayberry (Myrica pensylvanica)

Great Rhododendron (Rhododendron maximus)

Fragrant Sumac (Rhus aromatica)

Arrowwood Viburnum (Viburnum dentatum)

Possumhaw Viburnum (Viburnum nudum)

Blackhaw Viburnum (Viburnum prunifolium)

 

Light shade:

Hazelnut (Corylus americana)

Black Huckleberry (Gaylussacia baccata)

Spicebush (Lindera benzoin)

Swamp Rose (Rosa palustris)

Bladdernut (Staphylea trifolia)

Low growing plants for heavy shade

 

Many native plants are shade tolerant, meaning they can get by or even prefer fewer than two hours sun per day. There is no need to list all the native perennials, ferns, sedges and vines that do well in light or moderate shade, because they are so many, and you can find them in the Native Plants for Northern Virginia guide and app. Only a subset of those plants, though, can tolerate truly deep shade, such as under an overhanging, north-facing deck. Dense, dry shade with competing tree roots is a particular challenge.

 

The lists below were gathered from a variety of online sources and word of mouth. Of course, by “very dense,” we do not mean “black,” and by “very dry,” we don’t mean “never gets rain!”

 

Very dense and very dry shade

White Wood Aster (Eurybia divaricata)

Partridge Berry (Mitchella repens) - In the woods, this plant is often found right at the base of trees. Keep leaves off it.

Virginia Creeper (Parthenocissus quinquefolia) - this is an aggressive plant.

Christmas Fern (Polystichum acrostichoides)

Blue-Stemmed Goldenrod (Solidago caesia)

Zigzag Goldenrod (Solidago flexicaulis)


 

Sedges:

Appalachian Sedge (Carex appalachia)

Blue Sedge (Carex flaccosperma var. glaucodea)

Pennsylvania Sedge (Carex pensylvanica)

Eastern Star Sedge (Carex radiata)

Rosy Sedge (Carex rosea)


 

Dense shade but not totally dry

 

Perennials

Black cohosh (Actaea racemosa)

Jack-In-The-Pulpit (Arisaema triphyllum)

Wild Ginger (Asarum canadense)

Crested Iris (Iris cristata)

Golden Ragwort (Packera aurea)

Mayapple (Podophyllum peltatum)

Woodland Phlox (Phlox divaricata)

Solomon’s Seal (Polygonatum biflorum)

Bluestem Goldenrod (Solidago caesia)

Zigzag Goldenrod (Solidago flexicaulis)

Foamflower (Tiarella cordifolia)

Golden Alexandra (Zizia aurea)

 

Shrubs and trees

American Holly (Ilex opaca)

Black huckleberry (Gaylussacia baccata)

Lowbush blueberry (Vaccinium pallidum)

Maple-leaved Viburnum (Viburnum acerifolium)

Pawpaw (Asimina triloba)

Spicebush (Lindera benzoin)

Virginia Sweetspire (Itea virginica)

unnamed (1).jpg

Mayapple (Podophyllum peltatum)

Viburnum acerifolium.jpg

Maple-leaf Viburnum (Viburnum acerifolium

carpinus_caroliniana.jpg

American Hornbeam (Carpinus carolina)

Ferns and Sedges

 

See our pages on native ferns and native grasses.

Carex plantaginea Plantain-leaved Sedge.

Seersucker Sedge (Carex plantaginea)

Deer

 

Many of our woods have been denuded of the ground layer by the deer. Even the tree seedlings have disappeared, which is problematic when you think of the future of the forest. Two categories of plants that you will see growing well despite deer are ferns and sedges. Big drifts of ferns are a very lovely sight - if you like a simple plan with big visual impact, you could compose a garden using just ferns with patches of Virginia Bluebells, as they also are undesirable to deer. Spicebush and PawPaw are likely to do well, as would a number of perennials which you can find using the search function on the Plant NOVA Natives plant app. On the other hand, if you are in a position to provide protection from deer, you will be doing the ecosystem a big favor as you incorporate plants that are threatened elsewhere.