AMES, Iowa — If planning for next year’s garden includes finding new plants for shady areas, consider the recommendations of Iowa State University Extension and Outreach horticulturists while paging through and ordering from garden catalogs this winter. The horticulturists also answer questions that come to Hortline, Iowa State’s horticulture hotline. Reach Hortline by calling 515-294-3108 or emailing firstname.lastname@example.org.
Annuals that can be successfully grown in shady areas include wax begonia (Begonia x semperflorens-cultorum), impatiens (Impatiens walleriana), lobelia (Lobelia erinus), coleus (Solenostemon scutellarioides), wishbone flower (Torenia fournieri) and pansy (Viola x wittrockiana).
Perennials that are good choices for partially to heavily shaded locations include black snakeroot (Actaea racemosa), red baneberry (Actaea rubra), lady’s mantle (Alchemilla mollis), astilbe (Astilbe spp.), Japanese painted fern (Athyrium niponicum var. pictum), heartleaf brunnera (Brunnera macrophylla), bleeding heart (Dicentra spp.), Hakone grass (Hakonechloa macra), hosta (Hosta spp.), crested iris (Iris cristata), cinnamon fern (Osmunda cinnamomea), creeping phlox (Phlox stolonifera), Jacob’s ladder (Polemonium caeruleum), lungwort (Pulmonaria spp.), celandine poppy (Stylophorum diphyllum) and toad lily (Tricyrtis spp.).
When selecting plants for the shade garden, one group of plants that is often overlooked are native woodland wildflowers. Since they are native to the state, woodland wildflowers are well adapted to the area. They are easy to grow and perform well when given a favorable environment.
Native woodland wildflowers that make good additions to the home landscape include wild columbine (Aquilegia canadensis), Jack-in-the-pulpit (Arisaema triphyllum), goat’s beard (Aruncus dioicus), Canadian wild ginger (Asarum canadense), Dutchman’s breeches (Dicentra cucullaria), shooting star (Dodecatheon meadia), false Solomon’s seal (Maianthemum racemosum), Virginia bluebells (Mertensia virginica), woodland phlox (Phlox divaricata), May apple (Podophyllum peltatum), Solomon’s seal (Polygonatum biflorum), bloodroot (Sanguinaria canadensis), trillium (Trillium spp.), merrybells (Uvularia grandiflora) and others.
Obtaining plants is easy. Woodland wildflowers are readily available at garden centers and mail-order nurseries. Do not remove plants from natural woodland areas.
Excellent groundcovers for shade include bugleweed (Ajuga spp.), wild ginger (Asarum canadense and A. europaeum), barrenwort (Epimedium spp.), sweet woodruff (Galium odoratum), hosta (Hosta spp.), yellow archangel (Lamium galeobdolon), spotted deadnettle (Lamium maculatum), creeping lily-turf (Liriope spicata), Japanese pachysandra (Pachysandra terminalis), lungwort (Pulmonaria spp.), foam flower (Tiarella cordifolia) and vinca (Vinca minor).
Variegated bishop’s weed (Aegopodium podagraria ‘Variegatum’) and lily-of-the-valley (Convallaria majalis) are two other shade-tolerant groundcovers. Unfortunately, both plants spread rapidly and often become invasive. These aggressive spreaders should not be planted with other perennials as they quickly crowd out neighboring plants. Variegated bishop’s weed and lily-of-the-valley should be planted only in areas where they can be confined (for example, between a building and sidewalk) or allowed to spread freely.