Before choosing plants for a bed in dry shade, I make adjustments to the site to promote healthier, more vigorous growth. If possible, when planting under a tree, I remove some of the lower and mid-level branches to allow more light to the bed. Then, if needed, I add organic matter to the soil to improve moisture retention and fertility. If planting beneath a mature tree, I prefer to use small plugs between tree roots in enriched pockets of soil. After the initial planting, I mulch around each plant to help retain moisture, and for the first year, I water regularly to establish the plants. In subsequent years, I provide supplemental water during periods of drought.
Plants to avoid
If you’re unfamiliar with local invasive plants, check out the Grow Me Instead guide from the Ontario Invasive Plant Council. Many plants gardeners have used traditionally in difficult areas like dry shade should be avoided because of their invasive status. These include Perriwinkle, Goutweed, Lily of the Valley, English Ivy, and Creeping Jenny.
Designing your space
- When choosing plant material, consider multi-layers above and below ground.
- Plant blooms for the entire season, from early spring ephemerals to late season natives.
- Consider as well the functional and ecological value of the plant species you choose. Do they promote biodiversity? Are they important food or medicine crops? Will they help with water management in your rain garden or with erosion on a slope? Will they improve the resilience and sustainability of your planting?
A few ground covers for dry shade
The following plants, once established, will grow well as groundcovers in dry shade in our area.
Sedges create great soft landings beneath heavy shade trees. Below, left, native Oak Sedge (Carex pensylvanica) and right, native Seersucker Sedge (Carex plantaginea). Sedges are important larval hosts for many lepidoptera species, and their seeds are a valuable food source for birds and small mammals. In larger spaces, use a variety of species for added interest.
Goldenrods are keystone plants, providing nourishment for 104 caterpillar species, 42 pollen specialist bee species, and many for many other pollinators. Native Zigzag Goldenrod (Solidago flexicaulis), below left, spreads slowly by rhizomes and seeds to form a wonderful groundcover. It grows up to 90cm tall, and has lovey, fragrant spikes of flowers which are a pollinator magnet in August and September.
Native Wild Ginger (Asarum canadense), above right, has handsome, kidney-shaped leaves, and unusual bell-shaped, purple flowers in May, hidden at the base of the plant beneath the foliage. It makes a lovely, soft textured ground cover 10-30 cm tall. Note: the European species has shiny leaves unlike our native species.
Native Foamflower (Tiarella cordifolia) grows well in dry shade with rich woodland soil. It is a short plant (15-30 cm) with beautiful shoots of long-lasting white flowers loved by pollinators in mid-May.
Our native violets have important relationships with specialist bees, many species of Frittilary butterflies, and other insect species. Below, left to right, Canada Violet (Viola canadensis), Downy Yellow Violet (Viola pubescens), Sweet White Violet (Viola blanda)
Below: native Wild Blue Phlox (Phlox divaricata) This is a lovely groundcover 25-45 cm. tall, blooming in mid-spring with masses of flowers.
Non-native Japanese Forest Grass (Hakonechloa macra):
This is a stunning, cascading grass about 45 cm tall that lights up a dry shady area. Lovely when planted as a river through a larger bed, and in containers.
Below, left, H. macra ‘All Gold’ and right, H. macra ‘Aureola’
Non-native Barrenworts (Epimedium spp.)
Barrenworts are long living groundcovers with spidery spring flowers and beautiful leaves. Cut back last year’s growth in early spring to better see the lovely flower spikes through the new, emerging foliage. They do exceptionally well in dry shade. For more info: Epimedium at the Gardens—Expanding our Plant Collections | Coastal Maine Botanical Gardens
Below, Epimedium rubra, E. lishihchenii
Below, non-native Hellebores (Helleborus spp.) (These can also be used as seasonal scatter plants if not allowed to self-sow.)
Another long-lived plant, Hellebores are the first bloomers in my garden, sometimes through late winter snows. They flower in a wide variety of colours over several months, and are popular with early emerging bees. They self-sow well, but be patient as seedlings take several years to bloom. Carefully cut back damaged foliage from the previous year in early spring. For more info: Hellebore Care 101: How to grow the harbingers of spring
Other available non-native groundcovers to try: Bigroot geranium (Geranium macrorrhizum) , and Siberian Bugloss (Brunnera macrophylla) (avoid varieties that are aggressive self-seeders).
Architectural, structural plants
In larger spaces, shrubs can create a bold, structural layer. For dry shade, try our native Maple-leaved Viburnum (Viburnum acerifolium), Northern Bush Honeysuckle (Diervilla lonicera),New Jersey Tea (Ceanothus americanus)(part shade), or Fly honeysuckle (Lonicera canadensis). Resembling a shrub, the herbaceous Purple-flowering Raspberry (Rubus odoratus) suckers to form a large colony of foliage, flowers and fruit attractive to bees (and the specialist Rose Miner Bee), lepidoptera, and small wildlife. Below, left, Maple-leaved Viburnum’s fall color, and right, Purple-flowering Raspberry.
Three beautiful, native perennials for dry shade that provide structural height to the bed include, below, from left to right, Great Solomon’s Seal (Polygonatum biflorum), Black Snakeroot (Actaea racemosa), and American Spikenard (Aralia racemosa).
An Asian species, Aralia cordata ‘Sun King’ pictured below, has become popular for its golden foliage. It prefers dappled shade.
Seasonal, theme (scatter) plants
Native Blue-stemmed Goldenrod (Solidago caesia) is another keystone plant for dry shade. This striking goldenrod is taller than Zigzag Goldenrod, growing 30-90 cm, and prefers part shade to shade.
Native ferns make excellent ‘scatter ‘plants in a design: below, left to right, Christmas Fern (Polystichum acrostichoides), Lady Fern (Athyrium felix-femina)
Our native Ontario asters are keystone plants, providing nourishment for 100 caterpillar species, 33 pollen specialist bee species, and many other pollinators. Lovely in dry shade are, below, from left to right, White Wood Aster (Eurybia divaricata), Large-leaved Aster (Eurybia macrophylla) and Short’s Aster (Symphyotrichum shortii).
Hairy Sweet Cicely (Osmorhiza longistylis), below, left. Visited by all sorts of pollinators, this anise-flavoured native herb does well in dry shade.
Other dry shade ‘scatter‘ plants in my garden, above center, Paeonia peregrina, and above right, Lungwort (Pulmonaria spp.)
Ephemerals and non-native bulbs
Don’t forget to include early spring ephemerals like Trilliums, Bellworts, Dutchman’s Breeches, and Hepaticas with non-native bulbs when planting beneath trees and shrubs. Small species (botanical) tulips, narcissus, and other bulbs prefer the dryness of summer and fall when they are dormant, and bloom in the early spring sunshine before trees leaf out.
Below, left to right, Dutchman’s Breeches (Dicentra cucullaria) and Sharp-lobed Hepatica (Hepatica acutiloba)
Below, left to right, Leucojum aestivum (Spring Snowflake) with Hellebores and Dicentra, Tulipa sylvestris, Tulipa clusiana
Gardening in dry shade – a few resources
Bringing Native Plant Communities Home – Wild Ones West Cook Chapter https://westcook.wildones.org
April 10: Bringing the Woodland Home with Roy Diblik of Northwind Perennial Farm (click link to view recording)
NativePlantMatch | Plant For Biodiversity
www.plantforbiodiversity.com
Searchable database to find native plants for your yard:
Native Plants for Dry Shade – Monarch Gardens www.monarchgard.com
Ontario Native Groundcovers for Shade • Native Plant Connection
Native Plants for Dry Shade | In Our Nature Native Plant Nursery — In Our Nature