Perennials for Shade and Part Shade: A Toronto Master Gardeners Guide

Perennial ferns, pink Astilbe and Hostas, in one of their many foliage variations, combine beautifully in this shade garden. Photo: Helen Battersby

In the gardening world, the term perennial usually refers to an herbaceous perennial, i.e., a plant without woody tissue, that dies back to the ground at the end of the growing season and grows again from its rootstock in spring.

Many gardeners regard shade as a challenging environment for growing plants and miss the bright flowers of the sunny summer border. However, the inviting green foliage of the shade garden can be a cool and restful contrast, out of the glare of the hot summer sun. Shade garden plants may have quieter charms but come with an impressive variety of leaf texture, foliage colour, shape and form.

Characteristics of shade perennials

Many perennials that thrive in shade have developed differing survival strategies. Some plants, such as hostas and ligularias, have large leaves to capture as much sunlight as possible. Other plants, such as hellebores, bergenias and the Christmas fern, have evergreen leaves, another adaptive strategy for low light.

Another survival tactic of shade perennials is to flower early in the year, before the trees come into leaf.  Our beautiful native spring ephemerals have adapted this strategy, bursting into bloom beneath the still-bare canopy of deciduous trees before dying back in the denser shade of summer.

Shade perennials are slower growing than their sun-loving neighbours and long lived. Choosing larger specimens can help fill the garden in its early years.

In the summer shade garden, the foliage of shade perennials often becomes the focal point. Plants with silvery leaves, such as the spotted lungworts or painted ferns stand out in contrast to their darker, round-leaved neighbours and the lemon-green fronds of Japanese forest grass provide accents like a burst of sunshine.  Using a mixture of shade plants with a variety of leaf colours, shapes, textures and bloom time will create visual and seasonal interest.

Considerations when choosing perennials for shade

Choose plants suited to the growing conditions of your site. This is always preferable and more successful than attempting to change the site to suit the plant. Plants growing in their preferred locations are much more likely to be healthy than plants growing in less-than-optimal conditions. A healthy plant is far more likely to be able to withstand disease and pest problems than a plant that is under stress. Make sure your plants are at least hardy for your gardening zone.

One of the most important factors in choosing shade plants will be determining the amount of available sun/shade. Even within a shady garden, there may be varying levels of shade, ranging from the dappled shade of a lacy tree canopy to the deep shade found beneath evergreens or maples or beside an overshadowing building or wall.

  • Partial shade – plants receive 4 to 6 hours of morning or afternoon sun, but should be shaded from the hot, midday sun.
  • Full Shade – plants can tolerate less than 4 hours of sun, preferably in the morning. A bright location that receives no direct sun would be classified as full shade.

Exposure to wind is also an important consideration for shade plants: they appreciate a cool environment with higher humidity and may need protection from drying winds.

Some shade plants, such as lobelias and ligularias, will need consistent moisture in the soil to thrive while others will adapt to drier garden conditions. Water during dry spells, preferably early in the morning. Even plants tolerant of drier soil will require extra water during the first growing season or until they are established. This is even more important when trying to establish perennials in areas where tree roots are in competition.

Checking the mature height and spread of your plant will tell you the amount of space it will require in your garden for optimum growth. Overcrowded plants become stressed when competing with neighbouring plants for light, nutrients and moisture. As a result, they are more susceptible to diseases, especially those that are encouraged by poor air circulation.

Native plants are always a good choice when planted in the right soil with appropriate light and moisture. Native plants are already acclimated to our soils and climate, have evolved with the birds and pollinators who use them for shelter and food, and help to increase the local biodiversity.

General care and maintenance

Proper soil maintenance is important for perennials since they typically stay in the same location for many years. For shade perennials, fertile soil with adequate moisture content is even more important to help counteract the disadvantage of low light conditions.  Adding organic matter, such as compost or composted manure, as a topdressing around your perennials improves moisture retention in the soil and provides nutrients without disturbing the soil structure.

Lay down a mulch in the form of leaf litter and/or wood chips on the soil’s surface. Mulch forms a barrier which reduces evaporation and traps water, allowing the moisture to drain slowly down into the soil. A layer of mulch will also help suppress weeds and make weed removal easier. Mulch, in the form of leaf litter or wood chips, is home to countless beneficial organisms and contributes valuable nutrients back to the soil as it decomposes.

Perennials should be dead-headed regularly to keep their appearance tidy and to encourage plants to put their energy into flower production, rather than seeds. Good sanitation practices are also important. Remove any diseased or decaying plant material and dispose of it off-site. Ensuring good air circulation around your plants is also very helpful for avoiding or minimizing most fungal diseases

When combating an insect problem, always choose the least aggressive approach and only as a last resort. Remember that there may already be beneficial predatory insects, such as parasitic wasps, sawflies, beetles and spiders in your garden looking for a handy meal. Spraying water from a hose can knock off most aphids and spider mites. Hand picking for larger insects is also an option. Approved insecticidal soaps may be used for control measures. Insect traps and organic dust barriers can be effective for crawling insects. Natural insect controls include lady bugs and nematodes.

The following is a list of recommended shade plants hardy in Toronto.  Native plants are marked with the letter N.

Recommended species/varieties/cultivars:

Perennials for part shade in moist soil

Groundcovers and low growing perennials:

  • Lady’s mantle (Alchemilla mollis)
  • Canada anemone (Anemone canadensis) – N Spreads readily
  • Dwarf goat’s beard (Aruncus aethusifolius)
  • Wild ginger (Asarum canadense) – N
  • Chinese astilbe (Astilbe chinensis pumila)
  • Astilbe (Astilbe simplicifolia hybrids)
  • Bergenia (Bergenia cordifolia)
  • Siberian bugloss (Brunnera macrophylla)
  • Carpathian bellflower (Campanula carpatica)
  • Yellow corydalis (Corydalis lutea) may self-seed
  • Wild bleeding heart (Dicentra cucullaria) ( canadensis) – N
  • Bleeding heart (Dicentra eximia) ( formosa hybrids)
  • Barrenwort (Epimedium hybrids)
  • Sweet woodruff (Galium odoratum)
  • Cranesbill (Geranium maculatum) – N
  • Bloody cranesbill (Geranium sanguineum)
  • Coral bells (Heuchera sanguinea) (H. micrantha) and hybrids
  • Foamy bells (x Heucherella) hybrids of Heuchera and Tiarella
  • Virginia waterleaf (Hydrophyllum virginianum) – N
  • Lamium, dead nettle (Lamium maculatum) * choose cultivars rather than the species which could become invasive in natural areas
  • Variegated lily turf (Liriope muscari ‘Variegata’)
  • Drumstick primula (Primula denticulata) plus other species
  • Lungwort (Pulmonaria saccharata) plus other species and hybrids
  • Foamflower (Tiarella cordifolia) – N plus hybrids
  • Large-flowered bellwort (Uvularia grandiflora)
  • Barren strawberry (Waldsteinia fragarioides) – N

Medium to tall border perennials:

  • Monkshood (Aconitum carmichaelii ‘Arendsii’) * Warning – all monkshoods are poisonous
  • Black cohosh (Actaea racemosa)
  • Bugbane (Actaea simplex (Atropurpurea Group))
  • White snakeroot (Ageratina altissima ‘Chocolate’)
  • Japanese anemone (Anemone hybrids)
  • Japanese spikenard (Aralia cordata ‘Sun King’)
  • Goat’s beard (Aruncus dioicus)
  • Astilbe (Astilbe x arendsii hybrids)
  • Astilboides (Astilboides tabularis)
  • Columbine (Aquilegia canadensis) – N  plus other non-native species and hybrids
  • White turtlehead (Chelone glabra) – N
  • Umbrella plant (Darmera peltata)
  • Yellow foxglove (Digitalis grandiflora)
  • Joe Pye weed (Eutrochium purpureum) ( maculatum) – N
  • Rozanne geranium (Geranium ‘Gerwat’) plus other border varieties
  • Mourning widow geranium (G. phaeum)
  • Bowman’s root (Gillenia trifoliata)
  • Hellebore, Lenten rose (Helleborus orientalis) plus hybrids
  • Coral bells (Heuchera sanguinea) plus hybrids
  • Hosta, plantain lily (Hosta cultivars) look for the slug resistant varieties
  • Yellow wax bells (Kirengeshoma palmata)
  • Bleeding heart (Lamprocapnos spectabilis)
  • Ligularia (Ligularia dentata) (Ligularia ‘The Rocket’)
  • Cardinal flower (Lobelia cardinalis) – N
  • Great blue lobelia (Lobelia siphilitica) – N
  • False Solomon’s seal (Maianthemum racemosum) – N
  • Solomon’s seal (Polygonatum biflorum commutatum) – N plus other species
  • Primrose (Primula japonica) plus other species and hybrids
  • Rodgersia (Rodgersia podophylla) plus other species
  • Meadow rue (Thalictrum aquilegiifolium)
  • Spiderwort (Tradescantia virginiana) ( (Andersoniana Group) ‘Sweet Kate’)
  • Globeflower (Trollius x cultorum)

Perennials for shade in moist soil

Groundcovers and low growing perennials:

  • Canada anemone (Anemone canadensis) – N
  • Wild ginger (Asarum canadense) – N
  • Chinese astilbe (Astilbe chinensis pumila)
  • Siberian bugloss (Brunnera macrophylla)
  • Wild bleeding heart (Dicentra cucullaria) ( canadensis) – N
  • Bleeding heart (Dicentra eximia) ( formosa hybrids)
  • Barrenwort (Epimedium hybrids)
  • Sweet woodruff (Galium odoratum)
  • Bigroot geranium (Geranium macrorrhizum)
  • Lamium, spotted dead nettle (Lamium maculatum) * choose cultivars rather than the species which could become invasive in natural areas
  • Variegated lily turf (Liriope muscari ‘Variegata’)
  • Creeping phlox (Phlox stolonifera)
  • Woodland phlox (Phlox divaricata) – N
  • Lungwort (Pulmonaria saccharata) plus other species and hybrids
  • Foamflower (Tiarella cordifolia) – N plus hybrids

Medium to tall border perennials:

  • Astilbe (Astilbe x arendsii hybrids)
  • Large-leaved aster (Eurybia macrophylla) – N
  • Hosta, plantain lily (Hosta cultivars) look for slug-resistant varieties
  • Zigzag goldenrod (Solidago flexicaulis) – N
  • False Solomon’s seal (Maianthemum racemosum) – N
  • Solomon’s seal (Polygonatum biflorum commutatum) – N plus other species

Grasses for shade

  • Bulbous oat grass (Arrhenatherum elatius bulbosum ‘Variegatum’)
  • Bowles’ golden sedge (Carex elata ‘Aurea’)
  • Japanese sedge (Carex morrowii ‘Variegata’) plus other species
  • Northern sea oats (Chasmanthium latifolium) – self-seeds
  • Tufted hair grass (Deschampsia cespitosa)
  • Variegated Japanese forest grass (Hakonechloa macra ‘Aureola’) plus other cultivars
  • Moor grass (Sesleria autumnalis)

For more perennials for dry shade/part shade, including more native plants, see Drought Tolerant Perennials: A Toronto Master Gardeners Guide.

 For shade tolerant ferns, see Hardy Garden Ferns: A Toronto Master Gardeners Guide

References

Grow Me Instead: beautiful non-invasive plants for your garden. Ontario Invasive Plants Council, 2020.  https://www.ontarioinvasiveplants.ca/wp-content/uploads/2020/04/Southern-Grow-Me-Instead-1.pdf

Harris, Marjorie. Favorite shade plants. Harper Collins, Toronto, 1994.

Hodgson, Larry. Making the most of shade: how to plan, plant and grow a fabulous garden that lightens up the shadows. Rodale Books, 2005.

Tenenbaum, Frances, ed. Taylor’s 50 best Perennials for Shade. New York: Houghton Mifflin Company,1999

Date revised: February 2022

Prepared by the Toronto Master Gardeners, these Gardening Guides provide introductory information on a variety of gardening topics.  Toronto Master Gardeners are part of a large, international volunteer community committed to providing the public with horticultural information, education and inspiration.  Our goal is to help Toronto residents use safe, effective, proven and sustainable horticultural practices to create gardens, landscapes and communities that are both vibrant and healthy.

Statement on Invasive Plants: When choosing plants, avoid invasive plants, which can spread quickly and dominate gardens.  Invasive plants are sold by nurseries, big box stores or even at community plant sales.  Invasives may already be present in your garden.  They can invade gardens by spreading from under a neighbour’s fence or may be transported by wildlife.  For beautiful, sustainable options to invasive plants, see the Ontario Invasive Plant Council’s “Grow Me Instead – Beautiful Non-Invasive Plants for your Garden” at https://www.ontarioinvasiveplants.ca/resources/grow-me-instead/before purchasing or accepting “gifts” of plants.

Statement on Home Remedies: The Toronto Master Gardeners do not recommend home remedies, as these have not been proven effective through scientific investigation, and may even damage other living organisms in the soil or plants in your garden.  There are other garden friendly options you can use.

If you have further gardening questions, reach us at our gardening advice line 416 397 1345 or by posting your question here in the Ask a Master Gardener section.  To book Toronto Master Gardener volunteers for talks, demonstrations, advice clinics, or other services, please contact us at 416 397 1345  or bookamg@torontomastergardeners.ca