16 June 2010

Planting for Shade

The crazy rush in the greenhouse has come and gone with the May long weekend.  Now is a good time to check out the variety of plants available.  Shady areas sometimes are daunting to gardeners.  Sure we know what to plant in sun but what about the shade?  Dry shade, moist shade?  Dappled shade, dense shade. What grows where?  Below is a short but not exclusive list of suggested plants.

Evergreens (trees/shrubs):

 Alberta Spruce (picea glauca) seems to do extremely well in shade, particularly if the prescribed area is shady January through April.  This dwarf evergreen tends to burn (browning of foliage) if planted in an exposed area.  Somewhat moist soil, but not wet.  Well-drained.

Another you might consider is cedar (thuja occidentalis), both upright and global.  Somewhat moist soil but not wet.  Over the years, the foliage of the cedar may tend to become sparse when planted in shade.  Cedars tend to suffer from winter burn/sunscald like the Alberta Spruce.

Boxwood also grows well in shade. An evergreen, it should be planted in a sheltered location out of scorching sun and wind. An anti-desiccant spray is recommended. If you can find the Calgary boxwood, I highly recommend this variety to many others on the market.

Deciduous Shrubs:

 Dwarf European Cranberry (viburnum opulus), a small rounded deciduous bush with excellent fall colour. Grows about 2-3 feet high and wide.  Rarely flowers or fruits. 

Hydrangea - partial sun - full sun.  There are many varieties of hydrangea with varying size, shape and colour of blossom.  Hydrangeas like moisture and if planted in full sun, may wilt during hot spells.  Quite often, it is recommended to plant in a partial shade location, especially shady during the heat of the day.

Rhododendron and Azalea - both prefer partial shade to full sun.  They are shallow rooted, so be careful they don't sit in wet soil.  An anti-desiccant spray may be necessary in the fall for the rhododendron if it is in a particularly windy site.  See previous article about rhododendrons on this blog. 

Rhododendrons are evergreen meaning their leaves remain on the shrub.  They flower early spring (May).  During cold weather you will notice the leaves of the rhodendron tightly curl.  Not to worry, they unfurl as soon as temperatures are in the high single digits.  All parts of the rhododendron and azalea are poisonous.

Azaleas bloom early spring before they are fully leafed out.  Leaf shape is similar (as are growing needs) to rhododendron.  Incidentally both bear the Latin name rhododendron.


Hostas:  Blue Halcyon, Big Daddy, Sum and Substance are just a few varieties available.  There is a wide selection available from miniatures to large varieties with leaves as large as a child's head!  Blue varieties prefer full shade as they scorch easily.  Variegated varieties can withstand some sun if they get afternoon shade.  Varieties with thick leaves are more slug resistant.  Hostas prefer a dry shade.

AstilbeAstilbes grow best in a shady location.  Be careful the soil does not dry out between watering.  They prefer a woodland type setting, meaning a humus soil.  I mulch with wood shavings.  Astilbe are available in a range of colours including pink, red, white, and lavender.

Ferns:  There are many varieties of fern and all prefer a moist soil.  Try Ostrich Fern for height at the back of a shady bed.  Incidentally, the fiddlehead fern and ostrich fern are the same plant.  The fiddleheads (small, young curled frond - new growth before it opens up and grows) can be cooked and eaten.  Seek instructions on doing so before taking it on.  Another pretty one is the Japanese Painted Fern with silvery and burgundy foliage.  Lady Fern and Royal Fern are both hardy in zone 3.

Shooting Star.  A pretty plant with lavender or bright pink blossoms, it grows naturally in the wild.  Please do not cultivate from its natural habitat.  Purchase from a reputable nursery.  This perennial will "disappear" over the hot summer only to reappear next spring. Does not like to dry out.

Ligularia:  Often with large showy leaves ligularia is a nice show piece.  The flower shape depends on the variety, either elongated as in "The Rocket" or daisy shaped "Britt Marie".  Both like a moist soil and shade from the hot afternoon sun.  They can wilt easily.  I find the shadier, the better unless it is planted in a "wet" site.

Bleeding Heart:  Can and usually does die back through the heat of summer and reappears again the following spring.  This plant is poisonous to pets and children.  Can withstand some sun, preferably not hot afternoon sun, but grows equally well in shade.

Coral Bells (Heuchera):  Available with different leaf colour including green, purple, and marmalade (that is its name).  Grows best in shade.  Palace Purple will brown out in the sun, looking crispy.  Red flowers or pale pink, depending on the variety, grow at the ends of long spikes in summer.  Green-leaved varieties tend to be more hardy.

Primrose (Primula):  Grow well in partial shade or dappled shade.  May wilt in direct hot afternoon sun.  A low-growing plant, it is available in a large variety of colours: purple, orange, pink, yellow, white, red.  Very pretty at the front of a shady border.

Creeping Jenny - a low-growing creeping ground cover for sun or shade.  Often grown near ponds for a natural effect.  Creeping jenny is available with a yellow leaf or green.  Both have the same growth habit and are sometimes grown in containers as trailers.  (though they will not overwinter in a container).  Yellow flowers.


Impatiens:  available in many colours including pink, white, red.  Prefers shade. Cannot withstand frost.  A low-growing annual favored by many for its ability to create masses of colour when densely planted.

Begonias:  Either tuberous (you lift the tuber in the fall and store indoors over winter) or fibrous (annual - dies after frost).  Many colours available including yellow, orange, pink, white.  Trailing begonias are also available and look great in a planter or hanging pot in the shade garden.

Coleus:  The leafy coleus is grown for its foliage which varies with variety.  There are some stunning cultivars now from pink with green, burgundy and green, and more. Coleus will bloom but they maintain their shape better if you pinch out the less-attractive flowers as they appear.

Lobelia:  Often grown in planters, lobelia is either upright or trailing.  I love the trailing lobelia combined with red flowers whether they be begonias or geraniums or whatever.  They will grow best in shade.  There is also a perennial variety called Lobelia Cardinalis which is an upright variety with red blooms.  Prefers a shady site.  A stunning site is a shade bed planted with red begonias or impatiens and fronted with trailing lobelia.  The juxtaposition of colour is very dramatic.

Caladium:  With colourful foliage, the caladium is another possibility for the shade garden.  It is grown for its foliage and looks nice in a planter or directly planted in the ground.  Wonderful colour!


Some vines do well in shade but there aren't many.  Try the Henrii Clematis.  It has large white flowers and is stunning in the evening garden.  Or Nelly Moser Clematis with large pink flowers.  Its colour is best if protected from the afternoon sun.  Clematis must have a trellis or other object to climb.  Be sure to plant deep, an extra 6 inches to a foot deeper than what they were planted in the pot.  This helps prevent Clematis wilt, an unsightly disease which is evident with blackening foliage and stems and general lack of vigour.  Check with your local garden center for treatment if you suspect this disease exists.  Clematis come back year after year.

Morning Glory Vine (annual): Grow the annual Morning Glory Vine where it receives morning sun and afternoon shade.  Flowers open in the morning and close at night.  Stay away from the perennial morning glory vine.  It is highly invasive and almost impossible to be rid of.  In BC, particularly on the coast, the vine has been known to grow into the soffits of homes it is planted next to and cause damage.  Even here in Edmonton, I know a gardener who constantly battles to remove this "weed" from her property.

*This list does not contain all possibilities but rather is intended to give you a head start on ideas when you head to the nursery.  All listed are hardy to zone 3 with the exception of the annuals, of course, which can be grown seasonally in most zones.  Good shopping.


Shirley said...

Most varieties of Heuchera are listed as hardy to zone 4 but I have grown two varieties for several years. I have lost a couple this past winter but luckily they will self sow!

Jane said...

These are beautiful photos of your flowers and I like reading your descriptions too!

Shirley said...

Thank you for visiting Jane!

Keith said...

Might I add Tricrtis too as shade loving perennials (here in the UK at least). Will positively thrive as long as there's a reasonable amount of moisture, with the added bonus of being late flowering too.


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