Reliable, must-have perennial plants every gardener should try

Hydrangea.

Peony.

By Dorothy Dobbie

It is a challenge to choose plants for a new garden. They are all so enticing, and each of us has our own vision of beauty and wonder. But some plants are more reliable than others are and really do a solid, dependable job in any garden.

While new gardeners are often thrilled by the big, blowsy blossoms of more tender plants, the long-time gardener will appreciate these but understand that they are often ephemeral, need fussing and many are fair weather friends. Literally. Instead, experienced gardeners choose the hardy imports and native plants as the real workhorses of a perennial garden. Many of the natives are very showy. Then there are the exotics, those plants that have adapted well to our climate including shrubby plants such as hydrangeas, peonies and roses, and true herbaceous flowers including delphiniums and phlox. All these plants have been bred to be extremely hardy in Canada.

The hardy imports

Hydrangeas. Hydrangeas will take partial shade, getting by, if planted with a southern exposure, on as little as three hours of sun a day. The heritage varieties, Hydrangea arborescens and H. paniculata, both bigleafed hydrangeas that need medium to moist soil, are hardy to Zone 3. They are tremendous performers in the right spot. Especially lovely is H. arborescens ‘Annabelle’, a plant that has been gracing Canadian gardens for decades. She produces big white puffballs from June or July to August and up to early September depending on where you live. The flowers are beautiful cut for a bowl or dried for winter enjoyment.

Today, there are cultivars that cover the rainbow of colours in the whites, pinks and even and blue, but these are fussier and may pose a challenge for a new gardener.

Single peonies.

'Never Alone' rose.

Blue delphinium.

'Morden Sunrise' rose.

Peonies (Paeonia). Think of the beautiful peony; surely few things more lovely exist. The cultivars from Japan, the Itoh peonies, which are a cross breed between traditional herbaceous peonies and tree peonies, come in stunning, almost fluorescent, colours. No spring garden should be without peonies which also provide nice shrubby backdrops post bloom and that add substance to the garden. If you hate the petal drop after a heavy rain, try some of the exquisite single-bloom varieties. Peonies can live up to 80 years and even beyond if their roots are divided every so often.

Roses (Rosa). Many of the first Europeans to inhabit Canada were the British and the French, who both love roses and have spent a couple of hundred years figuring out what works in our climate. Some of the very best roses come from two of the country’s harshest climates: Manitoba and Ottawa. Using root stock from the wild

Blue delphinium. rose that grows naturally on this continent has made all sorts of cultivars possible.

From a heritage and hardiness perspective, rely on the three series of bush roses bred in Canada. The Parkland series was bred in Morden, Manitoba, and the Explorers series and the Artists series come from Ottawa and the Agricultural Canada people. Take a look at the small patio rose, ‘Never Alone’. It is a single-petalled pink, merging to white in the centre. It never stops blooming, nor does the pink multi-petalled Explorer ‘Lambert Closse’. It blooms from spring through to October.

Wonderful varieties are emerging all the time and, while they aren’t the tea roses of England, they range from lovely singles to multi-petalled floribundas that would satisfy any yen for big blooms.

These roses are easy-care plants that don’t require complicated pruning or special protection, but they do like plenty of air. Every garden should have some. They come in all sort of heights and spreads, from creeping carpet roses to bush roses that can vary from three to six feet, to climbers. Many will re-bloom in fall. They need full sun to partial shade, requiring four to six hours of sun a day.

Delphiniums. Tall and statuesque, delphiniums cause a stir wherever they bloom. They steal the show in any garden. The Pacific Giants are particularly magnificent and can reach six feet or more in brilliant colour ranging from white to shades of blue and purple to mauve. They might require staking.

They have a small little annual cousin, the larkspur, which is a delightful companion and very easy to grow from a few seeds.

Delphs are rather short-lived perennials but they generously self-sow and will appear to stay around for a long time as they regenerate from seed. They don’t add bone to the garden as do peonies and rose, but they may rebloom in fall if you cut them back early. Full sun, although they will do well in part afternoon shade. Rich, moist soil.

Larkspur.

Phlox.

Phlox 'David'.

Rudbeckia.

Filipendula.

Phlox. Nothing is more rewarding than phlox in a Canadian garden because they come into their own just when it seems that the garden is done for the summer. The early varieties start putting on a show in late July and one or another of them keeps on blooming right through to September and beyond.

This is a very reliable perennial, easy to grow and needing little care. ‘David’ is one of the very best. It is pure white and is just three feet in height and spread. It keeps its place with dignity and does not sprawl although clumps will get incrementally larger. There are also pinks, purples, red and bi-colour varieties.

Daylilies (Hemerocallis). Now that the red lily leaf beetle has all but spoiled the joy of growing lilies in many Canadian gardens, daylilies have become more important as the go-to flower in the midsummer garden. Their strappy leaves provide some eye relief all year round and when they send up their showy scapes of dazzling blooms, the world stops to have a second look. There are even rebloomers, not just in yellow as in the tried and true ‘Stella d’Oro’, but now in purples and pinks.

These lovely flowers can do well in both sun and part shade and also provide the garden with bones, their leaves almost as attractive as the flowers, adding texture to the border in the non-blooming stages.

The natives

The truly healthy Canadian garden will have a substantial number of native flowers, both for beauty and to satisfy the local pollinators. There are so many wonderful choices, but we will start with a group of must-haves for new gardeners to build on.

Daylily 'Blue Eyes'.

Bee balm.

Veronica spicata.

Veronica teucrium 'Royal Blue'.

Culver's root (Veronicastrum virginicum).

Bee balm or bergamot (Monarda). The lovely native bee balm is an irresistible pollinator and bird attractor. It smells wonderful. It usually can escape its tidy clumps as it has a rhizomatous root system. It blooms in pink, red or purple. Anywhere from 24 to 36 inches tall (sometimes a little taller if really happy), it blooms in mid summer.

Yellow coneflower or brown-eyed Susan (Rudbeckia). No fall garden is complete without the yellow-ray blooms of this cheery prairie plant. A short-lived perennial, there are also biennial and annual varieties that will self-sow quite willingly. That is one of the charming things about the natives; they like to plant themselves in the fall to spring back to life the coming year. Rudbeckia hirta ‘Moreno’ has wide swathes of red blending to yellow surrounding dark brown centres. Some have green centres as in R. ‘Lorraine Sunshine’ and ‘Irish Eyes`. There are also double varieties. Clumps are generally 18 inches to 2 feet wide.

Meadowsweet (Filipendula). Filipendula rubra, also known as queen of the prairie, is a very rewarding native variety. Very tall, sometime reaching seven to eight feet in midsummer, queen of the prairie sends up glorious plumes of pink resembling candyfloss. It likes rich humus soil and will grow in part shade and sun. It spreads graciously over many years. Put this plant at the back of the garden to provide a stunning backdrop for big-leafed hostas.

Speedwell (Veronicastrum and Veronica). There are many veronicas, but a nice planting companion for the giant filipendula is Veronicastrum virginicum, commonly called Culver’s root. ‘Diane’ is a statuesque white variety that bees and butterflies cannot resist.

If you like blue, then you will love Veronica teucrium ‘Royal Blue’. A low-growing plant at perhaps 20 inches, it blooms for many weeks, leaving a nice well-behaved clump behind when the blooms are spent.

Finally, best known perhaps is Veronica spicata, also called spike veronica, with its spikes of blue of purple. This is another long lasting staple in the garden.

Joe Pye weed.

Echinacea 'Green Envy'.

‘Karl Foerster’ sets the stage.

Viburnum.

Joe Pye weed (Eupatorium). A hero in any garden but much taken for granted in Canada is Joe Pye weed. I have seen Joe Pye taking pride of place in a many an English garden. There are now many cultivars, and they are all wonderful. This is another butterfly and bee magnet. Joe Pye blooms in late summer and likes a dampish location. The flowers are umbels of pink, red or white.

Purple coneflower (Echinacea). Coneflower has been bred in so many permutations now that it is hard to remember the original stately flower with its purplish rays surrounding a mounded centre. Now the hybrids come in every colour of the rainbow from white to orange to red and yellow and with many different-shaped blooms. But the simple old wildflower graces the garden with dignity and a long-lasting display in late summer.

Blanketflower (Gaillardia). Gaillardia is another of our natives that has been twisted into many shapes and sizes, but the original is quite stunning with its red and yellow petals surrounding a nectar-rich centre. It is easy to grow from seed and will bloom for long weeks throughout summer. It is perfect for that hot dry place in the garden. It grows as both an annual and as a perennial.

‘Karl Foerster’ grasses (Calmagrostis x acutiflora). If there is a stalwart in the garden, ‘Karl Foerster’ is it. A North American native, this upright plant is statuesque and beautiful in all seasons, bright green in summer, developing its feather reed tops as the season progresses and fading to a creamy gold in fall. It stays aloft all winter. ‘Karl Foerster’ is a clumping grass, staying staunchly in its structured space. It is ideal for a dry, sunny yard, perhaps planted among river stone in disciplined rows. It grows three to four feet tall and the clumps have a spread of 18 to 24 inches.

Echinacea purpurea.

Echinacea simulata.

Gaillardia cultivar.

Lilac.

The Woody Bones

Recommending shrubs across the country can be tricky as southern Ontario and the Coastal regions support far more variety than the Zone 3 regions that span most of Canada, but the tried and true shrubs that can form the bones of a new garden even in the higher-Zone regions.

Viburnum. This group of shrubs will grow anywhere from Zone 2 and up and its variations are stunning. It can be a small compact dwarf shrub at 1 to 2 feet tall and wide to a 20-foot tree. It often, but not always, features maple-leaf shaped, corrugated leaves. It is very hardy and reliable, happy to grow in sun or part shade, depending on the variety. Some feature lovely leaves, some brilliant berries as in ‘Blueberry Muffin’ and others, such as the snowball viburnum, have big hydrangea-type blossoms. Nannyberry is a viburnum as is the highbush cranberry.

Lilac (Syringa). We all think we know lilacs, that familiar bringer of spring joy, but much has happened over the past number of years. There are many varieties of this beautiful shrub, some of them re-blooming, some with picotee flowers that have a white rim around the edges of each tiny blossom and others that will stay small and compact.

They range in colour from pink to purple to white, with many shades in between. Some are more fragrant and some have tubular-shaped blossoms instead of the tight flowers of the traditional lilac. It pays to check your preferences carefully and know what to ask for when purchasing. Check also for scent.

Heritage types can live for 200 years. They can grow pretty much anywhere in the more populated areas of Canada.

Lilac hedge.

Barberry Sunjoy 'Mini Maroon'.

Pulmonaria.

Berberis, barberry. Barberry once had a bad name as a spreader of rust disease that affected wheat crops. It re-emerged a few years ago with that negative characteristic bred out and it has proven to be a real winner for its plethora of sizes, shapes and amazing leaf colour. Barberry also has sharp thorns. Some bear red berries, although they do not have showy flowers. It is available in sizes from very small dwarf, to medium mounded to large spreading varieties. Colours range from glowing lime green to reds to burgundies and even orange. Some leaf colour changes with moving light. This is an excellent choice to add texture and all season colour to the perennials bed.

Spirea. Hardy and healthy, spirea puts on a show in springtime, producing umbels of pink or sprays of white, depending on the variety. Goldflame spirea is a mounded, medium height and spread shrub that can form the bones of a perennial bed. The leaves are yellow-green and they put out small pink flowers. Some varieties, such as Spirea japonica ‘Froebelii’, have showier pink umbels over clear green leaves. The bridal wreath spireas are spreading in form and have sprays of white blossoms.

Dogwood (Cornus). Dogwood trees are common in some parts of the country, but perhaps not as well know is the dogwood shrub.

Dogwood shrubs are reliable in most of Canada. The dwarf shrub, Cornus sericea ‘Farrow’ has dark red twigs that make a great show against a winter landscape. It maxes out at four to five feet wide and tall. Tolerant of half shade, the foliage is dark green in summer and turns red in fall. C. sericea ‘Bud’s Yellow’ is larger, six to eight feet, and it sports bright yellow twigs.

There are several other varieties worth looking at. The variegated C. alba ‘Cream Cracker’ is four to five feet. Its leaves are green with golden margins on new foliage, fading to cream as the season progressions. C. alba ‘Jefreb’ is small, at three to four feet, and has coral red bark and crisp green summer leaves that run red in fall.

C. alba ‘Ivory Halo’ displays white margined green leaves and reached four to five feet in height.

Bridalwreath spirea.

Pulmonaria, milky and spotted.

‘Goldmound’ spirea.

Silver variegated’ dogwood.

Creeping thyme.

Woolly thyme.

Ajuga flowers.

Groundcovers

Groundcovers are plants that grow low and spread to cover a wide patch of bare ground. The thing that makes them groundcovers—their ability to spread—also makes them difficult if the wrong choice is made or if they are too happy.

Fortunately, there are a number of well-behaved plants that can take up the groundcover challenge without becoming rampant. There are also some that should be avoided unless you really know what you are doing.

One more word of caution: groundcovers can take some time to establish so don’t get fooled by that recently planted goutweed that seems to be quite docile—in a couple of years, it will spring to life and overpower everything in its path!

Lungwort (Pulmonaria). This plant used as a specimen or in masses as a groundcover is a winner in a shady spot or in sunshine. The common spotted variety lights up the shade and, in springtime, it blooms early with pretty pink or blue or white flowers. When blooming is over the flower stems die back; pull them to keep the clumps looking tidy. It grows six to eight inches in height with big, broad, fuzzy leaves.

Thyme (Thymus). Thyme is a good groundcover. It is fragrant and it is easy to keep under control. Creeping thyme is covered in little mauve flowers. It is less than three inches high. Bees love it when in bloom and it is a great herb for flavouring. It prefers it dry, gritty soil, doing well as a filler between pavers or stepping stones, and it enjoys full sun, but woolly thyme will grow in partial shade. There are many varieties.

Bugleweed (Ajuga). This ground hugger has shiny evergreen leaves that can be green or chocolate brown. It is a member of the mint family so you know it will spread but Zone-3 gardeners may find it easier to keep under control. It is mat forming and sends up little spires of purple, sometimes white, flowers. It typically prefers shade so is a little less rampant in sun.

Creeping phlox.

Creeping phlox.

Bishop's goutweed.

Creeping phlox (Phlox subulata and P. stolonifera). One of the prettiest groundcovers is creeping phlox, also known as moss phlox. Growing just four to six inches tall, it is a mass of pink, red, white, blue or mauve flowers in spring. Full sun is best for this lovely and it prefers well drained soil. Forms a mat.

Lamb’s ears (Stachys). Kids will love the soft strokeable lamb’s ear. Their tiny pink, white or mauve flowers appear in summer. For the best groundcover, look for the dwarf varieties growing about four inches tall. Silvery gray, it makes a nice contrast with greener plants. Lamb’s ear is happy even in part shade.

Groundcovers and others to avoid

While no plant is evil, some can be more determined than others, and much depends on the zone you live in. What might be manageable in Zone 3 could be a nightmare in a warmer zone. Be sure to consult with the local garden centre before making a final choice.

Among the biggest offenders even in cooler zones is bishop’s goutweed (Aegopodium podagraria), that lovely variegated green and white plant that has lovely lace flowers, but which will overtake most competitors. Some lamium, Lamium galeobdolon is the worst, can also be a vicious spreader. Both these plant are taller than the ground hugging types or ground covers.

Not a groundcover technically is creeping bellflower. Very persistent, it will be your friend or enemy for life, whether you like it or not!

Striped ribbon grass is a menace, very hard to control. And while we all love the smell of lily of the valley, and she will grow in shade, she travels as fast

Pink creeping phlox flowers.

Lamium galeobdolon.

Lamb's ear.

Lamb's ear in blossom.

Englemann ivy.

Lonicera ‘Dropmore Scarlet’.

Clematis ‘Jackmanii’.

Englemann ivy. Lonicera ‘Dropmore Scarlet’. Clematis ‘Jackmanii’. as she can toward to the sunny place where you don’t necessarily want her.

These plants grow either “stoloniferously”, meaning that the plant roots travel via over ground stems that send down roots when they touch the earth at stem junctures (such as strawberries) or rhizomatically, travelling with the aid of under the surface roots that send up new plants from root junctions.

Vines

Gardeners often dream of lovely vines draping over fences or arbours or along trellises.

Englemann ivy (Parthenocissus quinquefolia var. englemannii). When looking for the big-leafed vine that often covers fences, garden centres often sell Virginia creeper without telling the buyer that is just what this vine does: it creeps and can be tough to deal with and it can become invasive. At best, it needs support and help to climb a vertical structure.

The plant to buy is Englemann ivy, a variation of Virginia creeper, which has clinging feet and doesn’t need any special help to climb a wall. It turns a deep rich red in fall.

Honeysuckle vine (Lonicera) ‘Dropmore Scarlet’. If you love hummingbirds then this honeysuckle vine is a sure magnet for these tiny birds. It does need a trellis to support its twining stems, but its pretty reddish-pink flowers make the trouble worth it.

Clematis ‘Jackmanii’. The easiest and most reliable big flowered clematis is the purple ‘Jackmanii’. It likes morning sun and cool roots, something you can accomplish by planting something to add shade at the lower level just in front of the vine or add two or three inches of mulch at the base of the plant. It too is a twiner so will need a trellis to climb on.