western canada’s only gardening annual

A non-profit publication dedicated to the advancement of horticulture in the Prairies

81ST ANNUAL EDITION

WESTERN CANADA’S ONLY GARDENING ANNUAL

ACKNOWLEDGMENTSThe Prairie Garden is a non-profit publication produced by a volunteer com-mittee. We greatly appreciate the support toward publication costs that we have received from our sponsors, the companies below, who share our inter-est in prairie horticulture. Please support them in turn.

Copyright © November 2019 The Prairie Garden Committee, Winnipeg, Manitoba, Canada

All rights reserved. The material in this publication is for informational purposes only. The views expressed by contributors are not necessarily those of The Prairie Garden Committee. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by The Prairie Garden Committee is implied. The reader assumes all risk for the implementation of instructions and recommendations. The contents of this publication may not be reproduced or used in any fashion without the written consent of The Prairie Garden Committee, other than short excerpts as may appear in book reviews and literature citations.

ISBN 978-0-9939559-5-2

Published by The Prairie Garden CommitteeP.O. Box 21043Winnipeg, MB R3R 3R2www.theprairiegarden.com

Chair: Ian WiseVice-Chair: Darlene BeltonGuest Editor: Maureen KraussEditor: Linda DietrickTreasurer: Maggie Shen Bookkeeper: Monique GraboskiSecretary: Suzanne SimpsonSales: Rita Campbell and Joshua PearlmanMarketing: Rita CampbellSocial Media: Sarah PiercyWebsite: Tom NagyCommittee Members: William Dowie, Tiffany Grenkow, Lynne McCarthy, Susanne Olver, Brent Poole, Sandra VentonAssociates: Jeannie Gilbert, Warren Otto, Andy TekauzRegional Representatives: Sara Williams (Saskatoon, SK), Melanie Mathieson (Thunder Bay, ON), Jane Reksten (Calgary, AB)

Design: Ninth and May Design Co.

Photo Credits: See page 181.

Printed in Canada: Friesens CorporationForest Stewardship Council certified printerPress – all inks are vegetable based

Price: $17.95 per copySpecial quantity prices available to horticultural societies, garden clubs, commercial outlets, etc. For past editions and general sales information, see page 183.

On the cover: Black swallowtail butterfly on a black-eyed susan. Photo by Kelly Leask (PrairieOriginals.com).

BUR OAK SPONSORS (BACK COVER)

JEFFRIES NURSERIESP.O. Box 402, Portage la Prairie, MB R1N 3B729053 Trans-Canada Hwy #1204-857-5288 • [email protected] jeffriesnurseries.com

LINDENBERG SEEDS803 Princess Ave., Brandon, MB R7A 0P5204-727-0575 • (Toll free) 1-888-714-4542 [email protected]

PRAIRIE ORIGINALS Box 25, Grp. 310, RR3, Selkirk, MB R1A 2A827 Bunns Rd., Selkirk MB. 204-785-9799, toll free [email protected]

ST. MARY’S NURSERY & GARDEN CEN-TRE2901 St. Mary’s Rd., Winnipeg, MB R2N 4A6204-255-7353 • [email protected] stmarysnurseryandgardencentre.ca

T & T SEEDSP.O. Box 1710, Winnipeg, MB R3C 3P67724 Roblin Boulevard, Headingly, MB 204-895-9962 • [email protected]

TREE TIME204-9366 49 St. NW, Edmonton, AB T6B 2L7(Toll free) [email protected] treetime.ca

WOLF WILLOW SPONSORS (LAST PAGE)

AUBIN NURSERIES LTD.P.O. Box 1089, Carman, MB R0G 0J0 1.5 miles east of Carman on Hwy 3204-745-670 [email protected]

JENSEN NURSERIES2550 McGillivray Blvd Oakbluff, MB R4G 0B3 204-488-5042 • [email protected]

HTFC PLANNING + DESIGN500 – 115 Bannatyne Ave. E.Winnipeg, MB R3B 0R3204-944-9907 • [email protected]

KACKENHOFF NURSERIES1317 Hwy. 75, St. Norbert, MB R3V 1L4204-269-1377 • [email protected]

THE LILY NOOKP.O. Box 846, Neepawa, MB R0J 1H0204-476-3225 [email protected]

SAGE GARDEN GREENHOUSES3410 St. Mary’s Road, Winnipeg, MB R2N 4E2204-257-2715 • [email protected]

SHELMERDINE GARDEN CENTRE7800 Roblin BoulevardHeadingley, MB R4H 1B6204-895-7203 • [email protected]

6 From the Guest Editor

7 From the Editor

THEME: INSPIRED BY NATURE

8 The New Naturalism in the Prairie Garden Maureen Krauss

11 Layers of a Designed Plant Community

12 Inspired by Prairie Janet Davis

18 The New Naturalism: Recommended Resources Linda Dietrick

21 Inspired by the North American Prairies Lianne Pot

25 Supernaturalistic: The New Perennial Pond Garden Tony Spencer

30 Matrix Perennials for the Northern Prairies Linda Dietrick

34 Perennial Structure in Gardens Eileen Rosen

38 Your Garden – Naturally Chris Penner

42 Good Plant, Bad Plant: Native and Non-Native. Is it That Simple? Roy Diblik

45 What Grew Here Before? The Patterns of the Prairies Marika Olynyk

50 The Prairie Landscape in Fiction Linda Dietrick

52 Fifty Years Ago in The Prairie Garden: The Blooming Desert Lawrence A. Stuckey

55 Review of The Sands of the Assiniboine Delta by Sheldon McLeod Linda Dietrick

56 Hardy Cacti for the Northern Prairies Ernie Brown

62 Cupfuls of Sunshine: The Prairie Crocus Jeannette Adams

64 Native Grasses for Prairie Landscapes John P. Morgan

66 My Prairie Patch: Observations from a Native Plant Garden Kelly Leask

70 Grow a Row for Wildlife: Creating Sustainable, Biodiverse Hedges Sheryl Normandeau

74 Two Shovels, a Wheelbarrow, and the Genesis of an Idea Lynne and Rebekah Vickery

78 Prairie Pollinator Patch June Flanagan

81 Earth-Friendly Gardening with Native Plants Kelly Leask

84 Gardening with a Difference Karen Loewen

87 Planting for the Climate Vanessa Corkal with Ryan Smith

91 Help a Bee in Need: Create Some Habitat Sarah Semmler

CONTENTS95 Native Plant Diversity in a Rooftop Prairie Garden Dorothy Tuthill

99 Henteleff Park: An Urban Gem Marilyn Latta

103 The Wildflower Project Matt Wildenauer

108 Winnipeg’s Niakwa Trail Rain Garden is for the Birds Michele Kading

112 Rooted in Clay Anna Thurmayr and Dietmar Straub

113 Have You Considered a School Garden? Suzanne Simpson

117 A Tale of Two Transplants: Simple Guidelines for Protecting Nature Barret Miller

119 Ladyslipper Orchids (Cypripedium) for Your Garden Sandra Venton

121 Medicines Inspired by Nature: The Doctrine of Signatures Colin Briggs

125 Telling Stories with Bonsai Trees Joe Grande

GENERAL

129 Abbott’s Sphinx Moth: The Deceptive Garden Intruder Ian Wise

131 How Plants Use Microbes to Help them Extract Nutrients from Soil James White

134 Gardening for Specialist Bees: Sunflowers Jason Gibbs and Emily Hanuschuk

137 The Magic of Mushrooms: Understanding and Working with Our Fungal Allies Tom Nagy

140 Crisis in the Prairie Urban Forest Rick Durand

144 The Cottony Ash Psyllid Ian Wise

147 The Rocky Mountain Locust: Extinction of a Prairie Colossus Ian Wise

150 What Do Your Plants Want? Tips to Ensure Their Happiness and Yours Susanne Olver and Veronica Larmour

153 Buy Now – Regret Later Rita Campbell

157 Know Thine Enemy (Weeds) Tiffany Grenkow

161 The Secrets to Three Seasons of Easy Greens Tiffany Grenkow

165 Killarney Demonstration Farm Gordon Goldsborough

169 East Meets West: The Story of the China Roses Barbara Shields

173 Bob Bors and Rick Sawatzky Receive the 2019 Stevenson Award Sara Williams

177 In Memory of Ken MacDonald (1956-2018) Colleen Zacharias

179 Remembering Dr. Jennifer Shay (1930-2018) Gordon Goldsborough

6 The 2019 Prairie Garden 7

FROM THE EDITOR

This year’s issue focuses on how we as gardeners can take a cue from nature in everything from design to plant choice to ongoing care, so as to create gardens that are not only beautiful, but also more resilient, less work to maintain, and friendli-er to all living things – a little bit like nature itself. Something in us seems to yearn for the wildness of the natural world, yet each of us also feels the need for a greater or less-er degree of order. And gardening seems to be about finding a balance,

FROM THE GUEST EDITOR

Where does inspiraTion come from? This issue of The Prairie Garden explores how we as gardeners and designers are inspired by nature. In-spiration is both powerful and moti-vational. It can come from a parent, a teacher, or an Elder. It is a sponta-neous evocation that transcends our understanding, taking us beyond the usual and into new possibilities. When we embrace the natural world by delving in with all our senses, even within the limits of a small gar-den, life can be transformed.

My childhood home was brim-ming with possibilities for being inspired by nature, where the clas-sic garden plantings of lilac bush-es, peonies, and rhubarb patches were repeated over and over again throughout the neighbourhood. Zin-nias and cosmos lined a white picket fence. There was an elm tree in the backyard perfect for climbing, a cra-bapple tree that would yield a shelf full of jewel-like jars of jelly each au-tumn, and a Dropmore honeysuckle vine on the chimney that attracted hummingbirds. The requisite holly-hocks flanked both sides of the back

lane, flashing columns of colour as you sped by on your bicycle. These colours, shapes and scents trans-formed me and are indelibly printed in my memory.

I have one early recollection that stands out, when the moment slowed and I was encouraged to open my eyes wider to observe, and ultimate-ly be inspired by, nature. It came in the form of a visit to my aunt at her workplace where she practised as a seed analyst for the federal govern-ment. I recall sitting on bended knees to peer through her microscope at seed samples, barely visible with the naked eye, sandwiched between tiny glass plates. Flat and shiny, round and ovoid, hairy and spiny, each seed possessed its own natural adapta-tion for success to catch the wind or be distributed by a passing animal. In the cold of the germination room, trays of tiny green sprigs unfurled to be more closely analyzed. Here I witnessed the infinitely unique and secret world of seeds – something I think about annually as I open a fresh envelope of hope for the coming growing season.

Inspiration is good for us, not only for our personal well-being, but also for bigger ambitions. It can give us a greater sense of purpose and a deeper appreciation and caring for nature. My hope is that this edition of The Prairie Garden will offer our readers their own reason to slow the moment to be inspired, and re-in-spired, by nature.

—Maureen Krauss

engaging thoughtfully with nature, and applying art and technique to create something of our own from its material.

This issue includes articles on the planting principles of renowned designers like Piet Oudolf who are strongly influenced by our own prairie landscapes; on our connec-tion to the natural history of our region; on hardy native plants that are perfect for gardens; on garden-ing techniques that respond to the new realities of climate change; and on interesting public and private gardens inspired by nature. As al-ways, you will also find articles on all kinds of other gardening topics.

We acknowledge that The Prai-rie Garden is edited and printed on Treaty One land, the traditional territory of the Anishinaabe, Cree, Dakota, and Oji-Cree Nations, and in the homeland of the Métis Nation.

—Linda Dietrick

A robin eating mountain ash fruit at the Niakwa Trail Rain Garden. See story on p. 108.


in recenT monThs I have been read-ing books and articles by the design-ers, authors, and bloggers of the New Naturalism (or New Perennialism) movement and finding myself silent-ly nodding in agreement, circling words, concepts, and practices that speak to what I enjoy and value in naturalized landscapes. I have also had the opportunity to visit some of the most iconic projects of this new perspective, including the High Line in New York. There I intuitive-ly understood that the wildness I witnessed before me within the ur-ban setting was highly intentional and masterfully designed. There is balance between order and disorder, creating the appearance of nature’s spontaneity while carefully orches-trating the habits and architectural form of plants. Now more than ever, I see how this approach not only feeds our soul, but is also the right way forward in nurturing biodiver-sity, managing water, and building resilient and rich garden habitats.

Over twenty-five years ago, I had the good fortune to work on establishing a small wildflower garden at Fort Whyte Centre (now FortWhyte Alive). The garden was

designed as a demonstration and teaching tool for visitors to learn more about native plants and the benefits of using them in the home landscape. The plant material was purchased through one of the very few local suppliers at the time, Prai-rie Originals. We relied heavily on the expertise of its owner Shirley Froehlich to guide in the plant selec-tion. Logically, we knew there should be short plants and tall plants, with early, mid- and late-season blooms for colour. I don’t recall thinking much about filler plants or winter structure, important considerations for designers today. At the time, in-corporating grasses was a hard sell because their inclusion as a plant of choice in the home garden was just emerging as a trend. A few years later, a small bur oak (Quercus mac-rocarpa) was planted in the corner of the garden plot, which in hindsight was a brilliant addition. As with any garden evolution, there was forethought and planning combined with a healthy dose of good and bad fortune and complete serendipity.

In the early years, tending this nascent garden had its highs and lows, but it was never without

valuable lessons. Some species like showy goldenrod (Solidago nemor-alis) proved highly prolific, while the blue-eyed grass (Sisyrinchium montanum) never flourished. The pussytoes (Antennaria parvifolia) happily multiplied. In time, the best plants for this dry and heavy soil site, which by the way was a former clay mine, naturally sort-ed themselves out – some thriving, others disappearing. I realize now that knowing more about the eco-logical principle of layering plants would have made for greater suc-cess in the beginning. In what was essentially a living exhibit, there was also a desire to display as many different plant species as possible. Again, this was something that in principle New Perennialist gardens avoid: focusing too much on individ-ual plants and not enough on plant communities appropriate to the site. And in the prairie purist at-tempt to design with native plants only, there was no intermingling of similar non-native cultivars, which could have added some wow factor to the form and colour of the exhibit, thereby possibly persuading more early adopters to plant natives.

In practice, and as contempo-rary writers suggest, the new nat-ural style implies or suggests a re-al-world habitat. It does this not by a natives-only planting approach, but by creating plant communities that, while they allow for non-natives, still hint at actual natural environ-ments. I believe this to be the secret to why we are drawn to these land-scapes. They offer something of the wild and unknown, but with a touch of the familiar.

FortWhyte’s wildflower gar-den blooms on nearly three decades later, with the early-season dis-play of three-flowered avens (Geum triflorum) and Canada anemone (Anemone canadensis), the summer stalwarts wild bergamot (Monar-da fistulosa) and swamp milkweed (Asclepias incarnata), and feathery asters in the fall. It feels right on many levels, greater than the sum of its parts, which is the essence of the New Naturalism movement.

It is interesting and perhaps surprising to prairie gardeners that the contemporary landscapes of New Perennialists like Piet Oudolf include many of our own hardy na-tive perennials and grasses in their

BY MAUREEN KRAUSS

Formerly with Winnipeg’s FortWhyte Alive, guest editor Maureen Krauss is a principal with HTFC Planning & Design. Bringing together business, non-profit, and government to develop green projects, her work aims to inspire healthier communities and interpret the natural world.

THE NEW NATURALISM IN THE PRAIRIE GARDEN

The Wildflower Garden at FortWhyte Alive, Winnipeg


designs. For example, Joe Pye (Eu-trochium syn. Eupatorium macu-latum), giant hyssop (Agastache foeniculum), purple and prairie coneflowers (Echinacea angustifolia, Ratibida columnifera), black-eyed susan (Rudbeckia spp.), blazing star (Liatris spp.), Culver’s root (Veroni-castrum virginicum), and blue ver-vain (Verbena hastata) are widely used and look fantastic rising up from a sea of grasses.

As you will learn from other ar-ticles in this book, there are many reasons why the native plants of the prairies are a good choice for gar-dens. It is no accident that they have become an international design trend. As New Naturalist designers have shown, they can be used to-gether with more traditional non-na-tive cultivars to create an image of beautiful wildness in a world where that quality sometimes feels needed.

“My biggest inspiration is nature. I do not want to copy it but to recreate the emotion. What I try to do is build an image of nature.”

—PIET OUDOLF (Designing with Plants, Timber Press, 1999)

Piet Oudolf in his garden at Hummelo, the Netherlands. Portrait photo © Bart Heynen.

In natural environments, an integrated community of plants covers the soil, with each plant finding its place and function in a range of levels or layers. Landscape designers associated with the New Perennialist move-ment conceptualize their plantings in terms of these natural, intermin-gled layers. For example, Thomas Rainer and Claudia West (Planting in a Post-Wild World, Timber Press, 2015, p. 173) define these three layers:

• Structural Layer (10–15% of plants): taller plants with persistent presence, e.g. Joe Pye, Culver’s root, giant fleeceflower, big bluestem, shrubs, trees

• Seasonal Theme Layer (20–40%): plants with seasonal presence, e.g. spring bulbs, salvia, monarda, coneflowers, asters

• Matrix or Ground Cover Layer (40–60%): shorter grasses and low perennials, e.g. prairie dropseed, blue grama, pussytoes, sedum, or in shade: sedges, wild ginger, Solomon’s seal.

—L.D.

LAYERS OF A DESIGNED PLANT COMMUNITY

STRUCTURAL LAYER

SEASONAL THEME LAYER

MATRIX or GROUND COVER LAYER

Graphic by Shannon Loewen


1. Eastern red columbine (Aquilegia canadensis) with golden alexander (Zizia aurea): This is a lovely pairing for a sunny or lightly shaded, humus-rich area with moist soil, thus mimicking the prairie glades, woods and moist, rocky meadows that both species prefer in the wild. Flowering in mid-late spring, the lacy, yellow zizia umbels softly frame the brilliant red columbine flowers. Black swal-lowtails use zizia foliage as larval food and hummingbirds, bees and butterflies nectar on the columbine. Both will happily self-sow in time.

2. Black-eyed susan (Rudbeckia hirta) and wild beebalm (Monarda fistulosa): As a biennial, common black-eyed susan needs to be sown over two years to ensure flowering each summer, when its familiar gold blossoms will light up the natural-istic garden for several weeks. Wild beebalm (or bergamot), on the oth-er hand, is reliably perennial and a prolific self-seeder. It’s also one of the prairie’s best wildlife plants, attracting butterflies, moths, hum-mingbirds and, of course, the bees that lend it its common name. Both species tolerate poor soil and are drought-tolerant.

BY JANET DAVIS

Janet Davis is an award-winning Toronto photographer, writer, and blogger. In her three decades as a freelancer, she’s been a weekly gardening columnist, an online garden editor, and the author of hundreds of magazine stories. Her popular blog is www.thepaintboxgarden.com.

INSPIRED BY PRAIRIE1

2

3

in my Three decades of freelance garden writing, I’ve often written or blogged about “prairie,” wheth-er it’s a visit to Wanuskewin Heri-tage Park in the city of my birth, Saskatoon; the new and delightful Legacy Prairie at Niagara Botani-cal Garden near Niagara Falls; the Suzanne Dixon Prairie at Chica-go Botanic Garden; or any number of prairie-like meadows designed by Piet Oudolf for Chicago’s Lurie

Garden or New York City’s Highline or my own local Toronto Botanical Garden. Natural prairies and their designed reproductions have a spe-cial appeal for me and I take note of beautiful, effective prairie-style plant combinations that would work in any naturalistic garden. Here are nine of my favourites, including mostly native perennials, roughly in the order of bloom.


3. Hoary vervain (Verbena stricta) and blanket flower (Gaillardia x grandiflora): In the wildest, driest part of my country garden on Lake Muskoka north of Toronto, I grow a hand-ful of tough, hardy perennials that need no coddling, nor any irriga-tion beyond rainfall. Two that look particularly fetching together are purple vervain and red cultivars of blanket flower such as ‘Burgundy’. One caveat with blanket flower is that it needs deadheading to stay in bloom; provided spent blossoms are removed, plants will flower from early summer to autumn. Both are good pollinator plants.

4. Swamp milkweed (Asclepias incarnata) with ‘Blue Fortune’ anise hyssop (Agastache hybrid):Plant these two summer-bloom-ing natives together in a sunny spot in moisture-retentive soil and watch the butterflies and bees ar-rive in droves. Monarch butterflies, of course, use swamp milkweed as a larval food, but they also love to forage on the anise hyssop, an award-winning, licorice-scented hybrid of native Agastache foenicu-lum and Korean Agastache rugosa. It starts out a deep indigo-blue and fades to light violet. Despite swamp milkweed’s common name, it does just fine in an irrigated garden.

5. Purple coneflower (Echinacea purpurea) with dense blazing star (Liatris spicata): This duo represents two of the most recognizable and easy-going sum-mer-blooming prairie natives. Each attracts loads of bees and butterflies

and, later in the season, the cone-flower seedheads offer food for gold-finches and other birds. Both peren-nials enjoy full sun and adequately moist, rich soil. One of the western species of blazing star, L. punctata or L. ligulistylis, could be substitut-ed.

6. Culver’s root (Veronicastrum virginicum) with spotted Joe Pye weed (Eutrochium maculatum):Late summer perennials that ex-tend the flowering season are in-valuable – for gardeners and for pollinators. The shimmering, white spires of Culver’s root are wonder-ful bee lures, and the towering, car-mine-red blossoms of spotted Joe Pye weed attract butterflies and bees while adding a dimension of height to the garden. Both species are na-tive to marshes, rich fens and moist meadows, so they require constantly moist to wet soil in full sun, making them ideal for a rain garden.

7. Sneezeweed (Helenium autumnale) with summer phlox (Phlox paniculata): This late summer pair shares a love for moist-to-wet, rich soil and sun-ny to partly shaded locations where they will put on a flowering show for many weeks. Being insect-pollinat-ed (bees love it), sneezeweed does not cause allergies; rather its common name comes from its traditional use for making snuff. And old-fashioned, fragrant phlox is now available in many mildew-resistant cultivars that make better garden plants, but it’s worth noting that mildew prob-lems can be mitigated by providing

4

5

6


one of The mosT sTriking character-istics of naturalistic gardens in the style of Piet Oudolf or other New Pe-rennialists is that there is no open soil. Just like in nature, plants fill every square inch in a densely inter-mingled community of species. Ide-ally, that leaves no room for weeds. Undesirable or invasive species can’t compete for soil, moisture, and light in an area that is already well col-onized. At the same time, and per-haps more importantly, having no bare spots between plants makes

the whole landscape look more har-monious and unified.

Many plantings in the New Pe-rennialist style resemble meadows or prairies, where green and lat-er tan-coloured grasses serve as a backdrop to larger, more colourful perennials throughout the season. While the flowering perennials may appear to dominate the design, they are relatively few in number. In terms of sheer volume, it is the grasses that actually dominate the planting, even though they have

a much lower impact visually. Be-cause they form a sort of foundation or surrounding environment for the higher-impact elements, the grasses are known as matrix plants.

Matrix plants are more or less what we have traditionally called ground covers. The advantages of these are well known. Like a living mulch, they suppress weeds and shade the ground, thus helping to retain moisture. As long as they don’t out-compete their neighbours, they have always been a good idea. From a design standpoint, they also serve the purpose of softening and unifying the total design. Not just grasses, but other ground-covering perennials can function in this way.

How much of a planting should be matrix? In a natural prairie, as much as 80% of the plants may be grasses. In other settings like the understory of woods, it’s also most-ly green, with only sporadic flowers. In gardens, on the other hand, we expect to see more variety and co-lour. Therefore designers generally plan for matrix plants to make up about 40–60% of the total number of plants.

For a grass matrix, designers tend to favour the shorter, warm-sea-son grasses of our own mixed- and tall-grass prairies, including:

• Side-oats grama (Bouteloua curtipendula)

• Blue grama (B. gracilis)• Switch grass (Panicum

virgatum)• Little bluestem (Schizachyrium

scoparium)• Indian grass (Sorgastrum

nutans)

• Prairie dropseed (Sporobolus heterolepis).

All of these are well-behaved, clumping grasses with a long season, at their peak in late summer and turning a lovely straw colour in fall. Two cool-season species may also be used to provide earlier tufts of green and seed heads before the other, lat-er grasses come into their own:

• Tufted hair grass (Deschampsia caespitosa)

• June grass (Koeleria macrantha).

Taller grasses like big blue-stem (Andropogon gerardii) and the non-native Karl Foerster feather reed grass (Calamagrostis x acuti-flora ‘Karl Foerster’) are too big to serve as matrix plants, but they may appear as structural or accent plants in larger spaces.

Apparently Piet Oudolf really got to know our prairie grasses and perennials when he began design-ing the Lurie Garden for Chicago’s Millennium Park in 2001. Needing a local nursery to partner with, he was introduced to Roy Diblik of Northwind Perennials in Wiscon-sin. Roy, who had been growing re-gional natives for years, showed Piet his nursery, and their exchange of ideas and seeds has continued ever since (see Roy’s article in this issue). Oudolf’s countrywoman Lianne Pot, whose ornamental grass nurs-ery hosts the Netherlands’ official collection of grass species, has also fallen in love with prairie grasses and perennials. In the early 2000s, after travelling to the US and see-

BY LINDA DIETRICK

MATRIX PERENNIALS FOR THE NORTHERN PRAIRIES

This grassland section of Piet Oudolf’s High Line in New York uses a matrix of prairie dropseed (Sporobolus heterolepis) and switch grass (Panicum virgatum).


ing them growing in situ, she add-ed them to her nursery and display garden (see her story in this issue). A prairie grass matrix figures in Oudolf’s most recent public planting designs in the US, both opening in 2020. The Delaware Botanic Gar-den in Dagsboro features prairie dropseed, while the Belle Isle Gar-den in Detroit features blue grama along with a Eurasian native, pur-ple moor grass (Molinia caerulea, zone 5).

As noted, matrix plants do not have to be grasses. Most private gardens lack the large spaces with full-sun exposure that lend them-selves to prairie-style plantings, and it is difficult to miniaturize a prairie. Therefore, in smaller sunny areas, especially if you have shrubs that would be visually overwhelmed by grasses, it may be better to plant a matrix of shorter, more tradition-

al sun-loving ground covers like sedum, thyme, creeping phlox, or our native pussytoes (Antennaria parvifolia), prairie sage (Artemisia ludoviciana), and three-flowered av-ens (Geum triflorum).

If you have buildings, fences, and trees on your property, as most of us do, then you also have shade. And the prairie grasses have not evolved to tolerate shade. To find matrix plants for shady areas, we have to look to other natural plant communities for models: open wood-lands (here on the prairie, usually near rivers) and the boreal forest. Their understories harbour a num-ber of native plants that will effec-tively cover the ground in shady ar-eas of the garden, including:

• Sarsaparilla (Aralia nudicaulis)• Wild ginger (Asarum

canadense)

• Wild strawberry (Fragaria glauca)

• Star-flowered Solomon’s seal (Maianthemum stellatum syn. Smilacina stellata)

• False and two-leaved Solomon’s seal (M. racemosum, M. canadense)

• Solomon’s seal (Polygonatum biflorum)

• Western Canada violet (Viola canadensis)

All are fairly vigorous spread-ers, though not invasive like gout-weed, so keep an eye on them until you see how they behave in your yard.

In Germany, New Perennialist designers have developed perennial mixes for shady plant communities that use the same matrix principle as the prairie-style plantings. Many of the shade-loving ground covers in these mixes are perfectly hardy in zone 3 or 4, including:

• Bergenia (Bergenia cordifolia)• Brunnera (Brunnera

macrophylla)• Sweet woodruff (Galium

odoratum)• Cranesbill (Geranium spp.)• Deadnettle (Lamium

maculatum)• Fleeceflower (Persicaria affinis)• Lungwort (Pulmonaria spp.)• Perwinkle (Vinca minor)• Barren strawberry (Waldsteinia

ternata).

In my front yard, where mature boulevard trees take up much of the available moisture, I have found that barren strawberry, periwin-

kle ‘Illumination’, and fleeceflower ‘Dimity’ are remarkably tolerant of dry shade. I also recommend the low native shrub bearberry or kin-nikinnik (Arctostaphylos uva-ursi) for this situation.

Another promising genus for matrix plantings in shade is Car-ex or sedge. Sedges are grasslike plants that grow in all kinds of set-tings, including dry shade under trees. Where grasses cannot grow, sedges produce a similar soft, fluffy matrix for other perennials. Roy Diblik recommends a number of car-ex species for home gardeners and almost always includes them in his shade plans (see The Know Main-tenance Perennial Garden, 2014). Although my province, Manitoba, is home to over 120 species of sedge, only one appears to be available in the local nursery trade, Bebb’s sedge (Carex bebbii), which prefers moisture and sun. Two shorter prai-rie natives, Pennsylvania sedge (C. pensylvanica) and ivory sedge (C. eburnea), tolerate dry shade and are used to underplant birch trees in Oudolf’s design for the High Line. Western Canadian nurseries should start producing more sedges for gardeners to try. These hardy, ver-satile plants have now become quite trendy south of the border.

For more information on hardy grasses, see the 2015 issue of The Prairie Garden featuring Grasses and Succulents. To learn more about sedges and shade-loving groundcov-ers, see The Prairie Garden for 2018 featuring Shade, which includes an extensive plant list at the back.

Wild ginger (Asarum canadense) is an excellent native matrix perennial for moist or dry shade.

western canada’s only gardening annual

Documents