DROUGHT TOLERANT LANDSCAPING A Resource for Development January 2012City Planning
January 2012 DROUGHT TOLERANT LANDSCAPING A Resource for Development1-2 Introduction Drought Tolerant Landscaping 3-4 Commonly Planted Drought Tolerant Landscaping Species5-7 Native Southern Ontario Drought Tolerant Landscapes Carolinian Forest Landscape Oak Savanna Landscape Tall Grass Prairie and Meadow Landscape 8-11 Cultural Drought Tolerant Landscapes Butterfly Landscape Rock Garden Landscape Pre-Confederation Pioneer Landscape Hedgerow Landscape Invasive Species12-13 References
1 Introduction Drought Tolerant Landscaping The new Toronto Green Standard Tier 1 requires a minimum of 50 percent water efficient landscape species and 50 percent native species to be used in landscaping for all development within the City of Toronto. The selection of drought tolerant and native plant material in development is important as drought tolerant plants reduce the demand for potable water in landscaping, requiring less maintenance and bringing ecological diversity and seasonal interest to the landscape. This resource has been created by city staff to assist city staff and professionals working in the development industry in finding drought tolerant planting material to meet the T.G.S. requirements. Southern Ontario encompasses a great richness of ecological diversity which includes a large variety of native drought tolerant species and landscape types. Encouraging development projects to include native drought tolerant species within the landscape design increases species biodiversity, helping enhance the unique, yet fragmented natural heritage systems (such as the Oak Savanna, Carolin- ian Forest, Tall Grass Meadow) within the City of Toronto. Species native to Southern Ontario have adapted to the local environmental conditions over thousands of years and thus are best suited to the local soil and climate conditions. Because of this adaptation, local native species are more adaptive to local drought and disease, requiring less watering, maintenance and replacement in the long term. Planting native species also brings seasonal diversity in color and interest to a landscape and provides the appropriate species for food and shelter to many local insects, birds and animals, creating anima- tion in the landscape and supporting local wildlife populations. The key to reaping the benefits of drought tolerant native species is two fold: assessing the appropri- ate landscape planting material for the conditions of the site and the initial establishment of the plants within the site during the first year. Drought tolerant plant material must have soil, sun and moisture requirements that closely match the conditions of the site. Once planted, the landscape plantings require deep and thorough watering on a consistent basis within the first year to establish the plant’s root systems. Drought tolerant and native plantings can only be drought tolerant after the planting’s root systems have established.
2 Introduction Drought Tolerant Landscaping One of the challenges of planting, especially native species, on development sites is the conditionof the soil on site. At many development sites the original soils have been disturbed or in manycases stripped of their organic layers, filled with construction debris (altering the pH of the soil) andcompacted by heavy machinery. These conditions make it very difficult for plant roots to grow andestablish without access to air and water pockets that would be normally present in a healthy soil en-vironment. In addition, many landscape development sites are situated above underground concreteparking slabs where disturbed, off site soil is introduced in minimal amounts and requires constantirrigation and maintenance to maintain a supportive environment for plant growth.Many species native to Southern Ontario have adapted to specific soil pH and composition conditionswhich may not be available on development sites and as such, should not be selected for plantingon development sites with highly disturbed soil conditions. Selection of native or non native plantmaterial needs to be balanced between picking appropriate plants which will grow in the existingsoil conditions and providing native plant diversity to the site. When designing planting beds withdrought tolerant and native plant material, both formal and informal planting layouts should beconsidered. In the context of an urban environment a formal, geometric planting is as appropriateand can provide as diverse a species selection as an informal ‘naturalized’ planting.The following two pages list commonly planted native and non-native landscape species which aretolerant to drought and nutrient poor soils on moderately disturbed sites. The species planting listsare followed by a planting list of local native and cultural drought tolerant landscape types. Theseplanting lists should be used as a non exhaustive list, as a catalogue rather than a cookbook forselecting drought tolerant planting.
3 Commonly Planted Drought Tolerant Landscaping Species NOTATIONS (i) invasive species, not to be planted near natural ravine areas. (cs) commonly substituted species, carefully select appropriate species (h) hybrid species, genetic hybrid of native and non native species (nc) native canadian species, native to Canada, not to Southwestern Ontario (*) Black Walnut juglone toxicity, plant walnut associated species in understoreyTREES SHRUBSDeciduous Trees Red Maple Turkish Hazel Shrubs Meadowsweet Spirea (cs) Berberis Vulgaris Acer rubrum Corylus colurna Spiraea latifolia (common barberry) Freeman Maple (h) Norway Maple (i) Snowberry (cs) Forsythia (i)Native Trees Acer freemanii Acer platanoides Native Shrubs Symphoricarpos albus Forsythia intermediaHoney Locust Silver Maple Zelkova Staghorn Sumac var albus Alpine Current Gleditsia triacanthos Acer saccharinum Zelkova serrata Rhus typhina Silver Buffaloberry (nc) Ribes alpinumBlack Locust (i) Black Maple Amur Maple (i) Fragrant Sumac Shepherdia argentea Purple Leaf Sand Cherry Robinia pseudoacacia Acer nigrum Acer ginnala Rhus aromatica Soapberry Prunus cistenaRed Oak Northern Catalpa Japanese Lilac (i) Bush Honeysuckle (cs) Shepherdia canadensis Salt Spray/Japanese Rose (i) Quercus rubra Catalpa speciosa Syringa reticulata Diervilla lonicera Oregan Grape (nc) Rosa rugosaPin Oak Mountain Ash (cs) Smooth Wild Rose (cs) Mahonia Aquifolium Common Lilac (i) Quercus palustris Sorbus americana Rosa blanda Cockspur Hawthorn Syringa vulgarisBur Oak Evergreen Trees Pasture Rose (cs) Red Bud Crataegus crus-galli Mock Orange (i) Quercus macrocarpa Cercis canadensis Rosa carolina Downy Hawthorn Philadelphus lewisiiSwamp White Oak Native Trees (cs for Rosa virginiana) Crataegus mollis American Beautyberry Quercus bicolor White Pine Saskatoonberry Callicarpa americana Non Native Trees Amelanchier alnifolia Purple Flowering RasberryChinkapin Oak Ginkgo Pinus strobus Rubus odoratus Honeysuckle Varieties (i) Quercus muehlenbergii White Spruce Serviceberry Lonicera japonica (japanese) Ginkgo bilobaKentucky Coffee Tree Picea glauca Amelanchier laevis Lonicera tatarica (tartarian) English Oak Nannyberry Non Native Shrubs Gymnocladus dioicus Quercus robur Colorado Blue Spruce (nc) Vibernum lentago Spirea VarietiesBlack Walnut (*) London Plane Tree (h) Picea pungens Spirea japonica Juglans nigra Platanus x acerifolia Eastern White Cedar Ninebark (s) (anthony waterer) Evergreen ShrubsOhio Buckeye (cs) Thuja occidentalis Physocarpus opulifolius European Mountain Ash (i) Spirea bumalda Aesculus glabra New Jersey Tea Serbus aucaparia Ceanothus americanus (goldflame) Native ShrubsTulip Tree Common Horsechestnut (i) Non Native Trees Euonymous Varieties (i) Common Juniper Liriodendron tulipifera Austrian Pine Grey Dogwood Aesculus hippocastanum Euonymous fortunei Juniperus communisIronwood Pinus nigra Cornus racemosa Little Leaf / Greenspire Linden (sarcoxie) Creeping Juniper (c) Ostrya virginiana Scots Pine (i) Red Osier Dogwood Tilia cordata Euonymous elatus Juniperus horizontalisHackberry Pinus sylvestris Cornus stolonifera European Hornbeam (burning bush) Celtis occidentalis Norway Spruce Chokecherry Carpinus betulus Common Boxwood Non Native ShrubsAccolade Elm (h) Picea abies Prunus virginiana Callery Pear Chanticleer Buxus sempervirens Mugo Pine Ulmus ‘Accolade’ Serbian Spruce Witchhazel Pyrus calleryana ‘Chanticleer’ Barberry Varieties (i) Pinus mugoRedmond Linden (h) Picea omorika Hamamelis virginiana Amur Cork Tree Berberis thunbergii Savin Juniper Tilia americana ‘Redmond’ Siberian Larch Shrubby Cinqufoil Phellondendron amurense (japanese barberry) Juniperus sabina Larix sibirica Potentilla fruticosa
4 Commonly Planted Drought Tolerant Landscaping Species NOTATIONS (i) invasive species, not to be planted near natural ravine areas. (cs) commonly substituted species, carefully select appropriate species (h) hybrid species, genetic hybrid of native and non native species (nc) native canadian species, native to Canada, not to Southwestern Ontario (*) Black Walnut juglone toxicity, plant walnut associated species in understoryPERENNIAL FLOWERS GRASS GROUND COVERS VINESPerennial Flowers Hoary Vervain Non Native Flowers Perennial Grass Ground Covers Vines Verbena stricta Purple Coneflower/Echinacea Showy Tick -Trefoil Echinacea purpureaNative Flowers Desmodium canadense Butterflybush Native Grasses Native Groundcovers Native VinesWild Bergamot/ Bee Balm Spotted Joe-Pye Weed Indian Grass Creeping Juniper Virginia Creeper Buddleia davidii Monarda fistulosa Eupatorium maculatum Sorghastrum nutan Juniperus horizontalis Parthenocissus vitacea Autumn Joy SedumGrey Headed Coneflower Boneset Switch Grass Bearberry (cs) Wild Grape Sedum spectabile Ratibida pinnata Eupatorium perfoliatum Panicum virgatum Arctostaphylos uva-ursi Vitis riparia Daylillies (i)Narrow Leaf Coneflower Ironweed Big Bluestem Hemerocallis species Echinacea angustifolia Vernonia gigantea Andropogon gerardii Non Native Common Daisy Non Native VinesPale-Leaved Sunflower Cup Plant Little Bluestem Helianthus stumosus Chrysanthemum leucanthmum Schizachyrium scoparium Groundcovers Boston Ivy Silphium perfoliatum Shasta Daisy Periwinkle (i)Ox Eye Sunflower Hairy Panic Grass Parthenocissus tricuspidata Butterfly Milkweed Leucanthemum superbum Vinca minor Heliopsis helianthoides Panicum acuminatum Trumpet Vine Asclepias tuberosa Marguerite Daisy Euonymous (i)Showy Sunflower (h) Northern Dropseed Campsis radicans Common Milkweed Argyranthemum frutescens Euonymous fortunei Helianthus laetiflorus Asclepias syriaca Sporobolus heterolepis Red Valerian Cottoneaster (i)Woodland Sunflower Wild Columbine Tufted Hairgrass Centranthus ruber Cotoneaster damerrii Helianthus divaricatus Aquilegia canadensis Deschampia caespitosa Common Yarrow Japanese Spurge (i)Sky Blue Aster Aster oolentangiensis Blanket Flower Achillea millifolium Common Wood Sedge Carex blanda Pachysandra terminalis TURF GRASS Gaillardia aristata Common Sage Lamb EarsNew England Aster Foxglove var Huskar’s Red Salvia officinalis Stachys byzantina Drought tolerant Aster novae-angliae Non Native Grasses Penstemon digitalis Russian Sage Perrenial Alyssum lawn mixtures:Smooth Aster Feather Reed Grass Lavander Hyssop Perovskia atriplicifolia Aurinia saxatilis Creeping Red Fescue Aster laevis Calamagrostis acutiflora Agastache foeniculum Sea Holly Creeping Thyme Festuca rubraBigleaf Aster Fountain Grass Harebell Eryngium maritimum Thymus serpyllum Hard Fescue Aster macrophyllus Pennisetum setaceum Campanula rotundifolia Speedwell Ice Plant Festuca duriusculaBlack Eyed Susans Porcupine/Zebra Grass (i) Western Pearly Everlasting Veronica longifolia Delosperma species Chewings Fescue Rudbeckia hirta Miscanthus sinensis Anaphalis margaritacea Perrenial Cornflower Stonecrop Festuca rubra commutataCoreopsis/Tickseed Ribbon Grass (i) Stiff Leaved Goldenrod Centaurea montana Sedum species: Perennials Rye Coreopsis lanceolata Phalaris arundinacea Solidago rigida Dianthus Sedum album Lolium perenneCylindrical Blazing Star Blue Fescue False Indigo Dianthus barbatus Sedum rupestre Pennsylvanian Sedge Liatris cylindracea Festuca glauca Baptisia australis Lavender Hens and Chicks Carix pensylvanica (r)Dense Blazing Star Lavandula officinalis Sempervivum tectorum Liatris spicata
5 Native Southern Ontario Drought Tolerant LandscapesCarolinian Forest LandscapeThe Carolinian Forest is a life zone that extends along theeastern board of North America between the Carolinasand Southwestern Ontario, the northerly limit extendingto the Toronto area. It is characterized by a predominanceof deciduous, broad leaf trees and is rich in biodiversity;40 percent of Ontario’s rare plants are found exclusively inthe Carolinian forest. Many Carolinian species prefer well-drained, sandy, often acidic soils which in turn makes manyCarolinian species suitable to drought tolerant landscapesgiven appropriate soil conditions. Drought tolerant Carolinianspecies include:Deciduous Trees Shrubs Perennial FlowersRed Oak Shagbark Hickory (r) Red Bud Witch Hazel Showy Tick-Trefoil Quercus rubra Carya ovata Cersis canadensis Hamamelis virginiana Desmodium canadenseBlack Oak (r) Kentucky Coffee Tree Sassafras (r) Nannyberry Butterfly Milkweed Quercus velutina Gymnocladus dioicus Sassafras albidum Vibernum lentago Asclepias tuberosaPin Oak American Chestnut (r) Black Gum (r) Choke Cherry Wild Bergamot Quercus palustris Castanea dentata Nyssa sylvatica Prunus virginiana Monarda fistulosaBur Oak Northern Catalpa Cucumber Tree (r) Canada Plum (r) Ironweed Quercus macrocarpa Catalpa speciosa Magnolia acuminata Prunus nigra Vernonia giganteaChinkapin Oak Sycamore (r) Red Mulberry (r,cs) Staghorn Sumac Cup Plant Quercus muehlenbergii Platanus occidentalis Morus rubra Rhus typhina Silphium perfoliatumBlack Walnut (*) Tulip Tree (cs for Morus alba) Grey Dogwood Lance Leaf Coreopsis Juglans nigra Liriodendron tulipifera Flowering Dogwood Cornus racemosa Coreopsis lanceolata Cornus florida Pasture Rose Rosa carolina (r) rare species, difficult to obtain from nurseries, sensitive to environmental conditions
6 Native Southern Ontario Drought Tolerant LandscapesOak Savanna LandscapeA Savanna is a term applied to natural grassland areas withscattered open-grown trees. Ontario contains native OakSavannas within the Carolinian Forest of SouthwesternOntario, primarily along the sandy bluffs of the Old LakeIroquois shoreline such as High Park in Toronto. Savannas andprairies develop on sites which are subject to environmentalstresses, typically fire, drought, spring flooding, and warmerthan usual local climates. Savanna sites in the Carolinianregion are found mostly on very sandy soils which makes manysavanna species suitable for drought tolerant landscaping.Oak Savanna species planted in development landscapes willrequire appropriate soil conditions, those conditions foundnaturally within Toronto occur along the Old Lake Iroquoisshoreline, south of St. Clair Ave. Drought tolerant Savannaspecies include:Deciduous Trees Shrubs Perennial Flowers GrassesRed Oak Shagbark Hickory (r) Smooth Wild Rose Bush Honeysuckle Wild Bergamot Little Bluestem Quercus rubra Carya ovata Rosa blanda Diervilla lonicera Monarda fistulosa Schizachyrium scopariumBlack Oak (r) Bitternut Hickory (r) Serviceberry Snowberry (cs) Black Eyed Susans Big Bluestem Quercus velutina Carya cordiformis Amelanchier laevis Symphoricarpos albus Rudbeckia hirta Andropogon gerardiiPin Oak Pignut Hickory (r) Grey Dogwood Ninebark Butterfly Milkweed Indian Grass Quercus palustris Carya glabra Cornus racemosa Physocarpus opulifolius Asclepias tuberosa Sorghastrum nutansBur Oak White Pine Chokecherry Nannyberry Showy Tick-Trefoil Switch Grass Quercus macrocarpa Pinus strobus Prunus virginiana Vibernum lentago Desmodium canadense Panicum virgatumBlack Cherry Red Pine (r) New Jersey Tea (r) Woodland Sunflower Prunus serotina Pinus resinosa Ceanothus americanus Helianthus divaricatusPin Cherry Eastern Red Cedar Staghorn Sumac Wild Lupine (s) Prunus pensylvanica Juniperus virginiana Rhus typhina Monarda fistulosa (r) rare species, difficult to obtain from nurseries, sensitive to environmental condi-
7 Native Southern Ontario Drought Tolerant LandscapesTall Grass Prairie and MeadowLandscape Tall Grass Prairie is a natural community within the Carolinianlife zone of Southern Ontario which is dominated by grassesand wildflowers. It is typically found on drier, nutrient-poorsoil and depends on fire to flourish. Meadow landscapesin contrast, depend on cycles of flooding and drought tomaintain an open, treeless habitat. Due to their naturalhabitat both Tall Grass Prairie and Meadow species areexcellent drought tolerant landscaping candidates requiringmedium to full sun exposure. Drought tolerant prairie andmeadow species include:Shrubs Perennial Flowers GrassesGrey Dogwood Wild Bergamot Black Eyed Susans Little Bluestem Cornus racemosa Monarda fistulosa Rudbeckia hirta Schizachyrium scopariumSmooth Wild Rose Dense Blazing Star Wild Lupine Big Bluestem Rosa blanda Liatris spicata Lupinus perennis Andropogon gerardiiNew Jersey Tea (r) Grey Headed Coneflower Showy Tick-Trefoil Indian Grass Ceanothus americanus Ratibida pinnata Desmodium canadense Sorghastrum nutansSoapberry Butterfly Milkweed Hairy Bush Clover Switch Grass Shepherdia canadensis Asclepias tuberosa Lespedeza hirta Panicum virgatum Common Milkweed New Jersey Tea (r) Hairy Panic Grass Asclepias syriaca Ceanothus americanus Panicum acuminatum Tall Sunflower Boneset Northern dropseed Helianthus giganteus Euphatorium perfoliatum Sporobolus heterolepis Prairie Dock Sisyrinchium albidum
8 Cultural Drought Tolerant LandscapesButterfly LandscapeA butterfly landscape incorporates many Tall Grass Prairie andMeadow landscape species, except species are selected basedon their preference by butterflies for food or shelter. Manybutterflies such as the Monarch and Viceroy prefer colorfuland scented flowering plants in warm, sunny locations.Butterfly gardens are ideal landscapes for developmentslooking for low maintenance, colorful, scented, andecologically friendly gardens. Butterfly preferred droughttolerant species include:Shrubs Perennial Flowers GrassesRed Osier Dogwood Butterfly Milkweed Sky Blue Aster Ironweed Little Bluestem Cornus stolonifera Asclepias tuberosa Aster oolentangiensis Vernonia gigantea Schizachyrium scopariumGrey Dogwood Common Milkweed New England Aster Boneset Big Bluestem Cornus racemosa Asclepias syriaca Aster novae-angliae Euphatorium perfoliatum Andropogon gerardiiSmooth Wild Rose Butterfly Bush Smooth Aster Blanket Flower Hairy Panic Grass Rosa blanda Buddleia davidii Aster laevis Gaillardia aristata Panicum acuminatumNannyberry Grey Headed Coneflower Black Eyed Susan Showy Tick-Trefoil Tufted Hairgrass Vibernum lentago Ratibida pinnata Rudbeckia hirta Desmodium canadense Deschampia caespitosaCockspur Hawthorn Narrow Leaf Coneflower Wild Bergamot Field Thistle Northern dropseed Crataegus crus-galli Echinacea angustifolia Monarda fistulosa Cirsium discolor Sporobolus heterolepisDowny Hawthorn Purple Coneflower/Echinacea Stiff Leaved Goldenrod Crataegus mollis Echinacea purpurea Solidago rigida Ox Eye Sunflower Dense Blazing Star Heliopsis helianthoides Liatris spicata
9 Cultural Drought Tolerant LandscapesRock Garden LandscapeA rock garden, also known as a moraine or alpine garden, is a type oflandscape that predominantly features rocks or stones with low growingplants native to rocky or alpine environments. Originally inspired bythe collection of plants from alpine mountain regions, rock gardensare good candidates for drought tolerant landscapes due to alpinespecies abilities to withstand harsh alpine environments of extremetemperature changes with minimal amounts of soil. Rock gardensthrive in both sunny and shady locations and require good drainage andproper soil conditions, ideally situated on sloped areas with a growingmedium of sand, gravel and organic material. Drought tolerant rockgarden species include:Shrubs Perennial Flowers Perennial GroundcoversCreeping Juniper Ground Phlox Sedum Varieties: Flowering Mound Sedums: Juniperus horizontalis Phlox stolonifera S. Herbstfreude, S. SpectabileShrubby Cinquefoil Rock Cress Mat Forming Sedums: Potentilla fruticosa Arabis, Aubrieta var S. Rupestre ‘Angelina’ S. Album, S. PachycladosCotoneaster Creeping Thyme Hens and Chicks Cotoneaster horizontalis Thymus serpyllum Sempervivum tectorumSpirea Varieties Perrenial Allysum Bearberry Spirea var bumalda, japonica Aurinia saxatilis Arctostaphylos uva-ursi
10 Cultural Drought Tolerant LandscapesPre-Confederation Pioneer LandscapePioneer gardens were planted as a means of survival for NorthAmerican pioneers, consisting of many food based and medicinalplants. The gardens typically included a mixture of beneficialEuropean species and native Canadian plant species, introduced bythe local North American natives. Many pioneer landscape speciesare hardy and drought tolerant due to the pioneer’s selection oflow maintenance plant species. Drought tolerant pioneer gardenspecies include:Trees Shrubs Perennial Flowers Medicinal Perennial Flowers Food Producing PlantsBlack Walnut (*) Serviceberry Day Lillies (i) Flowering Tobacco Bur Oak, White Oak Acorns Juglans nigra Amelanchier laevis Hemerocallis var. Nicotiana alata Q. alba, Q. macrocarpaBur Oak Smooth Wild Rose Common Daisy Echinacea Black Walnut, Butternut Nuts Quercus macrocarpa Rosa blanda Crysanthemum Leucanthemum Echinacea purpurea J. nigra, J. cinerea Downy Hawthorn Cosmos St John’s Wort Jerusalem Artichoke (i) Crataegus mollis Cosmos bipinnatus Hypericum perforatum Helianthus tuberosus Common Lilac (i) Hollyhocks Lavender Scarlet Runner Bean Syringa vulgaris Alcea rosea Lavandula officinalis Phaseolus coccineus Blackberry Phlox Common Sage Serviceberry Rubus allegheniensis Phlox paniculata Salvia officinalis Amelanchier laevis Red Currant Black Eyed Susans Cammomile Blackberry Ribes rubrum Rudbeckia hirta Chamaemelum nobile Rubus allegheniensis Chokecherry Smooth Wild Rose Prunus virginiana Rosa blanda
10 Cultural Drought Tolerant LandscapesHedgerow LandscapeA hedgerow is a line of closely planted shrubs and trees designedto mark a boundary, form of barrier for privacy, serve as awindbreak and muffle sound. Natural hedgerows result from winddispersed seeds and the droppings from berry and seed eatingbirds and animals. Resultant hedgerows grow thick with vinesand wildflowers providing all the ingredients animals require forsurvival; food, shelter and nesting sites. Being opportunistic andhardy by nature, many hedgerow species are good candidates for adrought tolerant landscape. In addition hedgerow species functionwell in a landscape as a windbreak, privacy screen, and provideseasonal interest with a variety of flowering and fruit bearingspecies. Drought tolerant hedgerow species include:Trees Shrubs Perennial Flowers VinesCockspur Hawthorn Serviceberry Nannyberry (cs) Black Eyed Susan Virginia Creeper Crataegus crus-galli Amelanchier laevis Viburnum lentago Rudbeckia hirta Parthenocissus vitaceaDowny Hawthorn Chokecherry Canada Plum Bigleaf Aster Wild Grape Crataegus mollis Prunus virginiana Prunus nigra Eurybia macrophylla Vitis ripariaPin Cherry Red Osier Dogwood Witch Hazel Prunus pensylvanica Cornus stolonifera Hamamelis virginianaEastern White Cedar Smooth Wild Rose Purple Flowering Rasberry Thuja occidentalis Rosa blanda Rubus odoratus Staghorn Sumac Rhus typhina Common Hobblebush (cs) Viburnum lantanoides
11 Invasive SpeciesInvasive SpeciesMany non native drought tolerant species are both extremelyadaptive and prolific that they become invasive and shouldnever be planted near ravine or naturalizedareas. Once established in naturalized areas, these speciesout-compete native plant species, resulting in a monocultureof invasive species with low ecological value. Common droughttolerant invasive species to avoid planting near ravines andnaturalized areas include:Trees Shrubs Perennial Flowers Groundcovers GrassesNorway Maple Euonymous Varieties Forsythia St John’s Wort Periwinkle Ribbon Grass Acer platanoides Euonymous fortunei Forsythia intermedia Hypericum perforatum Vinca minor Phalaris arundinaceaBlack Locust (sarcoxie) Common Privet Day Lillies Oriental Bittersweet Porupine/Silver Grass Robinia pseudoacacia Euonymous elatus Ligustrum vulgare Hemerocallis var. Celastrus orbiculatus Miscanthus sinensisCommon Horsechestnut (burning bush) Cottoneaster Borage Japanese Honeysuckle Rough Manna Grass Aesculus hippocastanum Common Lilac Cotoneaster damerrii Borago officinalis Loniceria japonica Glyceria maximaEuropean Mountain Ash Syringa vulgaris Mock Orange Tansy Japanese Spurge Serbus aucaparia Japanese/Multiflora Rose Philadelphus lewisii Tanacetum vulgare Pachysandra terminalisAmur Maple Rosa rugosa False Spirea Acer ginnala Siberian Peashrub Sorbaria sorbifoliaScot’s Pine Caragana arborescens Western Snowberry Pinus sylvestris Common/Japanese Barberry Symphoricarpus albus var.Russian Olive B.vulgaris, B. thunbergii Elaeagnus angustifolia
12 References Baldwin, B and Tanino, K. 1996. Physiology of Drought in Stressed Plants. Gardenline. http://gardenline.usask.ca/misc/xeris.html Benson, P. n.d. How To Create a Pioneer Garden. EHow. http://www.ehow.com/how_4432104_create-pioneer-garden.html Borgmann, K.L., and Rodewald, A.D. 2002. Butterfly Gardens. Ohio State University. http://ohioline.osu.edu/w-fact/0012.html Drought Tolerant Perrenials. Toronto Master Gardener Factsheet. Toronto Botanical Garden. http://www.torontobotanicalgarden.ca/mastergardener/DroughtTolerantPerennials.shtml Drought Tolerant Shrubs. NC State University. http://www.ces.ncsu.edu/depts/hort/consumer/quickref/shrubs/shrubs-drought.html Drought Tolerant Trees. NC State University. http://www.ces.ncsu.edu/depts/hort/consumer/quickref/trees/droughttolerant.html Fyon, A. 1999. Andy’s Northern Ontario Wildflowers, Flowering Shrubs. http://www.ontariowildflower.com/shrub.htm Ground Covering Plants. City of Ottawa. http://www.ottawa.ca/residents/healthy_lawns/gardens/ground_en.html Hamilton Naturalist Club. Carolinean Forest Plants. Hamilton Nature. http://www.hamiltonnature.org/habitats/forest/forest_plants.htm Hanrahan, C. 2007. Creating a Hedgerow for Wildlife. Fletcher Wildlife Garden. http://www.ofnc.ca/fletcher/howto/hthedge_e.php Invasive Plant Lists. Royal Botanical Gardens. http://www.rbg.ca/cbcn/en/projects/invasives/i_list.html Kinsley, C. 2002. Ontario Native Plants Catalogue. Plants for Dry, Sunny, Semi-shade and Shade Conditions. Kershaw, L. 2001. Trees of Ontario. Lone Pine Publishing.
13 References Muma, W. Ontario Trees and Shrubs. http://ontariotrees.com/ Natural Habitat Communities, Prairie and Meadow Habitat. Evergreen. http://www.evergreen.ca/docs/res/Design-Ideas-5-Natural-Habitat-Communities.pdf Pioneer Garden History. Burlington Area Garden Club. http://www.burlingtonareagardenclub.org/pioneer.php Rock Garden Plantings. Landscape Ontario. http://www.landscapeontario.com/c?c=1256 Soper, J.H. 1990. Shrubs of Ontario. Royal Ontario Museum Publishing. The Truth about TallGrass. Carolinean Canada. http://www.carolinian.org/SpeciesHabitats_TGPandSavanna.htm Toront Green Standard. Green Standard and Checklist. Water Efficiency http://www.toronto.ca/planning/environment/greendevelopment.htm Urban Forestry Facts #2, How to Select and Buy Native Plants. City of Toronto. http://www.toronto.ca/trees/pdfs/Fact_2_How_to_Select_and_Buy_Native_Plants.pdf Water Efficient and Native Plant Lists.Toronto Water. City of Toronto. http://www.toronto.ca/watereff/landscaping/plant_lists.htm What is a Carolinean Forest. Carolinean Canada. http://www.carolinian.org/SpeciesHabitats_Forests.htm