A Guide for Southern Ontario
Beautiful Non-Invasive Plants for your Garden
Edition 3, 2020 Foreword Table of Contents Foreword from Horticulture Outreach Collaborative...... 1 Welcome to the third edition of Grow Me Instead. Whether you are a Impacts of Invasive Plants in Ontario...... 3 novice or a seasoned pro, a hobbyist or a professional, a designer or Native Plants...... 4 a builder, this guide is for you. Gardening Best Management Practices...... 5 Back in 2009, a group of ecologists and horticulturalists gathered Ontario Invasive Species Act...... 6 to discuss the issue of invasive garden plants. They formed the Groundcovers, Wildflowers and Grasses Horticulture Outreach Collaborative (HOC), which soon became a Periwinkle, Lily-of-the-Valley...... 7 committee of the Ontario Invasive Plant Council (OIPC). Although HOC has worked on numerous projects, none has generated as much Goutweed, Yellow Archangel...... 9 discussion and received as much praise as this little guide. And so it Wintercreeper...... 11 is with great pleasure that we introduce this third edition of Grow English Ivy, Bugleweed...... 13 Me Instead (GMI) for Southern Ontario. Creeping Jenny...... 15 More than 70,000 people have picked-up earlier editions of GMI Daylily...... 17 and countless more have referred to or downloaded them online. With updated plant profiles and photos as well as more information Miscanthus...... 19 on plant availability and wildlife connections, we believe this third Trees and Shrubs edition is the best yet. Norway Maple, Amur Maple...... 23 The most successful projects are collaborative in nature, and GMI Winged Euonymus...... 25 is no exception to the rule. We thank past and present OIPC staff Russian Olive, Autumn Olive...... 27 members and HOC committee members as well as everyone who has picked-up a guide over the last eight years and let us know what Japanese Barberry they thought, good and bad. Tartarian, Amur, Morrow, Bells, European Fly Honeysuckles...... 29 Multiflora Rose...... 31 Most especially, we would like to thank the Ontario Federation of Anglers and Hunters’ Invading Species Awareness Program, Toronto Sea Buckthorn...... 33 Botanical Garden, and the Invasive Species Centre for driving this Vines third edition home. Japanese Honeysuckle Vine...... 37 Yours in conservation, Oriental Bittersweet...... 39
Colin Cassin and Colleen Cirillo Aquatics Yellow Iris...... 41 HOC committee co-chairs Flowering Rush...... 43 Water Lettuce, Water Soldier...... 47 European Frog-bit, Yellow Floating Heart...... 49 Fanwort, Hydrilla...... 51 Watch List...... 55 Acknowledgements...... 57
Brenda Van Ryswyk
1 Ontario Invasive Plant Council ontarioinvasiveplants.ca 2 Grow Me Instead • Reduced forage quality and quantity on rangelands • Increased competition for light, nutrients and water on tree Gardening is a popular activity in southern Ontario and around the seedling farms world. When practiced in a thoughtful manner, it is part of society’s wise response to climate change and biodiversity loss – two of our • Additional tourism nuisances such as punctured tires, trail greatest global challenges. Invasive plants contribute greatly to the obstruction and degraded vistas later and cost governments and land owners tremendously. • Water quality and quantity degradation due to increased erosion This practical and easy-to-use guide is part of that thoughtful and sedimentation approach. It informs gardeners about the invasive tendencies of common garden plants and suggests appropriate non-invasive Invasive plant removal is extremely difficult, if not impossible, alternatives. In addition, it provides tips for ecologically-sound especially when well-established over large areas. Prevention of gardening and a list of related resources. new invasions is of paramount importance. Invasive plants Native plants A non-native plant is a plant that is introduced into an area for A native plant has existed in an area for millennia, and has evolved horticultural or agricultural reasons, or by accident. Many non- in the presence of native soils and climate, and in tandem with native plants in southern Ontario are beneficial to society and other native species of plants, animals, fungi and bacteria. This non-threatening to native biodiversity, others are benign. Only a vegetation may also be referred to as indigenous. Native plants few are invasive. exist as part of naturally-forming communities and have important ecological roles to play. The native plants of southern Ontario are An invasive plant is a non-native plant whose introduction diverse, and beautiful. negatively impacts native biodiversity, the economy and/or society, including human health. Second to habitat loss, invasive species While it is true that non-native plants can provide shelter, nesting have been identified by the International Union for Conservation of opportunities and some food options for wildlife, native plants Nature as the most significant threat to biodiversity. support a greater diversity and number of wildlife, including the bees, butterflies and birds we love to see in our gardens. The Invasive plants have far-reaching and long-lasting impacts. They significant difference is the ability of native plants to support reduce populations of native plants and the insects that depend native insects. on those plants, permanently altering communities and ecosystem functions, and costing economies millions of dollars each year. It’s a chemistry thing. Our plant-eating insects have evolved with native plants so that they can combat the defenses of some of Invasive plants impact a great number and diversity of citizens, them and avoid those for which they cannot. Many insects – at regions and industries across southern Ontario, as detailed in the least in the larva stage – are specialized. This means that they feed list below: on one specific plant or a small number of plants only. The monarch is the perfect specialization example as it only consumes milkweed • Increased monitoring and maintenance costs (labour, plant in its larva form (caterpillar). replacement and chemical use) for public parks and gardens, land trusts and private land managers Non-native plants are brand new to native insects and not palatable. Our insects have not evolved with them and cannot combat their chemical defenses to consume them and derive nourishment. So when our gardens and parks are filled with non- native plants, we have fewer insects and fewer birds that rely on them for food. So add some native plants to your garden to best support our native wildlife at all stages of life, and transform your garden into a vibrant, dynamic space! A list of native plant nurseries can be found in the Additional Resources section at the end of this guide.
Jessica Rose Powell 3 Ontario Invasive Plant Council ontarioinvasiveplants.ca 4 Caring for your garden and nearby Ontario’s Invasive Species Act natural areas The Invasive Species Act (ISA) came into force on November 3rd, 2016. The goal of the Invasive Species Act is to support the prevention, early • Learn what plants are in your garden. The website iNaturalist.org is a detection, response to and eradication of invasive species in Ontario. great free source of experts whom readily provide identification support. Preventing invasive species from arriving and becoming established in • If an invasive is discovered, remove to prevent spread using Ontario is critical in the fight against this growing threat. techniques such as digging, flower head removal before seed set, Some key elements of the Invasive Species Act include: or hiring a professional to apply herbicides. • Giving Ontario the tools to regulate invasive species as either • When removing invasive plants, do not place them in your Prohibited or Restricted and banning activities such as buying, backyard composter as the temperatures will not get high enough selling, possessing and transporting certain invasive species; to kill the seeds or plant parts. Some compost programs at waste • Enabling response actions to address urgent threats, and; management facilities may reach a heat high enough to kill viable • Helping to promote compliance through modernized inspection and plant parts (ie. Seeds and roots). It is always good to call ahead enforcement measures. first and inquire. Otherwise, a best practice is to place the material in black garbage bags and dispose of them with your household Ontario has regulated several invasive species including plants under garbage. Some particularly hardy invasive plants may require the ISA. The following is a list of plant species currently regulated under prolonged solar heating within the garbage bags to ensure all the ISA in Ontario. plant material is thoroughly killed.
• Do not throw your garden or yard waste over your fence into Prohibited Invasive Species natural areas. This is a proven way that invasive plants spread into It is illegal to import, possess, deposit, release, transport, breed/grow, natural areas. buy, sell, lease or trade these prohibited invasive species in Ontario: • Do not dump any aquatic plants or animals into natural waterways • Brazilian Elodea (also known as Brazilian Waterweed) (Egeria densa) or ponds. • European Water Chestnut (Trapa natans) • Do not remove vegetation from natural areas; they may be rare • Hydrilla (Hydrilla verticillata) native plants or even invasive plants. • Parrot Feather (Myriophyllum aquaticum) • Purchase non-invasive or native plants from reputable suppliers. • Water Soldier (Stratiotes aloides) A list of nurseries specializing in native plants can be found in the Additional Resources section at the end of this guide. Restricted Invasive Species • Talk to growers and express the demand for native, non-invasive It is illegal to import, deposit, release, breed/grow, buy, sell, lease or alternatives. trade these four restricted invasive species: • Report invasive species sightings to the Invading Species • Dog-strangling Vine (Vincetoxicum rossicum) (syn. Cynanchum rossicum) Awareness Program’s hotline 1-800-563-7711 or Early • Black Dog-strangling Vine (Vincetoxicum louiseae) Detection and Distribution Mapping System for Ontario (syn. Cynanchum louiseae) (eddmaps.org/ontario). • Japanese Knotweed (Fallopia japonica var. japonica) (syn. Reynoutria japonica var. japonica) Freyja Whitten • Phragmites (Phragmites australis subsp. australis)
5 Ontario Invasive Plant Council ontarioinvasiveplants.ca 6 Groundcovers, Wildflowers and Grasses
PERIWINKLE is native to INVASIVE Garden use: groundcover for ALTERNATIVE Europe, but can now be shady woodland garden found in gardens throughout Growing conditions: sun to North America. Its popularity partial shade; dry to moderate; is based on its ease of care, sand or clay dense growth, and its ability to grow in dry shade, a difficult Size and shape: 30 – 60 cm UNWANTED gardening situation. tall; clump-forming
Periwinkle grows to a height of R. Old Flower and fruit: showy pink City of Toronto 10 – 15 cm and is characterized or magenta blooms in late- by glossy evergreen foliage and Periwinkle spring and early-summer Wild Geranium (Vinca minor) (Geranium maculatum) long-lasting blue-violet flowers. Leaves: loose mounds of It has few pests or diseases deeply-lobed leaves outside its native range, which contributes to its persistence. It spreads via its shallow root system and can survive in a range of Additional info: nectar source for hummingbirds; often forms colonies soil conditions.
LILY-OF-THE-VALLEY is an INVASIVE Garden use: groundcover for ALTERNATIVE herbaceous perennial native shady woodland garden to Eurasia which has escaped Growing conditions: prefers cultivation in North America. partial shade and dry to moist This highly poisonous plant and well-drained soils; adaptable spreads rapidly via rhizomes, and tolerates a range of Size and shape: 25 – 50 cm tall UNWANTED growing conditions, forming Flower and fruit: terminal dense colonies in the landscape. F. WhittenS.Smith clusters of white star-shaped K. Powell Lily-of-the-valley prefers shaded flowers in spring followed by areas with filtered light and Lily-of-the-valley distinctive green-and-black Starry Solomon’s Seal is found in urban parks and (Convallaria majalis) striped berries, which turn deep (Maianthemum stellatum) ravines, and more remote red when ripe settings of natural woodlands Leaves: alternating/zigzag-like arrangement of lance-shaped of southern and central Ontario. leaves clasped on stem In these habitats, it out- Additional info: spreads by rhizomes and forms colonies competes many native woodland groundcovers.
F. Whitten
7 Ontario Invasive Plant Council ontarioinvasiveplants.ca 8 Groundcovers, Wildflowers and Grasses
GOUTWEED is native to Eurasia INVASIVE Garden use: groundcover for ALTERNATIVE but can now be found in gardens shade/partial light throughout North America. Growing conditions: tolerant Also referred to as Bishop’s weed of wide light range, and dry to and snow on the mountain, moist soils this perennial groundcover Size and shape: 50 – 100 cm; tolerates a wide range of soil UNWANTED forms large carpets conditions. It is highly shade- tolerant and competitive once R. Krick Flower and fruit: delicate K. Powell established, reproducing by seed flowers in white, violet or and spreading by underground Goutweed lavender; many flowers per plant Large-leaved Aster (Aegopodium podagraria) (Eurybia macrophylla) stems called rhizomes. It is most Leaves: heart-shaped large basal commonly found around shrubs leaves (5 – 15 cm), with oval/ in old gardens. lance-shaped gradually becoming Plants grow about 30 cm high smaller as they ascend the stem with green leaves that are divided Additional info: this aster is into three leaflets. Some cultivars widespread in Ontario woodlands have variegated leaflets that are and edge habitats, and one of the green near the centre but whitish first asters to bloom around their margins. Umbrella- L. J. Mehrhoff K. Powell like white flowers appear in mid-summer.
YELLOW ARCHANGEL is an INVASIVE Garden use: groundcover; ALTERNATIVE invasive perennial ground cover woodland habitat garden from the native to Europe. Growing conditions: tolerate This invasive groundcover is a range of light conditions a member of the mint family but prefer partial shade; dry and often escapes cultivation to moist soil (adapted to dry establishing in a range of UNWANTED conditions) conditions, from full shade to full sun, and from moist to Size and shape: 50 – 80 cm tall; A. Oommen K. Powell dry soils. It has been known tends to grow in groups/clumps to survive extreme conditions Yellow Archangel Flower and fruit: golden Zigzag Goldenrod such as periods of drought, (Lamiastrum galeobdolon) yellow flowers bloom in late (Solidago flexicaulis) and in soils with high pH, such summer and early fall in as those found within cedar and hemlock dominant woodlands. pinnacles spread along the top of the stem Its ability to adapt to a broad spectrum of habitats and conditions make it very successful at out-competing native flora. Leaves: coarsely toothed, point, oval-heart shaped leaves arranged along zigzag shaped stems Yellow archangel reproduces via seed, root fragments, and through stolons, which produce roots and shoots at the leaf base near Additional info: flowers very nice addition for autumn colour the ground, enabling it to form extensive ground cover from an individual plant.
9 Ontario Invasive Plant Council ontarioinvasiveplants.ca 10 Groundcovers, Wildflowers and Grasses
WINTERCREEPER is a woody, INVASIVE Garden use: groundcover for ALTERNATIVE shade-tolerant evergreen shady woodland or rock garden trailing shrub or climbing vine Growing conditions: partial native to Asia. Its attractive to full shade; average to moist, foliage and versatility for hedge, humus rich loam soils foundation, and erosion control plantings have made it a Size and shape: 13 – 25 cm tall UNWANTED desirable ornamental. Flower and fruit: small white Wintercreeper grows in urban James H. Miller star-like flowers on spikes in S. Coulbert and disturbed areas as well as a spring and early-summer variety of forest types. Seeds are Wintercreeper Foamflower (Euonymus fortunei) Leaves: maple-like leaves (Tiarella cordifolia) dispersed by birds into natural turn red in fall and remain areas where they form dense throughout winter and aggressive groundcovers. Additional info: spreads by Characterized by finely toothed, egg-shaped evergreen foliage and runners inconspicuous greenish-yellow flowers, wintercreeper can grow 1 m tall as a shrub and up to 22 m as a vine. With few pests and pathogens affecting its growth in Ontario, this ornamental is a S. Coulbert persistent invader of native groundcover habitat.
Garden use: groundcover in shade ALTERNATIVE Garden use: groundcover for ALTERNATIVE shady location Growing conditions: partial shade; rich and moist; well- Growing conditions: partial drained soil to full shade; moist conditions Size and shape: low, trailing Size and shape: 25 – 50 cm; deciduous shrub up to 45 cm tall low growing Flower and fruit: red berries Flower and fruit: white to
in the fall S. James light purple tubular flowers with R. Gray protruding stamens Leaves: dense foliage turns Running Euonymus Virginia Waterleaf scarlet in the fall (Euonymus obovatus) Leaves: broadly triangular (Hydrophyllum virginianum) leaves, lobed almost to the Additional info: native to midrib; some specimens with eastern North America a distinguishable spotted (or water droplet-like) appearance on the leaves Additional info: attracts native bees and other pollinators R. Gray
11 Ontario Invasive Plant Council ontarioinvasiveplants.ca 12 Groundcovers, Wildflowers and Grasses
ENGLISH IVY is native to INVASIVE Garden use: groundcover for ALTERNATIVE Europe, western Asia and sunny gardens northern Africa. It has been Growing conditions: sun; developed into hundreds of sand, loam or clay; dry to varieties and can now be average soil found in gardens throughout North America. Size and shape: low-growing UNWANTED and spreading; 15 cm tall Although technically a vine, this evergreen perennial F&K Starr Flower and fruit: small white R. Gray is commonly used as a flowers in late-spring; small groundcover in dense shade. English Ivy edible red berries early-summer Wild Strawberry (Hedera helix) (Fragaria virginiana) Whether in shade or sun, Leaves: three-lobed and toothed English ivy will persist and spread vegetatively through its long vines that root at the nodes in Additional info: spreads by almost any soil type. It is easily identified by its dark green three- runners and forms colonies lobed leaves placed alternately on its flexible woody vine. Despite its pervasiveness in gardens and nearby natural areas, not a single North American animal uses English ivy for food. Indeed, this is one of the causes of its invasive nature, the other being its considerable adaptability. R. Gray
BUGLEWEED is a low- INVASIVE Garden use: groundcover for ALTERNATIVE growing, perennial groundcover shady location native to Europe, Africa and Growing conditions: part Asia. Its pleasant blue blossoms sun to shade; average to moist, and ability to suppress weeds humus-rich soil and cover shaded areas made it popular for filling in lawns, Size and shape: 15 – 20 cm UNWANTED stabilizing slopes and covering tall; clump-forming areas under trees and shrubs. K. Peterson Flower and fruit: single F. Whitten Bugleweed spreads through maroon flower under leaves in stolons quickly taking over Bugleweed late-spring Wild Ginger (Ajuga reptans) (Asarum canadense) native groundcover and gardens. Leaves: soft green heart-shaped It is characterized by glossy, dark green-purple egg-shaped leaves with the narrow end towards the Additional info: spreads slowly by roots to form attractive base and upright spikes of dense blueish-purple flowers. groundcover; drought-tolerant once established; deer-resistant; roots have a sweet ginger smell
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CREEPING JENNY is an INVASIVE Garden use: groundcover; ALTERNATIVE herbaceous perennial plant native plant garden; roadside, native to Eurasia. It is favored prairie and meadow gardens by gardeners for its low Growing conditions: stature and ability to grow in adaptable to a variety of light wet areas in a wide range of and soil conditions, but does light conditions. UNWANTED best in partial to full sun and Creeping Jenny grows 20 – moist soils 60 cm long and 5 – 10 cm L. J. Mehrhoff K. Powell Size and shape: 30 – 60 cm tall high. The toothless, spade shaped leaves can vary from Creeping Jenny Flower and fruit: showy Canada Anemone green to yellow in colour (Lysimachia nummularia) white flowers emerge from late (Anemone canadensis) based on sunlight exposure. May through the summer Flowers are yellow with dark red spots, though they rarely form. Leaves: deeply lobed and It spreads vegetatively, creating a dense leafy mat excluding toothed leaves other native herbaceous vegetation from establishing. Additional info: great for pollinators with long blooming period B. van Ryswyk
Garden use: specimen ALTERNATIVE Garden use: groundcover for ALTERNATIVE planting, showy-addition shade; woodland garden Growing conditions: partial Growing conditions: part sun/shade to full shade; moist, sun to deciduous shade (needs rich, organic soils spring sun); average to most soil Size and shape: 10 – 15 cm tall; Size and shape: up to 40 cm solitary plants; will colonize space tall with one or two leaves over time in optimal conditions F. Whitten Flower and fruit: a single S. Coulber Flower and fruit: bright white white flower under leaves in with 8 to 16 white petals, with Bloodroot spring Mayapple green/yellow center (Sanguinaria canadensis) (Podophyllum peltatum) Leaves: large, umbrella-like, Leaves: blue-green leaves deeply lobed leaves unravel in are oval with deep lobes and early spring smooth texture Additional info: one of the Additional info: ephemeral first wildflowers to emerge early spring blooms that benefit in spring; flowers attract pollinators and ants will die back K. Powell bumblebees though the primary S. Coulbar allowing for increased leaf growth mechanism of pollination is still poorly understood; in part of its range, mayapple relies on box turtles for seed dispersal
15 Ontario Invasive Plant Council ontarioinvasiveplants.ca 16 Groundcovers, Wildflowers and Grasses
DAYLILY is a perennial flowering INVASIVE Garden use: native plant garden; ALTERNATIVE plant introduced from Asia in the prairie and meadow gardens early 19th century. This popular Growing conditions: partial garden plant was admired due shade to full sun; moist soils (will to its beauty, hardiness, ability tolerate a range of conditions) to spread and showy blooms. It is commonly found having Size and shape: 50 – 100 cm UNWANTED escaped cultivation in urban tall; can produce dense stands environments, along roadsides, with cultivation F. Whitten S. Coulber and encroaching into open Flower and fruit: several meadows, woodland edges, and Daylily flowers from one flower stalk; Michigan Lily riparian (shoreline) areas. (Hemerocallis fulva) 6 petal-like deep red-orange (Lilium michiganense) Daylilies are tolerant of a tepals, spotted in brown, curve variety of conditions, from full sun to partial shade, in dry to moist backwards deeply environments. These plants spread via seed and a network of Leaves: blade-like and tapered (15 cm, becoming smaller as they tuberous roots, and can reproduce and proliferate from a small ascend the stem); whorled around the round stem in groups of 5 to 9 fragment left behind during removal. Additional info: great attractant for swallowtail butterflies and ruby-throated hummingbirds
Garden use: groundcover; ALTERNATIVE Garden use: mass planting; ALTERNATIVE native plant garden; roadside, tall groundcover; container; prairie and meadow gardens prairie and meadow gardens Growing conditions: full Growing conditions: full sun sun; average to dry soil; to partial shade; well-drained/ drought tolerant loamy, sandy or clay soil; drought tolerant Size and shape: 90 – 120 cm tall; usually produces single stout Size and shape: rosette of stems that have coarse white S. Coulber leaves the first year and flowers F. Whitten hairs may produce multi-stemmed Pale Purple Coneflower in the second year; forms bushy, Black-eyed Susan clumps in gardens (Echinacea pallida) upright clumps that can reach (Rudbeckia hirta) 1m in height Flower and fruit: flowers can be different shades of purple or white depending on cultivar; single Flower and fruit: flowers bloom atop single stems; 8 to 20 golden flowers are produced on top of the stem; prominent centre cone orange petals with brown centres; blooms from July to October surrounded by long, slender drooping florets; blooms in early summer Leaves: leaves are covered with bristly hairs; oval in shape and Leaves: most leaves occur at the plant base, some may alternate scattered along the lower portion of the stem; lower surfaces of the leaves are Additional info: attracts birds and butterflies covered with fine white hairs; leaves are sword-like, up to 25 cm long Additional info: attracts butterflies and birds
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Miscanthus grasses are native INVASIVE Garden use: ornamental grass ALTERNATIVE to Africa and Asia, but many in border plantings; intermixed species are used in gardens in with wildflowers in prairie and temperate regions around the meadow gardens as well as world. Some common species rooftop gardens include Chinese silver grass, Growing conditions: full sun to zebra grass, amur silver grass, UNWANTED partial shade; well-drained sand among others. or loam Miscanthus is a perennial plant F. Whitten D. Laxton Size and shape: 1 – 2.5 m tall, that grows 2 m or more in clumping grass height and forms dense clumps. Miscanthus Big Bluestem (Miscanthus sinensis and M. sacchariflorus) Flower and fruit: blue-red (Andropogon gerardii) Flower heads change in colour “turkey’s foot” flowers in summer from red to pink, before maturing to a silver colour. It spreads by rhizomes and seed. Leaves: elegant blades turn bronze in the fall Additional info: extremely drought-tolerant and useful for erosion control; attracts birds R. Gray and butterflies
Garden use: mid-sized ALTERNATIVE Garden use: mid-sized ALTERNATIVE ornamental grass important to ornamental grass with prairie ecosystems conspicuous flower Growing conditions: full sun; Growing conditions: partial adapted to soils ranging from sun to partial shade; slightly dry sandy to clay-loam to moist, loamy soils Size and shape: 0.5 – 1 m tall, Size and shape: 1 – 2 m clumping bunchgrass D. Laxton Flower and fruit: together the R. Gray Flower and fruit: shining, green-brown, bristly spikelets white seed tufts mature in fall Little Bluestem resemble a bottlebrush Bottlebrush Grass (Schizachyrium scoparium) (Elymus hystrix) Leaves: slender blue-green Leaves: leaves are alternate, leaves in spring become vibrant grayish-green to dark green; up red-tan in fall to 30 cm long and 1.5 cm wide Additional info: vibrant Additional info: this grass can colour remains into early winter; be found in a range of habitats seeds are valued food source to including deciduous woodlands, small birds throughout winter R. Gray small meadows and partially R. Gray shaded riverbanks
19 Ontario Invasive Plant Council ontarioinvasiveplants.ca 20 Groundcovers, Wildflowers and Grasses
Garden use: ornamental grass; ALTERNATIVE Garden use: ornamental grass ALTERNATIVE dry garden in border plantings; intermixed with wildflowers in prairie and Growing conditions: full sun; meadow gardens as well as sand to clay; dry to medium soils rooftop gardens Size and shape: 1 – 2 m tall; Growing conditions: full sun densely clumping to partial shade; dry to moist Flower and fruit: loosely sand, loam and clay clustered seed head S. Brinker Size and shape: 1 – 2.5 m tall B. van Ryswyk Leaves: coarse blue-green leaves Switchgrass Flower and fruit: rich gold- Indian Grass Additional info: easy to grow, (Panicum virgatum) purple sprays of flowers and (Sorghastrum nutans) slow-spreading and long-lived; seeds in the fall consumed by wildlife and livestock Leaves: long, flat and narrow blades are dull to dark green Additional info: drought and compaction-tolerant; consumed by wildlife and livestock
Garden use: low growing, ALTERNATIVE Garden use: low growing, ALTERNATIVE clumping, grass-like perennial clumping, grass-like perennial suitable as a groundcover or suitable as a groundcover rain garden addition Growing conditions: part Growing conditions: part share to full shade; thrives in shade to full shade; dry to consistent, mid-moisture soils, but moist soils can tolerate drier or rocky soils Size and shape: 15 – 30 cm Size and shape: 15 – 30 cm tall; clumping T. Quin tall; clumping S. Brinker Flower and fruit: dark to Pennsylvania Sedge Flower and fruit: Ivory Sedge purple-brown flowering spikes (Carex pensylvanica) inconspicuous flowers; small, (Carex eburnea) blooming in late spring dark fruiting bodies forming later in summer Leaves: pale green leaves turn to sandy-tan in fall; narrow leaves up to 30 cm in length Leaves: soft, thread-like, green leaves from a spherical clump Additional info: turfgrass substitute under suitable conditions Additional info: great low-maintenance alternative for rock gardens requiring little to no regular mowing; can be difficult to grow from seed or areas with thin soils; tolerates deer grazing and heavy shade
21 Ontario Invasive Plant Council ontarioinvasiveplants.ca 22 Trees and Shrubs
INVASIVE NORWAY MAPLE is prized for INVASIVE Garden use: shade tree; ALTERNATIVE its dense crown and ability to specimen planting tolerate difficult urban conditions. Growing conditions: full sun Some cultivars have columnar to partial shade; moist soils crowns; others like Crimson King for silver and Freeman maples; have deep red leaves. deep, rich soils for sugar maple The prolific seed production of UNWANTED Size and shape: 30 – 35 m tall; most cultivars, coupled with upright to rounded crown the species’ ability to grow in R. Krick S. James Flower and fruit: small, dense shade, make Norway Norway Maple yellow to red flowers emerge Sugar, Silver maple especially invasive and (Acer platanoides) before leaf-out; paired, winged and Freeman Maples threatening to natural habitats. maple “keys” developing in (Acer saccharum, A. saccharinum and A. x freemanii) Many urban ravines and parks exhibit nearly pure stands of this species. spring (silver and Freeman), and The dense shade in these stands prevents sunlight from reaching the spring to fall (sugar maples) ground, making it difficult for groundcovers and shrubs to grow. Wildlife Leaves: medium to light green deeply lobed leaves; fall colours habitat is compromised and bare soil becomes susceptible to erosion. from brilliant yellows to reds To easily distinguish between Norway maple and native maples, break- Additional info: native maple trees are well-adapted to the climate off a leaf stem and look for the tell-tale milky sap of the Norway maple. usually requiring less maintenance than non-native options, while providing benefits to wildlife; be sure to understand species-suitability for the growing site
AMUR MAPLE has escaped INVASIVE Garden use: rounded form used ALTERNATIVE cultivation into many natural in specimen or roadside plantings areas across southern Ontario. Growing conditions: prefers Although some sterile varieties full sun but will tolerate partial may be available, a track record shade; prefers well-drained soils of invasiveness has resulted but will tolerate average to dry in neighbouring jurisdictions UNWANTED locations; displays some salt regulating the sale of the and heat tolerance species to mitigate its impact P. Wray S. James on the environment. Size and shape: 6 – 10 m One of the reasons for concern Amur Maple Flower and fruit: both flowers Ruby Lace Honeylocust with this species is its ability (Acer ginnala) and fruit of this tree offer limited (Gleditsia triacanthos var. inermis) to produce remarkably high aesthetic/wildlife benefits volumes of viable seed. Mature Leaves: small leaflets in an individuals can produce thousands of seeds annually that can be attractive purple/maroon/red colour controlled in manicured environments though regular mowing. Unfortunately, many seeds find their way to natural areas where Additional info: native range their growth is not restricted, creating dense stands of invasive expanding as far north as trees/shrubs. Pennsylvania; offers acclaimed foliage colour T. Davis Snydor
23 Ontario Invasive Plant Council ontarioinvasiveplants.ca 24 Trees and Shrubs
First introduced in North INVASIVE Garden use: specimen ALTERNATIVE America in the mid to late planting; edible ornamental; 1800’s, WINGED EUONYMUS screen; naturalized area quickly gained popularity for its Growing conditions: full sun attractive growth form, unique to part shade; moist to semi-dry winged stems and vibrant fall soils; tolerant of a wide range foliage. The vibrant berries of UNWANTED of soil conditions this invasive shrub are produced in high volume and can be Size and shape: 5 – 8 m tall P. Wray S. James consumed and deposited away with round, open crown from maintained plantings, Winged Euonymus Flower and fruit: white flower Downy, Smooth and Canada enabling this shrub to naturalize (Euonymus alatus) Serviceberry clusters at branch tips in spring; (Amelanchier arborea, A. laevis outside intended areas. edible fruit ripen in early summer and A. canadensis) Although it does not grow at the same rate as some of its invasive Leaves: emerging leaves shrub counterparts, this species maintains the ability to outcompete purplish-bronze on A. laevis many native shrubs. It also typically seen as an inferior source of only; both species rich green food and habitat compared with similar sized native shrubs. in summer, turning to yellow, orange and deep red in fall Additional info: highly prized by gardeners and birds for delicious fruit I. Payne
Garden use: shrub border; ALTERNATIVE Garden use: border, low hedge; ALTERNATIVE garden ornamental; native plant Growing conditions: hot, gardens, pollinator gardens dry conditions in full sun to Growing conditions: full shade part shade; adaptable to to full sun; dry to moist soil various soil conditions Size and shape: 2 – 4 m in Size and shape: 0.5 – 2 m in height height; 2 – 3 m wide
Flower and fruit: white to A. Oommen Flower and fruit: small yellow S. Coulber yellow flowers bloom in an flowers on male plants in early interesting spherical growth Northern Spicebush spring; red hairy clusters of fruit Fragrant Sumac pattern in early spring followed (Lindera benzoin) on female plants in late summer (Rhus aromatica) by red glossy fruits Leaves: fragrant blue-green leaves with a glossy upper surface; Leaves: emerald green, glossy vibrant orange, red or purple in autumn leaves on slender, light-green Additional info: good shrub for naturalized areas; may grow quite branches turn yellow in autumn thick and intertwined; important cover and food crop for birds Additional info: attracts birds, butterflies and other pollinators; larval host of the Eastern tiger swallowtail and spicebush A. Oommen swallowtail butterflies
25 Ontario Invasive Plant Council ontarioinvasiveplants.ca 26 Trees and Shrubs
INVASIVE ALTERNATIVE RUSSIAN OLIVE and INVASIVE Garden use: stand alone AUTUMN OLIVE originated in shrub ideal for shady areas; Asia, but are now common in planted for its fall colour and southwestern Ontario where fall blooming effect they thrive on nutrient-poor soil Growing conditions: full sun and spreads via root suckers. to partial shade; prefers cool, These shrubs can reach UNWANTED moist acidic soils; somewhat between 3 – 4 m in height in pollution tolerant J. Ruter a short period of time and are C. Evans Size and shape: 4 – 8 m tall; generally multi-stemmed. Russian and Autumn Olive multi-stemmed and wide-spreading Witch Hazel Autumn olive has deep green (Hamamelas virginiana) (Elaeagnus angustifolia & E. umbellata) Flower and fruit: showy yellow leaves with silvery undersides, flowers with spicy scent in fall; deep red to purple fruit, and a seedpods persist through winter and can eject seeds when touched shrubbier appearance than Russian olive, with silver-white flowers producing a strong fragrance in May. Russian olive’s upper surfaces Leaves: bright to dark green; vibrant yellow colour in fall of the leaves are light green and covered with silvery star-shaped compliments late blooms hairs, with yellow clustered flowers. Additional info: the only Canadian tree or shrub to bloom in fall; the flowers (ie. nectar and pollen), foliage, and sap of this shrub benefit a surprising diversity of pollinators including several species of wasps, bees, flies, weevils, beetles and moths
Garden use: screen; mass ALTERNATIVE Garden use: Fast-growing ALTERNATIVE planting; wildlife planting decorative shrub, screen or hedge Growing conditions: part to Growing conditions: full sun; moist to dry soils tolerates a range from sun to shade; grows best in wet to Size and shape: 1 – 3 m in moist soils height Size and shape: 1.5 – 4 m tall Flower and fruit: small fragrant and 1.5 m wide yellow flowers in spring followed J. Wilkinson I. Payne by silver berry later in summer Flower and fruit: clusters of Silverberry small white flowers blooming Leaves: narrow leaves covered Red-osier Dogwood (Elaeagnus commutata) in early summer; white berries (Cornus sericea) in fine, white hairs giving a attract birds and other wildlife silvery appearance Leaves: dark green foliage Additional info: this shrub will sucker with little effort to form groves turns red to purple in the fall; stems retain vibrant red colour Additional info: showy red twigs are a favourite for centrepieces and other decorative displays; historic uses of this plant F. Whitten include cordage, basketry and dye making; commonly used for shoreline stablization; can spread quickly
27 Ontario Invasive Plant Council ontarioinvasiveplants.ca 28 Trees and Shrubs
Garden use: shrub border; ALTERNATIVE JAPANESE BARBERRY has INVASIVE small flowering tree; garden been introduced for garden use, ornamental; native plant as well as incline stabilization gardens, pollinator gardens and erosion control. Growing conditions: full sun This 1 – 1.5 m tall bush grows to full shade; moist soils in a rounded form and has thorns along its many branches. UNWANTED Size and shape: generally, Barberries are prolific seed 2 – 4 m in height I. Payne producers and have germination B. Slattery Flower and fruit: flat-topped rates as high as ninety percent. Japanese Barberry clusters of white, lacey flowers Native Viburnums (Viburnum lentago, V. lantanoides and others) The seeds ripen in fall, persist (Berberis thunbergii) followed by berries which on the shrub through winter, are change from red to blue carried long distanced by birds, Leaves: green during growing season followed by yellow-bronze and take root in natural areas. display in fall Barberries are adapted to all soil types, can survive in full sun or full Additional info: attractant of gamebirds, songbirds and mammals shade, and have shown an ability to acidify soil thereby affecting which eat the fruit and browsers which eat twigs and leaves; host native habitats. to the spring azure butterfly
THESE NON-NATIVE INVASIVE Garden use: specimen ALTERNATIVE HONEYSUCKLES are originally planting; single shrub or hedge range from central Asia through Growing conditions: full sun the mountains of Europe. to part shade; best in well- They have all shown an invasive drained, slightly acidic soils tendency, with rapid growth Size and shape: up to 1 m tall and high reproduction ,taking UNWANTED and 2 m wide over large natural areas. Flower and fruit: small, These multi-stemmed plants R. Webb K. Powell bell-shaped flowers that start range from 2 – 5 m tall and Tartarian, Amur, as yellow-green and can turn Native Bush Honeysuckles wide at maturity, and have Morrow, Bells, to purple-red throughout (Diervilla lonicera) simple leaves that remain green European Fly Honeysuckle the summer; flowers attract through the fall. Summer leaf (Lonicera tatarica, L. maackii, bumblebees and other pollinators colour is fairly similar among L. morrowii, L x. bella, L. xylosteum) these four ranging from a blue- Leaves: dark green leaves turning yellow to red in the fall green to dark green. The flowers range in colour from white to pink Additional info: attracts and provides shelter for a diverse wildlife to crimson. community including hummingbirds, grouse and other wildlife; drought tolerant
29 Ontario Invasive Plant Council ontarioinvasiveplants.ca 30 Trees and Shrubs
MULTIFLORA ROSE is usually INVASIVE Garden use: specimen ALTERNATIVE formed as a fountain-shaped planting; edible ornamental shrub, or as a scrambling shrub Growing conditions: sun to climbing over other plants to a partial shade; wide moisture height of 3 – 5 m. and soil tolerance Originally from Japan it was Size and shape: 30 – 150 cm introduced to North America UNWANTED tall shrub as a soil conservation measure due to its adaptability to L. J. Mehrhoff Flower and fruit: showy W. D. Bakowsky different soil conditions, cream to pink flowers in spring salt tolerance, and ease of Multiflora Rose and early summer; orange to Wild Roses transplanting. (Rosa multiflora) red “rose hips” (Rosa carolina, R. virginiana) Multiflora rose is distinguished Leaves: medium green leaves from native North American roses by its fragrant white flowers growing from small-thorned branches that are arranged in clusters of more than ten flowers, whereas Additional info: edible rosehips commonly used to make tea native roses rarely exceed three per cluster. Multiflora rose is spread by birds and is a prolific seed producer. It can re-sprout roots from stems that come in contact with soil. It readily invades open areas and forms dense thickets, replacing native vegetation.
Garden use: border shrub; ALTERNATIVE Garden use: garden ALTERNATIVE screening or hedgerow ornamental, native plant garden, pollinator garden, and Growing conditions: sun to rain gardens shade; average to moist soil Growing conditions: partial Size and shape: 1 – 2 m tall to full sun; moist to wet soil Flower and fruit: small Size and shape: multi-stemmed whitish flowers, with a slight shrub reaching 2 – 4 m in height bell-shape, in spring, and fruit J. Mason E. Scharf in late summer Flower and fruit: sweet- Wild Black Currant scented white globes (~ 3 cm Buttonbush Leaves: foliage is green (Ribes americanum) wide) lend this plant its name (Cephalanthus occidentalis) throughout the season Leaves: paper-green texture Additional info: berries are nutritious (high in Vitamins A and C), with glossy appearance arranged in whorls of three and an important food source for birds Additional info: great attractant to pollinators as flowers contain an abundance of nectar and pollen
31 Ontario Invasive Plant Council ontarioinvasiveplants.ca 32 Trees and Shrubs
Despite the fact that SEA INVASIVE Garden use: shrub borders, ALTERNATIVE BUCKTHORN is used as a niche small flowering tree, hedges agricultural crop in Ontario, Growing conditions: full sun there are numerous unplanted to shade; moist to dry sites populations that demonstrate clear invasive tendencies. Outside Size and shape: 4 – 5 m tall; of cultivation, this fast-growing irregular to rounded form with UNWANTED shrub quickly forms dense upright branching impenetrable thickets that choke K. Borrowman Flower and fruit: dense, S. Coulber out native plants and wildlife. showy cream-white flower Its large 2 – 3 inches thorns Sea Buckthorn clusters 5 – 10 cm wide in Nannyberry are able to pierce protective (Hippophae rhamnoides) spring; hanging clusters of (Viburnum lentago) clothing, making management edible 1 cm long fruit change of this invasive shrub slow and costly. Although the berries are from green through yellow, pink, rose and finally blue-black heralded for their high nutrient density, there is no credible Leaves: light green maturing to dark, glossy green; deep maroon documentation that suggests sea buckthorn provides as much to red in fall wildlife value as preferable native berry producing shrubs. Some populations in Ontario can be traced back to nearby sea Additional info: a very versatile species capable of growing in full buckthorn cultivation, or intentional plantings for ornamental shade or open sites; grows as a shrub or small tree if pruned; fruit purposes. Left uncontrolled this species demonstrates a credible are used by birds and wildlife and can be eaten off the branch risk to spread beyond intended planting areas and should be avoided.
Garden use: border shrub; ALTERNATIVE Garden use: border shrub; ALTERNATIVE screening or hedgerow screening or hedgerow Growing conditions: full sun Growing conditions: full sun to partial shade; normal to to partial shade; dry to wet soil; moist soil; drought tolerant; drought tolerant; salt tolerant salt tolerant; tolerant of Size and shape: 1.5 – 3 m compacted soils tall; rounded shrub Size and shape: 1 – 3 m tall; Flower and fruit: small multi-stemmed, suckering shrub F. Whitten D. Gardens yellowish catkins appear in Flower and fruit: white to Chokeberry spring; waxy, bluish-white Bayberry whitish pink flowers produced (Aronia melanocarpa) berries with strong aromatic (Morella (syn. Myrica) pensylvanica) in clusters in early spring; scent ripen in summer and bluish-black berries produced in early fall, staying on the plant persist on the branches through the winter Leaves: leaves are dark green, waxy and fragrant with yellow resin Leaves: glossy, bright green leaves; alternate and simple; beautiful dots on the underside; deciduous to semi-evergreen; alternate fall foliage ranges in colour from crimson to apricot Additional info: the berries were used as a source of wax for early Additional info: the name “chokeberry” is derived from the edible settlers; the scent is still used in candle making but bitter tasting berries
33 Ontario Invasive Plant Council ontarioinvasiveplants.ca 34 Trees and Shrubs
Garden use: small specimen ALTERNATIVE Garden use: fast-growing ALTERNATIVE planting with edible fruit for specimen planting; screen or birds and people hedge; edible ornamental Growing conditions: full sun to Growing conditions: full sun; part shade; prefers disturbed soils moist soils Size and shape: 4 – 10 m tall; Size and shape: 2 – 4 m tall multi-stemmed small tree or large with rounded crown; multi- shrub with 3 – 5 m wide crown stemmed with open branching F. Whitten I. Payne Flower and fruit: cylindrical Flower and fruit: large clusters of small white aromatic Chokecherry (18 – 26 cm wide) clusters of Common Elderberry flowers in spring; small, red- (Prunus virginiana) cream-white flowers in early (Sambucus canadensis) purple cherries in late summer summer; purple-black edible fruit in late summer Leaves: glossy dark green in summer; yellow in fall Leaves: bright green leaves with seven leaflets Additional info: important commercial food crop used in jellies, juices, preserves and syrup; chokecherry is used in many land Additional info: transplants easily; suitable for rough sections of reclamation projects and on erosion-prone and riparian areas due garden; some have used fruit in jams, juice, jelly and wine to its extensive root mass
Garden use: stand alone shrub, ALTERNATIVE Garden use: specimen ALTERNATIVE screen or hedge planting; naturalized areas; screen or hedge Growing conditions: full sun to partial shade; adaptable to Growing conditions: partial various soil types shade with moist soil; full sun acceptable if site is cool and moist Size and shape: 2 – 3 m tall and wide; dense and rounded Size and shape: 5 – 6 m tall; with age prominently tiered branching S. James with loose crown S. James Flower and fruit: white to pink domed flower clusters in sping; Ninebark Flower and fruit: small, Alternate-Leaf Dogwood dry red-brown pods in fall (Physocarpus opulifolius) fragrant white flowers in flat (Cornus alternifolia) clusters in spring; small fruit Leaves: medium-green; vibrant changing from green to red to blue-black in summer; fruit stalks yellow-bronze in fall persistent through winter with bright coral red colour Additional info: very Leaves: prominently veined, alternate, deep green leaves typically hardy and adaptable shrub, in whorled clusters at branch tips offering winter appeal with exfoliating bark; numerous Additional info: desirable for its tiered branch structure, lending colour variations are available to its other common name “Pagoda dogwood” commercially across Ontario I. Payne
35 OntarioOntario Invasive Invasive Plant Plant Council Council ontarioinvasiveplants.ca 36 Vines
JAPANESE HONEYSUCKLE INVASIVE Garden use: climbing vine, ALTERNATIVE VINE is native to Japan and groundcover or screen Korea, and was introduced as a horticultural species. Growing conditions: sun to full shade; moist soil, but can Not to be confused with the be grown in drier conditions similarly named invasive shrub, this climbing vine is evergreen to Size and shape: dense, semi-evergreen; the vines reach UNWANTED woody, multi-stemmed, lengths of 24 m and grow either climbing vine; can reach over by climbing over other vegetation C. Bargeron 12 m in length F. Whitten or trailing along the ground. Japanese Honeysuckle Vine Flower and fruit: white Virginia Creeper Pairs of fragrant, tubular flowers (Lonicera japonica) flowers bloom in late spring/ (Parthenocissus quinquefolia) can range in colour from white early summer; dark bright blue to yellow and are found at leaf axils along the stem. fruit is produced in the early fall This vine can cover and kill trees either by toppling them from the Leaves: leaves composed of five leaflets, arranged palmately (like weight of the vines, or by blocking out sunlight. fingers spread out from the palm of your hand); leaves vibrant red in fall It spreads rapidly through runners and by long-range seed dispersal by birds and other animals. It out-competes native species for Additional info: this native vine can be an aggressive spreader, habitat, sunlight, and nutrients. but regular pruning will keep it in check; handling this plant may cause skin irritation for some people
Garden use: climbing vine; Garden use: climbing vine; groundcover; can also be ALTERNATIVE can be trained into shrub form ALTERNATIVE trained as a shrub Growing conditions: full sun Growing conditions: partial to partial shade; moist soil to full shade; moist to well- Size and shape: 4 – 6 m in drained soil length; climbs by twining stems Size and shape: grows Flower and fruit: fragrant 9 – 12 m in length, 1 m tall tubular pink-purple flowers with when trained as a shrub; S. James yellow centres; grow in terminal S. James climbs by clinging with aerial whorls; blooms throughout roots; prominent lateral Climbing Hydrangea much of the growing season Goldflame Honeysuckle branches spread from the (Hydrangea anomala ssp. petiolaris) from late spring until early fall (Lonicera x heckrotti) support structure Leaves: pairs of round, blue-green leaves Flower and fruit: large flat-topped clusters of fragrant white flowers; blooms early spring until late summer Additional info: attractive to hummingbirds and butterflies Leaves: dark green glossy leaves; heart-shaped and serrated; persist until late fall Additional info: attractive to birds, wildlife, and bees; new plants may take a few years to establish, but grows quickly afterwards and gets large with age
37 Ontario Invasive Plant Council ontarioinvasiveplants.ca 38 Vines
ORIENTAL BITTERSWEET INVASIVE Garden use: climbing vine; ALTERNATIVE is native to Asia and was ground cover introduced in the 1860s as a Growing conditions: full sun, garden ornamental. roots require mulch or shaded This brown, woody vine can grow area; light loam; moist soil up to 18 m in length and climbs Size and shape: twining vine; by twining around supports. UNWANTED 3 – 4 m in length The fruits turn from green to Flower and fruit: large yellow and split open in the F. Whitten S. Smith velvety dark purple flowers; fall to reveal very attractive Oriental Bittersweet bloom late summer to early Jackman Clematis bright red-orange seeds, the (Celastrus orbiculatus) fall; other cultivars of jackman (Clematis x jackmanii) twigs with berries are used in clematis may have red, white, flower arrangements. pink or lavender flowers However, when it escapes from gardens, oriental bittersweet may Leaves: dense foliage with bright to dark green leaves 5 – 10 cm directly compete with the rare American bittersweet (C. scandens) in length for light and space, or may hybridize with it, jeopardizing the genetic purity of the native species. This vine can kill trees, Additional info: lightly fragrant flowers smothering them and blocking sunlight.
Garden use: climbing vine; screen ALTERNATIVE Garden use: climbing vine ALTERNATIVE Growing conditions: full sun to Growing conditions: full sun partial shade; moist, well-drained to partial shade; average to soil; tolerant of urban conditions moist soil Size and shape: perennial Size and shape: twining vine; twining vine, growing 6 – 9 m grows up to 5 m in length in length Flower and fruit: white
Flower and fruit: unique pipe- V. Kempers four-petaled flowers; bloom late S. Coulber shaped yellowish flowers; bloom summer to early fall; distinctive late spring to early summer Dutchman’s Pipe fluffy white seeds remain on the Virgin’s Bower (Aristolochia macrophylla) plant through winter (Clematis virginiana) Leaves: dark green heart- shaped leaves Leaves: leaves divided into three leaflets with toothed edges Additional info: rapid growth once established; fragrant Additional info: fragrant flowers; attractive to bees, flowers attract hummingbirds, butterflies and birds bees, and butterflies; self-sows and will root where the vine touches the ground V. Kempers S. Coulber
39 Ontario Invasive Plant Council ontarioinvasiveplants.ca 40 Aquatics
INVASIVE YELLOW IRIS is native to INVASIVE Garden use: ornamental, native ALTERNATIVE Eurasia but can now be found plant garden, pollinator garden throughout southern Ontario. Growing conditions: partial Occurring in shallow water to full shade; rich, moist soils along streams, rivers, ponds (will tolerate standing water) and lakes, it was likely Size and shape: 1 – 2 m tall; introduced as an ornamental UNWANTED upright groups with spreading garden plant in ponds and habit of growth outdoor water gardens. L. Mehrhoff S. Coulber Flower and fruit: showy This riparian perennial has Yellow Flag Iris spikes of scarlet flowers Cardinal Flower erect leaves and brightly (Iris pseudacorus) (excellent for cuttings) bloom (Lobelia cardinalis) coloured showy flowers. July to September Once established, yellow iris Leaves: pointy, lance-shaped leaves along entire stem until can form a dense stand which reaching flower displaces native shoreline vegetation and converts wet Additional info: flowers attract many pollinators, including habitat to drier environments. hummingbirds Plant sap may cause skin blistering. N. Loewenstein
Garden use: ornamental in ALTERNATIVE Garden use: garden accent, ALTERNATIVE ponds and water gardens, used container planting, native plant for shoreline enhancement garden, rain garden, groundcover Growing conditions: along Growing conditions: part to shores and in marshes, swamps, full sun; moist to wet soil wet meadows and occasionally Size and shape: 0.5 – 1 m fens; in water up to 2 m deep in height Size and shape: stems R. Gray Flower and fruit: W. Bakowsky 20 – 80 cm tall, growing in inconspicuous small green/ small colonies Northern Blueflag Iris brown flowers Sweetflag Grass Flower and fruit: showy, (Iris versicolor) (Acorus calamus) Leaves: medium green, slender blue-purple flowers with radiating from central base yellowish veins separated into 3 petals; fruit capsules 2 – 3 cm long with flat seeds stacked inside, turning brown in autumn Additional info: spreads slowly via rhizomes, and the leaves have a light, sweet scent when crushed Leaves: elongated, with parallel veins, up to 3 cm wide Additional info: root stocks are poisonous; flowers are pollinated by bees; muskrats, beavers and birds feed on flower nectar
41 Ontario Invasive Plant Council ontarioinvasiveplants.ca 42 Aquatics
Native to Eurasia, FLOWERING INVASIVE Garden use: habitat and ALTERNATIVE RUSH can now be found in shoreline enhancement of Ontario throughout Lakes Erie, ponds and water gardens St. Clair, Ontario, and Superior, Growing conditions: prefers as well as in the western St. medium to moist soils, found in Lawrence River, Severn River moist fields and meadows; once and Winnipeg River systems. UNWANTED established can be found in This perennial aquatic rush may drier garden soils grow submerged or emerge W. Bakowsky E. Snyder Size and shape: ranging from above the surface, with triangular 30 – 180 cm tall with square, leaves and multiple pink flowers Flowering Rush Blue Vervain grooved stem on the end of a stalk. (Butomus umbellatus) (Verbena hastata) Flower and fruit: blue-violet Flowering rush can grow flowers, blooming from summer to fall in lakes, rivers, marshes, ponds and wet ditches. It is used as an ornamental plant for ponds and outdoor water gardens, or Leaves: oppositely arranged, 5 – 15 cm long lance-shaped leaves, intentionally planted along shorelines where it may escape and narrowed at base invade new areas. Additional info: useful for shoreline restoration or in a rain Once established, flowering rush can displace native shoreline garden; attractive to birds, butterflies and pollinating bees; young vegetation and hinder recreational use. plants are often confused with mint
Garden use: native wildflower ALTERNATIVE Garden use: great for ALTERNATIVE used in wet meadows and pollinator gardens (well-suited pond edges to edges or toward rear of landscape designs Growing conditions: moist to wet soils; sun to partial shade Growing conditions: full sun to partial shade, rich and moist Size and shape: 30 – 90 cm soil (great choice for riparian in height plantings) Flower and fruit: showy, F. Whitten S. James Size and shape: 1 – 2 m pink flowers resemble a turtles tall; flower clusters atop head, blooming through end of White Turtlehead Joe-pye Weed individual plants summer; seedcapsules remain (Chelone glabra) (Eupatorium maculatum) on stalks throughout winter Flower and fruit: showy fragrant mauve/pink flowers bloom from July to September Leaves: long, narrow leaves Leaves: 3 – 4 light-green leaves whorled in groups along stem Additional info: pollinator friendly plant; preferred host plant for the Baltimore butterfly; rarely grazed Additional info: great attractant for butterflies and other pollinators
43 Ontario Invasive Plant Council ontarioinvasiveplants.ca 44 Aquatics
Garden use: low-maintenance ALTERNATIVE Garden use: native wildflower ALTERNATIVE choice for garden ornamental found in wet meadows and (showy blooms), native plant pond edges garden, pollinator garden, and rain gardens Growing conditions: moist to wet soils; clay to loamy soils; Growing conditions: partial full sun to partial shade to full sun; wet to moist soils Size and shape: 0.5 to 1.5 m Size and shape: 1 – 2 m tall in height S. Coulber K. Powell Flower and fruit: large white Flower and fruit: large flower to pink flowers with darker centre Swamp Rose-mallow heads comprised of many Swamp Milkweed bloom from July to September (Hibiscus moscheutos) smaller pink to rose-purple (Asclepias incarnata) Leaves: grey-green leaves flowers; blooming mid-summer Additional Info: pollinated by native long-tongued bees through early fall including the specialist Rose Mallow Bee; blooms also provide Leaves: narrow, lance-shaped leaves nectar to ruby-throated hummingbirds and a variety of insects. The swamp rose-mallow is a species at risk in Ontario, and classified Additional info: this species offers ample educational as “Special Concern” opportunities for youth, being one of the few host species for caterpillars of the native monarch butterfly
Garden use: native plant ALTERNATIVE Garden use: perennial water ALTERNATIVE gardens; pollinator gardens loving wildflower Growing conditions: partial to Growing conditions: moist to full sun; wet to moist conditions wet soils Size and shape: 50 – 100 cm Size and shape: up to 0.5 m tall tall; grows in clumps and bunches through rhizome network Flower and fruit: brilliant yellow flower bloom in early Flower and fruit: clusters of spring, April to June tiny, cream-white fuzzy flowers K. Powell K. Powell Leaves: long stalked, toothed, are arranged at the tops of Boneset Marsh Marigold flower stocks, with branching (Eupatorium perfoliatum) kidney shaped basal leaves (Caltha palustris) flowering side stems, bloom Additional info: early late summer to early fall blooming flowers are a sure sign of spring; attracts pollinators Leaves: lanceolate with long narrow tips and toothed margins; stem appears to emerge through the clasped leaves Additional info: great butterfly attractant (ie. painted lady butterfly)
45 Ontario Invasive Plant Council ontarioinvasiveplants.ca 46 Aquatics
WATER LETTUCE is an aquatic INVASIVE Garden use: ornamental in ALTERNATIVE plant known to be problematic ponds and water gardens, used in central America and Southern for shoreline enhancement US states such as Florida. Growing conditions: shallow Although many believed this water (rarely more than 1 m plant is unable to successfully deep) along muddy or sandy overwinter in Ontario, there is UNWANTED shores of lakes, ponds, marshes, evidence this may no longer rivers and streams be true. Repeated annual F & K Starr S. James detections in Lake St. Clair Size and shape: stems erect, may suggest the species is Water lettuce stout, 30 – 60 cm tall growing Pickerelweed able to overwinter and form (Pistia stratiotes) from thick spreading root (Pontederia cordata) low-density stands in at least system often forming dense some regions of Ontario. These colonies in still waters findings, plus the considerable impacts inflicted by the species in its Flower and fruit: flowers violet-blue with 2 yellow dots on upper lip, invasive range make it a species to avoid. funnel-like, about 8 mm long; 1 – seeded bladder-like fruit with 1 seed Leaves: lance to egg shaped, heart shaped at base, 5 – 25 cm long, 2 – 5 cm wide Additional info: young stems and leaves of pickerelweed can be eaten in salads or boiled and served with butter; seeds can also be eaten raw; pollinated by bees and butterflies
WATER SOLDIER is an aquatic INVASIVE Garden use: oxygenation, ALTERNATIVE plant once commonly sold in the habitat enhancement for ponds water garden industry. Water and water gardens soldier is now regulated as a Growing conditions: Prohibited invasive species under submerged or above surface, Ontario’s Invasive Species Act. aquatic found in lakes, ponds, (see regulation details on page 6). PROHIBITED marshes, streams and rivers, This plant is native to Europe and sometimes on peat in fens; muddy Central Asia. Currently the only Wikipedia Commons substrate; prefers non-acidic J. Viola two known wild populations of conditions water soldier are located near Lake Water soldier Common Mare’s Tail Simcoe and in the Trent River. (Stratiotes aloides) Size and shape: stems thick, (Hippuris vulgaris) soft, erect, 10 – 50 cm tall, from Water soldier, also known as water spongy roots aloe, looks very similar to an aloe vera plant, or the top of a pineapple plant. Flower and fruit: Flower: very small, lacking sepals and petals in axils of Water soldier grows underwater on the river bottom most of the year, and upper leaves, rare and occur in the summer; Fruit: nutlet, ellipsoidal, 1.7 – emerges in late spring and summer. 2.5mm long occurring mid-to late summer. The leaves that grow once it has surfaced have air pockets enabling the Leaves: when breaking water surface, 1 – 2 cm long thick, firm and plant to float. Water soldier forms dense populations with large masses of spiky whorls of 6 – 12; when submerged, 1 – 3 cm long thin and weakly plants which out-compete other aquatic plant species. attached, dropping when removed from water A notable concern is that each leaf is lined with small serrated spines that Additional info: marsh birds occasionally feed on the leaves and stems can easily cut swimmers. of common mare’s tail; Hippuris means horse’s tail
47 Ontario Invasive Plant Council ontarioinvasiveplants.ca 48 Aquatics
EUROPEAN FROG-BIT is INVASIVE Garden use: ornamental in ALTERNATIVE native to Eurasia but can ponds and water gardens; great now be found from the St. for shoreline enhancement Lawrence River to Lake Ontario, Growing conditions: prefers throughout the Kawartha Lakes, shallow water or very wet soil the Rideau and Ottawa River along muddy shores of lakes, and systems and along Lakes Erie UNWANTED marshes; grows best in full sun and St. Clair. Size and shape: attains heights of It is also spreading northward D. Laxton K. Chayka 30 – 120 cm above water; emergent at scattered sites throughout leaves are arrowhead shaped the Canadian Shield, and has European Frog-bit Broad-leaved Arrowhead been found as far north as (Hydrocharis morsus-ranae) Flower and fruit: three-petaled (Sagittaria latifolia) Dryden, Ontario. white flowers with yellow centre are found in whorls of three and bloom from July to September; leaves It grows free-floating or as a rooted mat in shallow waters. Roots and flowers are found on separate stalks; fruit is a head of beaked can grow up to 50 cm long with numerous root hairs. seeds, dark brown in colour Leaves are floating and form a rosette; white-pink flowers emerge Leaves: most noted for its arrowhead-shaped leaves, they can be quite in summer. variable in size; emergent leaves grow up to 30 cm and submerged leaves are much smaller and narrower Additional info: sometimes known as duck potato, referring to its enlarged, rounded tubers that form at the end of the plants runners, they float to the surface when dislodged and can be boiled or baked and eaten like a potato; great food source for wildlife and helps stabilize shorelines
Native to Southern Europe and INVASIVE Garden use: ornamental in ALTERNATIVE Asia, YELLOW FLOATING ponds and water gardens; HEART was originally thought provides shade for fish to only occur in ponds Growing conditions: lakes, connecting to the Rideau Canal ponds, slow rivers and marshes; in Ottawa, but more recently an variety of sediment types established population has been UNWANTED found near the Credit River in Size and shape: round stems rise Mississauga. toward water surface from fleshy G. Bales rhizome buried in the sediment; K. Powell This floating plant with heart- grows in water depths up to 2 m shaped leaves and bright yellow Yellow Floating Heart Fragrant Water Lily flowers is a rooted perennial (Nymphoides peltata) Flower and fruit: white, showy, (Nymphaea odorata) that prefers slow moving rivers fragrant flowers 7 – 20 cm wide, and lakes, ponds and canals. open only from mid-morning to early afternoon throughout summer; flower produced on separate flower stalks growing directly from the It can establish in mud and in water up to 4 m deep. When it grows rhizome; cultivars may also have pale pink flowers; leathery berries with in thick floating mats, it can create stagnant water with low oxygen many seeds ripening underwater in mid to late summer levels, thus degrading fish habitat and limiting recreational activities. Leaves: floating, round lily-pad with narrow V-shaped split; underside of leaf is reddish purple Additional info: waterfowl eat fruit and seeds; roots are eaten by mammals
49 Ontario Invasive Plant Council ontarioinvasiveplants.ca 50 Aquatics
FANWORT, also called INVASIVE Garden use: oxygenation, ALTERNATIVE Cabomba, is native to the sub- habitat enhancement for ponds tropic and temperate regions of and water gardens South America.This submerged Growing conditions: perennial plant is very popular submerged aquatic found in in the aquarium industry and lakes, ponds, streams, marshes is widely available through pet UNWANTED and quiet rivers; overwinters as stores across Ontario. an evergreen under ice; tolerant The first report of an established D. Sutherland to low light and cool water R. Canning population of fanwort in Size and shape: coarse, Ontario was in Kasshabog Lake Fanwort Coontail branching stems and no roots; in 1991. It is currently found (Cabomba caroliniana) (Ceratophyllum demersum) may drift and become loosely in a number of small nearby, anchored in sediment landlocked lakes. Flower and fruit: very small, stalk-less solitary flowers on Fanwort has finely dissected, fan-shaped submerged leaves and submerged leaves; fruit is dark olive green, elliptic small inconspicuous linear or rounded floating leaves. The flowers are small, white to pale yellow and have three petals. Rooted in Leaves: split into 2 equal, thread-like segments; sharply toothed; substrate, this plant flourishes in slow flowing waters in streams, in whorls of 5 to 12; leaves get denser at the end of the stem and small rivers, ponds and lakes. Fanwort is extremely persistent look like a raccoon’s tail once established and can form dense stands, displacing native Additional info: provides food and shelter for invertebrates; can vegetation, and impeding drainage in canals and streams. become abundant in shallow ponds and form large beds; also known as hornwort; reproduces through fragmentation
HYDRILLA, also called water INVASIVE Garden use: oxygenation, ALTERNATIVE thyme, water weed, and Florida habitat enhancement for ponds elodea is native to Asia and and water gardens can be found in rivers, lakes, Growing conditions: submerged ponds, streams and wet ditches. perennial plant, common in still and Hydrilla is now regulated as fast-flowing waters; grows from a Prohibited invasive species PROHIBITED underground runners under Ontario’s Invasive Species Act (see regulation details on Size and shape: large, Louisiana Sea Grant R. Canning page 6). often forms tall underwater “meadows”; upper leaf parts are This invasive plant resembles Hydrilla Tape grass sometimes found floating across Ontario’s native waterweeds (Hydrilla verticillata) (Vallisneria americana) the water surface (Elodea canadensis and E. nuttallii) but can be distinguished by the presence of prickles on Flower and fruit: produces small, white flowers on very long stalks lower leaf surfaces. and mature flowers can reach the surface of the water; fruit is a banana-like capsule having many tiny seeds Although there are no documented populations of hydrilla in Ontario, it presents a significant threat to aquatic ecosystems and navigation. Leaves: 2.5 cm wide and can be several m long; definite raised veins with some cross veins; rounded tips Additional info: consumed by various animals and provides habitat for many species; can assist with stabilizing sediment and shorelines and improving water quality
51 Ontario Invasive Plant Council ontarioinvasiveplants.ca 52 Additional Non-Invasive Alternatives
I. Payne S. Coulber R. Videki R. Rutledge
Red Oak Bergamont Canada Waterweed Common Arrowhead (Quercus rubra) (Monarda) (Elodea canadensis) (Sagittaria latifolia)
S. Coulber S. Coulber F. Whitten S. Coulber
Golden Alexander Great Blue Lobelia Lady Fern Dense Blazing Star (Zizia aurea) (Lobelia siphilitica) (Athyrium filix-femina) (Liatris spicata)
S. Coulber J. Ruter S. Coulber Plants Factory
Maidenhair Fern Shrubby Cinquefoil Prairie Smoke Dwarf Hairgrass (Adiantum aethiopicum) (Dasiphora fruticose) (Geum triflorum) (Eleocharis acicularis)
53 Ontario Invasive Plant Council ontarioinvasiveplants.ca 54 Watch List Additional Resources The following species are additional horticulture plants to be on alert Bringing Nature Home for in Ontario. Gardeners should be aware that these species can be bringingnaturehome.net invasive in natural areas: In The Zone Gardens Pachysandra (Pachysandra terminalis) inthezonegardens.ca Japanese Lilac (Syringa reticulata) Canadian Wildlife Federation Mint spp. (Lamium spp.) wildaboutgardening.org American Wisteria (Wisteria frutescens) Guelder Rose/ European Cranberry (Viburnum opulus) North American Native Plant Society Sycamore Maple (Acer pseudoplatanus) nanps.org Callery Pear (Pyrus calleryana) Winter Aconite (Eranthis hyemalis) OFAH / Invading Species Awareness Program Jetbead (Rhodotypos scandens) invadingspecies.com Chocolate Vine (Akebia quinata) Invading Species Hotline: 1-800-563-7711 Japanese Hedge Parsley (Torilis japonica) Spreading Hedge Parsley (Torilis arvenis) Ontario Invasive Plant Council Giant Knotweed (Reynoutria sachalinensis) ontarioinvasiveplants.ca Bohemian Knotweed (Reynoutria × bohemica) Common and Chinese Privet (Ligustrum vulgare, L. sinense) Ontario Ministry of Natural Resources and Forestry Japanese Knotweed (Reynoutria japonica) ontario.ca/invasivespecies Kudzu (Pueraria montana) Invasive Species Centre Reed Canarygrass (Phalaris arundinacea var. picta) invasivespeciescentre.ca Parrot Feather (Myriophyllum aquaticum) Saltcedar/Tamarisk (Tamarix ramoisissima) Pollinators of Native Plants Siberian Peashrub (Caragana arborescens) pollinatorsnativeplants.com Tree-of-Heaven (Ailanthus altissima) Water Chestnut (Trapa natans) White Mulberry (Morus alba) Water Hyacinth (Eichhornia crassipes) Phragmites (Phragmites australis subs. australis) Dog-strangling Vine (black and pale swallowwort) (C. louiseae and C. rossicum) Brazilian Elodea (Egeria densa) Water Soldier (Stratiotes aloides) Hydrilla (Hydrilla verticillata)
Jessica Rose Powell
55 Ontario Invasive Plant Council ontarioinvasiveplants.ca 56 Thank you... Notes
We would like to thank the following organizations and companies for contributing photographs, expertise, time, and funding for printing towards the development of Edition 3, 2020 of the Grow Me Instead Guide for Southern Ontario: Canadian Wildlife Federation Central Lake Ontario Conservation Authority City of Guelph City of Toronto Conservation Halton Credit Valley Conservation Durham Region Ground Covers Unlimited Lake Simcoe Region Conservation Authority Landscape Ontario Not So Hollow Farm Quinte Conservation Regional Municipality of York Sean James Consulting & Design WSP Canada Ltd.
Jessica Rose Powell
57 Ontario Invasive Plant Council ontarioinvasiveplants.ca 58 2 colour printing
4 colour printing
black only