Invasive plants are taking hold of our natural areas, choking out other plants and related animal life. Our job as gardeners is to keep invasive plants out of our yards to avoid any possible spread and grow beneficial plants instead.
For help researching plants, I have listed some online plant databases here.
How Gardeners Can Help Fight Invasive Plants
Invasive English Ivy
GROW NO HARM
As gardeners and caretakers of the earth, this is our first responsibility: grow no harm.
Years ago the topic of invasive plants rarely came up in garden how-tos but as things are today, invasiveness should be our first concern when selecting plants.
Our entire eco-system depends on natural checks and balances between plants and animals.
This is the circle of life: biodiversity and sustainability.
When invasive plants take over, our natural habitats are altered or gradually destroyed.
I didn’t think twice about this stuff when I started gardening many years ago, and now it’s the center of my garden choices.
Invasive plants gradually choke out adapted, non-aggressive plants and the animals they have co-evolved with.
Without predators or natural containments, these thugs are gradually destroying our natural areas.
Jump to: Invasive Plant List and Alternative Choices
The bee gets the pollen or nectar, the flower is pollinated. It’s win win.
So What Does This Have to Do With Home Gardening?
What we grow in our gardens is what we grow everywhere.
There are a lot of us gardeners! Together we have tremendous power to influence the gardening industry and decide how our gardens will or will not contribute to the well-being of the earth.
Many invasive species we struggle with today were introduced by humans—either intentionally or incidentally, or by wind or animals.
And, no matter how much we try to contain things or think we can control it in our own yards, plants can always spread.
This could be by pollination, natural propagation such as a bird pooping out a seed, roots spreading to neighboring yards, disposal of the plant or clippings in yard waste which ends up growing elsewhere, and countless other ways. Most often it is done innocently or unknowingly, but either way, it is a problem.
If we grow it in our gardens we have to assume it can and will be released into nature.
Get to Know Your Local Invasive Species
As a gardener, I encourage you to look up invasive species resources for your region and get familiar with the major players. In many cases, borders on a map are meaningless: some of these problems cover vast areas of our continent.
Invasive Lily of the Valley
Have you got any invasive plants growing in your garden?
I do! And removing them is an ongoing project.
A big clue is often if the plant is both hardy and fast-growing or spreads rapidly. Anything fast or really easy to grow can spell trouble.
The most startling thing is that while environmental and conservation groups are battling these invasive species if/as funding allows (which fluctuates depending on the political parties in charge), a bunch of these plants are still sold at plant nurseries. As informed consumers we can help stop this.
Not all invasives in natural areas are caused by gardeners of course, but over the years we have certainly played a role.
Using ‘native plants‘ is part of the solution. But beware that it’s not that simple.
Just because it’s labelled native for your region does not mean it is suited to your specific garden climate and growing conditions. And some native species can be aggressive growers too. It’s always about the right plant in the right place.
On the flip side, not all introduced species, hybrids, cross-breeds, and cultivars are invasive—not by any measure. But they may be sterile or infertile and not provide any benefit to birds, bees, butterflies, and so on. So it’s worth researching plants before purchasing.
Ultimately what we need are non-invasive, non-aggressive plants that fit our climate and growing conditions and have a symbiotic relationship with other non-invasive living things. Grow to restore those natural checks and balances as much as we can.
It’s a lot to consider but the reward is a vibrant, thriving garden that does no harm. Or at least helps prevent further invasion.
Wait! Before You Plant…
Plant Buying Checklist
Recommended for your growing zone.Not invasive in your area.Suits your growing conditions including sun, soil, water, and wind.Contributes to biodiversity by providing food, nectar, or habitat.
Southern Ontario Invasive Plants and Alternate Choices
Invasive plants can be terrestrial or aquatic including annuals, perennials, trees, shrubs, and vines.
These lists show common invasive plants for southern Ontario, Canada and surrounding regions and provides some alternative plant choices.
I have compiled these lists from the resources listed here.
Again, be sure whatever you choose is non-invasive and (preferably) non-aggressive, is well-adapted for your area and growing conditions, and has a symbiotic relationship with local wildlife.
Groundcovers, Wildflowers, and Grasses
Invasive PlantRecommended AlternativeBugleweed
Ajuga reptansWild Ginger
Asarum canadenseCreeping Jenny
Hemerocallis fulvaMichigan Lily
Pale Purple Coneflower
Rudbeckia hirtaEnglish Ivy
Hedera helixWild Strawberry
Aegopodium podagrariaLarge-leaved Aster
Convallaria majalisStarry Solomon’s Seal
Maianthemum stellatumMiscanthus Grasses
Vinca minorWild Geranium
Hydrophyllum virginianumYellow Archangel
Lamiastrum galeobdolonZigzag Goldenrod
Trees, Shrubs, and Vines
Invasive PlantRecommended AlternativeAmur Maple
Acer ginnalaRuby Lace Honeylocust
Gleditsia triacanthos var. inermisHoneysuckles -Non-Native
L. x bella
L. xylosteumNative Bush Honeysuckles
Diervilla loniceraHoneysuckle – Japanese Vine
Lonicera japonicaClimbing Hydrangea
Hydrangea anomala spp. petiolaris
Lonicera x heckrotti
Parthenocissus quinquefoliaJapanese Barberry
Berberis thungergiiNative Viburnums
Viburnum lentago, V. lantanoides and othersMultiflora Rose
Wild Black Current
Rosa carolina, R. virginianaNorway Maple
Acer platanoidesSugar, Silver, and Freeman Maples
Acer saccharum, A. saccharinum, A. xfreemaniiOriental Bittersweet
Celastrus orbiculatusDutchman’s Pipe
Clematis x jackmanii
Clematis virginianaRussian Olive
E. umbellataRed-osier Dogwood
Hamamelis virginianaSea Buckthorn
Hippophae rhamnoidesAlternate-Leaf Dogwood
Morella (syn. Myrica) pensylvanica
Physocarpus opulifoliusWinged Euonymus
Euonymus alatusDowny, Smooth, and Canada Serviceberry
Amelanchier arborea, A. laevis, A. canadensis
Invasive PlantRecommended AlternativeEuropean Frog-bit
Hydrocharis morsus-ranaeBroad-leaved Arrowhead
Ceratophyllum demersumFlowering Rush
Butomus umbellatusBlue Vervain
Hydrilla verticillataTape grass
Vallisneria americanaYellow Floating Heart
Nymphoides peltataFragrant Water Lily
Nymphaea odorataYellow Iris
Cardinal Flower (not aquatic)
Northern Blueflag Iris
Chelone glabraWater Lettuce
Pontederia cordataWater Soldier
Stratiotes aloidesCommon Mare’s Tail
Additional Non-Invasive Alternatives
Bergamot MonardaCanada Waterweed Elodea canadensisCommon Arrowhead Sagittaria latifoliaDense Blazing Star Liatris spicataDwarf Hairgrass Eleocharis acicularisGolden Alexanders Zizia aureaGreat Blue Lobelia Lobelia siphiliticaLady Fern Athyrium filix-feminaMaidenhair Fern Adiantum aethiopicumPrairie Smoke Geum triflorumRed Oak Quercus rubraShrubby Cinquefoil Dasiphora fruiticosa
Can Be Invasive in Natural Areas
American Wisteria Wisteria frutescensBohemian Knotweed Reynoutria × bohemicaBrazilian Elodea Egeria densaCallery Pear Pyrus calleryanaChocolate Vine Akebia quinataCommon and Chinese Privet Ligustrum vulgare, L. sinenseDog-strangling Vine (black and pale swallowwort) C. louiseae and C. rossicumGiant Knotweed Reynoutria sachalinensisGuelder Rose/ European Cranberry Viburnum opulusHydrilla Hydrilla verticillataJapanese Hedge Parsley Torilis japonicaJapanese Knotweed Reynoutria japonicaJapanese Lilac Syringa reticulataJetbead Rhodotypos scandensKudzu Pueraria montanaMint spp. Lamium spp.Pachysandra Pachysandra terminalisParrot Feather Myriophyllum aquaticum Saltcedar/Tamarisk Tamarix ramoisissimaPhragmites Phragmites australis subs. australisReed Canarygrass Phalaris arundinacea var. pictaSiberian Peashrub Caragana arborescensSpreading Hedge Parsley Torilis arvenisSycamore Maple Acer pseudoplatanusTree-of-Heaven Ailanthus altissimaWater Chestnut Trapa natansWater Hyacinth Eichhornia crassipesWater Soldier Stratiotes aloidesWhite Mulberry Morus albaWinter Aconite Eranthis hyemalisOntario Resources
Ontario Invasive Plant Council | Ontario non-profit tackling invasive plant issues
Grow Me Instead: Beautiful Non-Invasive Plants for Your Garden
A Guide for Southern Ontario (PDF format)
Grow Me Instead: Beautiful Non-Invasive Plants for Your Garden
A Guide for Northern Ontario (PDF format)
In the Zone | Southwestern Ontario | Grow a healthy woodland, wetland or wildflower garden designed to help Carolinian wildlife thrive.
Learn what’s invasive in your region.Remove these invasives from your garden and dispose of them without risk of regrowing.Watch for invasive plants in nurseries and report them.Support local conservation efforts. ~Melissa the Empress of Dirt ♛