Frequently Asked Questions
This FAQ covers the most common questions about Minnesota native plants, from basic definitions to advanced garden design and ecological restoration. If you are new to native plants, start with the Getting Started section. Use the other sections to explore topics that interest you most.
Getting Started
What is a native plant?
A native plant is a species that has existed in a particular region for thousands of years, long before European settlement. In Minnesota, native plants are species that were growing here before approximately 1850, when large-scale agriculture and development began transforming the landscape. These plants have evolved alongside Minnesota's soils, climate, insects, and wildlife over millennia, making them uniquely adapted to local conditions.
For example, a native prairie grass like Big Bluestem (Andropogon gerardii) can send roots 10 to 15 feet deep into the soil, far deeper than any lawn grass. This deep root system allows it to survive drought, hold soil in place, and filter rainwater. Minnesota is home to over 1,800 native plant species ranging from towering White Pines in the north to delicate prairie wildflowers in the south.
What is the difference between native, non-native, and invasive plants?
A native plant is a species that has been part of Minnesota's ecological community for thousands of years. A non-native plant is one that humans introduced from another region but does not cause significant harm, such as tomatoes, tulips, or daylilies. An invasive species is a non-native plant that spreads aggressively into natural areas and causes ecological or economic harm, such as Common Buckthorn, Garlic Mustard, or Purple Loosestrife.
The key distinction is harm. Many non-native plants coexist peacefully in gardens without spreading into the wild. Invasive species, on the other hand, displace native plants, reduce wildlife habitat, alter soil chemistry, and disrupt food webs. Minnesota lists over 100 species as invasive or potentially invasive.
Why should I plant native plants instead of conventional garden plants?
Native plants offer several advantages over conventional garden plants. Because they evolved in Minnesota's climate, they are adapted to local weather extremes, including cold winters and periodic drought. Once established, they require no fertilizer, little watering, and no pesticides. Their deep root systems prevent erosion and filter stormwater runoff. Most importantly, native plants provide food and shelter for native pollinators, birds, and wildlife that non-native species often cannot support.
For example, a single native oak tree supports over 500 species of caterpillars, which in turn feed nesting songbirds. A non-native ornamental tree may support fewer than five. Choosing native plants is one of the most effective actions you can take to support biodiversity in your yard.
Do I need any gardening experience to plant native plants?
No prior gardening experience is required. Native plants are often easier to grow than conventional garden plants because they are adapted to Minnesota's conditions. The most important steps are matching the right plant to the right site (sun, soil, and moisture) and preparing the planting area properly by removing weeds beforehand.
This textbook walks you through every step, from assessing your site to selecting plants, preparing the ground, planting, and maintaining your garden over time. Start small with a few reliable species like Purple Coneflower (Echinacea purpurea), Black-Eyed Susan (Rudbeckia hirta), or Little Bluestem (Schizachyrium scoparium), and expand as you gain confidence.
What are Minnesota's USDA hardiness zones?
USDA hardiness zones describe the average annual minimum winter temperature for a given area. Minnesota spans zones 3a through 5a (per the 2023 USDA Plant Hardiness Zone Map), with zone 3a in the far north experiencing winter lows around -40 degrees Fahrenheit and zone 5a in the Twin Cities metro and southeastern counties experiencing lows around -15 to -20 degrees Fahrenheit.
When selecting plants, always check that the species is rated for your hardiness zone. A plant rated for zone 5 may not survive a zone 3 winter. Most Minnesota native plants are naturally adapted to the full range of the state's hardiness zones, which is one reason they are such reliable choices.
What are Minnesota's major ecoregions?
Minnesota sits at a remarkable ecological crossroads where three major North American biomes meet. The state contains four major ecoregions: the Tallgrass Prairie in the western and southwestern portion, the Deciduous Forest in the central and southeastern regions, the Coniferous (Boreal) Forest in the northeastern corner and Boundary Waters area, and the Prairie-Forest Border where prairie and forest intermingle in the central part of the state.
Each ecoregion supports different plant communities. Knowing which ecoregion you live in helps you choose plants that are best adapted to your local conditions. For example, a homeowner in southwestern Minnesota lives in the Tallgrass Prairie region and would focus on prairie grasses and wildflowers, while someone in the northeast would emphasize boreal forest species.
How long does it take for a native garden to become established?
Most native plantings take two to three years to become fully established. The common saying is "sleep, creep, leap" -- in the first year, plants focus on root development and may appear dormant or sparse. In the second year, you will see modest above-ground growth. By the third year, plants begin to fill in vigorously and bloom reliably.
This timeline requires patience, but the payoff is significant. Once established, native plantings require far less maintenance than conventional gardens. They do not need watering in normal years, they do not need fertilizer, and they become increasingly resilient over time. Plan for active weed management during those first two to three years, as this is the most critical period for success.
Where can I see native plant gardens in Minnesota?
Several public gardens and natural areas in Minnesota showcase native plants. The Eloise Butler Wildflower Garden and Bird Sanctuary in Minneapolis is one of the oldest public wildflower gardens in the United States and features hundreds of native species. The Minnesota Landscape Arboretum in Chaska has extensive native plant collections and demonstration gardens. Many county and city parks maintain native prairie and woodland restorations open to the public.
You can also visit prairie remnants managed by the Minnesota Department of Natural Resources (MN DNR) and The Nature Conservancy. The MN DNR's Scientific and Natural Areas program protects some of the state's finest remaining native plant communities.
What time of year is best to plant native plants?
In Minnesota, the two best planting windows are spring (mid-April through May) and fall (September through mid-October). Spring planting gives plants a full growing season to establish roots before winter. Fall planting allows roots to develop during cool, moist conditions and gives seeds the cold stratification period they need to germinate the following spring.
For native seed mixes, fall planting (late October through November) is often preferred because it mimics the natural cycle of seeds falling to the ground in autumn and germinating after winter cold breaks their dormancy. Plugs and container-grown plants can be planted in either spring or fall, with fall slightly preferred because cooler temperatures reduce transplant stress.
How much does it cost to start a native garden?
Costs vary widely depending on garden size, plant sources, and site preparation needs. A small pollinator garden of 100 square feet using plugs (small potted plants) might cost $150 to $300 for plants alone, with additional costs for site preparation materials like cardboard and mulch. Native seed mixes are more affordable for larger areas, typically $100 to $400 per acre depending on the species mix.
The largest expense is often labor for site preparation and weed management in the first few years. However, native gardens save money over the long term because they eliminate or drastically reduce costs for watering, fertilizing, mowing, and pesticide applications. Many Minnesota counties and cities offer cost-share grants for native plantings, rain gardens, and pollinator habitat through their Soil and Water Conservation Districts.
What is a rain garden and why should I consider one?
A rain garden is a shallow depression planted with native plants that captures and filters stormwater runoff from roofs, driveways, and lawns. Instead of allowing rainwater to flow directly into storm drains (and eventually into lakes and rivers carrying pollutants), a rain garden slows the water down and lets it soak into the ground where plant roots and soil microbes filter out pollutants.
Rain gardens are particularly valuable in Minnesota where stormwater runoff is a major source of pollution in lakes and rivers. Native plants with deep root systems like Joe-Pye Weed (Eutrochium maculatum), Blue Flag Iris (Iris versicolor), and various native sedges are ideal rain garden plants because they tolerate both wet and dry conditions. Many Minnesota cities offer financial incentives for rain garden installation.
Native Plant Basics
What makes tallgrass prairie plants special?
Tallgrass prairie plants are remarkable for their deep root systems, drought resilience, and ecological importance. The dominant warm-season grasses like Big Bluestem can grow six feet tall above ground, but their roots extend 10 to 15 feet or more below the surface. These deep roots build rich soil, prevent erosion, store carbon, and filter water. A healthy tallgrass prairie can support 200 to 300 plant species per acre.
Before European settlement, tallgrass prairie covered roughly 18 million acres of Minnesota, about one-third of the state. Today, less than 2 percent remains. These prairie remnants are among the most endangered ecosystems in North America, which makes planting prairie species in home landscapes an important conservation action.
What is the difference between warm-season and cool-season grasses?
Warm-season grasses (also called C4 grasses) begin growing in late spring, reach peak growth in the heat of summer, and go dormant after the first hard frost. They use a photosynthetic pathway that is more efficient in hot, sunny conditions. Examples include Big Bluestem, Little Bluestem, Switchgrass, Indian Grass, and Prairie Dropseed.
Cool-season grasses (C3 grasses) grow most actively in spring and fall when temperatures are moderate. They green up earlier in the season and provide important early cover and food for wildlife before warm-season grasses emerge. A well-designed native planting includes both types to provide year-round ground cover and ecological function.
What are spring ephemerals?
Spring ephemerals are woodland wildflowers that complete their entire above-ground life cycle in a few short weeks during early spring, before the tree canopy leafs out and blocks sunlight from the forest floor. They emerge, bloom, set seed, and die back to their underground roots or bulbs by late May or early June.
Common Minnesota spring ephemerals include Bloodroot (Sanguinaria canadensis), Trillium (Trillium grandiflorum), Hepatica (Hepatica americana), Dutchman's Breeches (Dicentra cucullaria), and Virginia Bluebells (Mertensia virginica). These plants depend on the brief window of spring sunlight in deciduous forests, which is why they are found in woodland settings and shade gardens rather than sunny prairies.
What is the role of fire in prairie ecosystems?
Fire is essential to prairie health. For thousands of years, lightning strikes and fires set by Indigenous peoples swept across the prairie every few years, killing tree seedlings, recycling nutrients back into the soil, and stimulating new growth from the deep root systems of prairie grasses and wildflowers. Without fire, woody plants gradually invade and shade out prairie species, converting prairie to woodland.
Today, land managers use prescribed burns (carefully planned and controlled fires) to maintain prairies and prairie restorations. Prescribed burns remove dead plant material, suppress invasive species, warm the soil to encourage warm-season grass growth, and release nutrients. Many native prairie plants have evolved to not only survive fire but to thrive after it.
How do native plants support pollinators?
Native plants and pollinators have co-evolved over thousands of years, developing specialized relationships. Minnesota is home to over 400 native bee species, along with butterflies, moths, hoverflies, beetles, and hummingbirds that all depend on native flowers for nectar and pollen. Many pollinators can only use specific native plant species.
The most famous example is the Monarch butterfly, which depends exclusively on milkweed species (Asclepias spp.) as host plants for its caterpillars. Without milkweed, monarchs cannot reproduce. Similarly, many native bee species have evolved to match the flower shapes, bloom timing, and pollen chemistry of specific native plants. A diverse native garden that blooms from spring through fall provides the continuous food supply that pollinators need to survive.
What are the forest layers and why do they matter for plant selection?
A healthy forest has distinct vertical layers, each supporting different plant species and wildlife. The canopy layer consists of the tallest trees (oaks, maples, pines) that form the forest ceiling. The understory layer includes smaller trees and tall shrubs growing beneath the canopy. The ground cover layer is made up of wildflowers, ferns, mosses, and low-growing plants on the forest floor.
Understanding forest layers matters because each layer receives different amounts of sunlight. Canopy trees need full sun. Understory plants are adapted to partial shade. Ground cover species, including spring ephemerals, thrive in deep shade or use the brief window of spring sunlight before the canopy fills in. When designing a woodland garden, you want to include plants from multiple layers to create a natural, self-sustaining plant community.
What native plants grow well in wet or shoreline areas?
Minnesota's wetlands and shorelines support a rich community of native plants adapted to saturated soils and seasonal flooding. Excellent choices for wet areas include Blue Flag Iris (Iris versicolor), Cardinal Flower (Lobelia cardinalis), Joe-Pye Weed (Eutrochium maculatum), native cattails, and various sedge species. For shoreline stabilization, native shrubs like Red-Osier Dogwood and Buttonbush work well.
These plants serve critical ecological functions. Their roots stabilize shorelines and prevent erosion. Their dense growth filters pollutants from runoff before it enters lakes and streams. They also provide habitat for frogs, turtles, nesting waterfowl, and aquatic insects. If you live near a lake or stream, planting a buffer of native shoreline plants is one of the most effective ways to protect water quality.
What is biodiversity and why does it matter in native plantings?
Biodiversity refers to the variety of life in a given area, including the number and types of species, the genetic variation within those species, and the diversity of ecosystems they form. In a native planting, biodiversity is essential because diverse plant communities are more resilient, support more wildlife, and provide more ecosystem services than monocultures.
A prairie planting with 30 or more species will outperform one with 5 species in almost every way. Greater species diversity means longer bloom seasons for pollinators, better resistance to drought and disease, more complete ground coverage to suppress weeds, and a wider range of root depths that improve soil structure and water filtration. Nature does not plant in rows of one species, and neither should you.
What is the significance of milkweed for Monarch butterflies?
Milkweed (Asclepias spp.) is the only plant genus that Monarch butterfly caterpillars can eat. Female Monarchs lay their eggs exclusively on milkweed leaves, and the caterpillars feed on milkweed foliage as they grow. Without milkweed, Monarchs cannot complete their life cycle.
Minnesota is part of the Monarch's central flyway migration route, making our state critical habitat for this iconic species. Common Milkweed (Asclepias syriaca), Butterfly Milkweed (Asclepias tuberosa), and Swamp Milkweed (Asclepias incarnata) are all native to Minnesota and suitable for home gardens. Planting even a small patch of milkweed contributes to Monarch conservation. The dramatic decline in milkweed across the Midwest due to agricultural herbicide use is considered a primary cause of the Monarch population's steep decline.
What are mycorrhizal networks and why are they important?
Mycorrhizal networks are underground fungal partnerships that connect plant roots to each other and to the surrounding soil. The fungi extend far beyond the root zone of individual plants, effectively creating a vast underground web that moves water, nutrients, and even chemical signals between plants. In exchange for these services, the fungi receive sugars produced by the plants through photosynthesis.
These networks are especially important in prairie and forest ecosystems. They help young seedlings establish by linking them to the resources of mature plants. They increase the effective root area of every connected plant by orders of magnitude. When you install native plants, you are also building these fungal networks, which is why native plantings become increasingly healthy and resilient over time. Using locally sourced plants and avoiding fungicides helps preserve these vital underground communities.
What is a riparian buffer and why should shoreline property owners plant one?
A riparian buffer is a strip of native vegetation along a lake, river, or stream bank. It serves as a transition zone between the water body and the surrounding land. Riparian buffers typically include native grasses, wildflowers, shrubs, and trees selected for their ability to tolerate wet soils and periodic flooding.
Buffers protect water quality by filtering sediment, nutrients (especially phosphorus and nitrogen), and pollutants from runoff before they reach the water. They stabilize shorelines, reduce erosion, provide shade that keeps water cool for fish, and create critical habitat for wildlife. Minnesota's buffer law requires vegetative buffers along public waters and public drainage ditches. Even where not legally required, planting a buffer is one of the most impactful conservation actions a lakefront or riverside property owner can take.
How do native plants help manage stormwater?
Native plants manage stormwater through their deep, extensive root systems and the porous soil structure those roots create. A conventional lawn has roots that extend only 2 to 4 inches deep and compacted soil that sheds water like pavement. Native prairie plants send roots 5 to 15 feet deep, creating channels that allow rainwater to infiltrate the soil rather than running off the surface.
This infiltration reduces the volume and speed of stormwater entering storm drains, streams, and lakes. It also recharges groundwater supplies. Rain gardens, bioswales, and native shoreline buffers are practical applications of this principle. A single rain garden planted with native species can capture and filter thousands of gallons of stormwater per year, reducing flooding and protecting downstream water quality.
What is plant succession and how does it apply to native landscapes?
Plant succession is the natural process by which plant communities change over time. In Minnesota, an abandoned farm field will first be colonized by annual weeds, then perennial grasses and wildflowers, then shrubs and small trees, and eventually mature forest. Each stage creates conditions that favor the next stage of plants.
Understanding succession helps you plan and manage native landscapes. A prairie restoration, for example, requires periodic fire or mowing to prevent succession from converting it to woodland. A woodland restoration might use early-stage, sun-loving species as nurse plants to create shade for later-stage, shade-tolerant species. Working with succession rather than against it is a core principle of ecological restoration.
What is a pollinator garden and how is it different from a regular flower garden?
A pollinator garden is specifically designed to provide food (nectar and pollen), shelter, and nesting habitat for bees, butterflies, moths, and other pollinators throughout the growing season. Unlike a conventional flower garden that prioritizes visual appeal, a pollinator garden prioritizes ecological function.
Key differences include selecting plants for their nectar and pollen value rather than just appearance, ensuring continuous bloom from early spring through late fall so pollinators always have food, planting in clusters of the same species so pollinators can forage efficiently, including host plants for caterpillars (like milkweed for Monarchs), leaving some bare ground for ground-nesting bees, and leaving dead stems standing through winter as overwintering habitat for native bees. Of course, a well-designed pollinator garden is also beautiful.
What is the difference between a nativar and a wild-type native plant?
A nativar (short for "native cultivar") is a cultivated variety of a native plant that has been bred or selected for specific ornamental traits such as compact size, unusual flower color, or double blooms. Examples include 'Magnus' Purple Coneflower or 'The Blues' Little Bluestem. A wild-type native plant is the unselected, genetically diverse form that occurs naturally in the wild.
While nativars look attractive in gardens, some may offer reduced ecological value compared to wild types. Breeding for doubled flowers can reduce nectar and pollen availability. Selecting for unusual colors may make flowers less recognizable to pollinators. Compact growth forms may provide less habitat structure. When your primary goal is supporting wildlife and pollinators, wild-type native plants from local seed sources are generally the best choice.
Plant Identification and Selection
How do I identify an unknown plant I find in the field?
Start by observing the plant's key features: leaf shape and arrangement on the stem, flower structure and color, overall growth habit (height, form), and where it is growing (sun or shade, wet or dry). These features narrow the possibilities significantly. A simple field guide organized by flower color or leaf shape is a great starting tool.
You can also use plant identification apps on your smartphone, which analyze a photo and suggest matches. However, always verify app suggestions against a reliable field guide or expert opinion, as apps can make mistakes, especially with similar-looking species. The University of Minnesota Extension and MN DNR websites offer online identification resources specific to Minnesota plants.
How do I choose the right native plants for my yard?
Plant selection starts with understanding your site conditions. Observe how much sunlight each area receives (full sun, partial shade, or full shade), test your soil type (sandy, clay, or loam), note whether the soil tends to be wet, medium (mesic), or dry, and check your USDA hardiness zone. Then select species that match those conditions.
For example, a sunny, dry site with sandy soil would be ideal for prairie species like Little Bluestem, Prairie Dropseed, and Butterfly Milkweed. A shady, moist site under mature trees would suit woodland species like Wild Ginger, Solomon's Seal, and native ferns. Matching the plant to the site is the single most important factor in gardening success, and it is even more important than how much care you provide after planting.
What are the best native plants for beginners in Minnesota?
Several Minnesota native plants are particularly easy to grow and rewarding for beginners. For sunny areas, try Purple Coneflower (Echinacea purpurea), Black-Eyed Susan (Rudbeckia hirta), Wild Bergamot (Monarda fistulosa), and Little Bluestem (Schizachyrium scoparium). For shady areas, Wild Geranium, Solomon's Seal, and native ferns are reliable and attractive.
These species are widely available at Minnesota native plant nurseries, establish quickly, tolerate a range of soil types, and provide excellent wildlife value. Start with a mix of six to ten species that bloom at different times to ensure continuous interest from spring through fall. As you gain experience, you can add more specialized species suited to your specific site conditions.
How do I tell the difference between native sedges and invasive grasses?
Sedges and grasses look similar at first glance, but they have distinct physical features. The classic mnemonic is "sedges have edges" -- sedge stems are triangular in cross-section, while grass stems are round and hollow. Roll a stem between your fingers and you will feel the three-sided shape of a sedge.
Other differences include leaf arrangement (sedges have leaves in three ranks; grasses in two), flower structure (sedges produce clustered spikelets; grasses produce florets in different arrangements), and habitat preference (many sedges prefer wetter conditions than grasses). Native sedges like Pennsylvania Sedge are valuable ground covers for shade gardens and are not invasive. Invasive grasses like Reed Canary Grass tend to form dense, aggressive monocultures that crowd out all other plants.
What should I look for when buying native plants from a nursery?
When purchasing native plants, look for nurseries that specialize in native species and can tell you where their seed was sourced. Ideally, choose plants grown from seed collected within your region of Minnesota (called local ecotypes), as these plants carry genetic adaptations to your specific climate and soil conditions.
Avoid big-box stores that may label plants "native" without specifying origin, or that sell nativars bred for ornamental traits at the expense of ecological value. Check that plants are healthy, with good root development and no signs of disease. Ask whether plants were grown without neonicotinoid pesticides, as these chemicals harm pollinators. Minnesota has several excellent native plant nurseries, including Prairie Moon Nursery, Shooting Star Native Seeds, and Minnesota Native Landscapes, among others.
How do I use a seasonal bloom sequence to plan my garden?
A seasonal bloom sequence ensures that something is flowering in your garden from early spring through late fall, providing continuous food for pollinators. Start by listing native plants that bloom in each season: early spring (April to May), late spring (May to June), early summer (June to July), midsummer (July to August), late summer (August to September), and fall (September to October).
For example, a sunny Minnesota garden might include Pasque Flower for early spring, Wild Lupine and Golden Alexander for late spring, Purple Coneflower and Wild Bergamot for summer, Blazing Star and Joe-Pye Weed for late summer, and asters and goldenrods for fall. Aim for at least three species blooming in each season. The Bloom Calendar MicroSim in this textbook can help you visualize and plan your sequence.
What does "local ecotype" mean and why does it matter?
A local ecotype is a population of a plant species that has adapted to the specific conditions of a particular geographic area over many generations. A Purple Coneflower grown from seed collected in southeastern Minnesota may differ genetically from one grown from seed collected in Montana, even though they are the same species. The Minnesota population carries adaptations to Minnesota's specific soils, climate, pests, and growing season.
Planting local ecotypes matters because these plants are more likely to thrive in your conditions, and they preserve the genetic diversity that helps species adapt to changing environments over time. When you buy native plants, ask your nursery about seed provenance, the geographic origin of the seed used to grow the plants.
How can I identify native plants in winter when there are no leaves or flowers?
Winter identification relies on features like bark texture and color, branching pattern, overall tree or shrub silhouette, remaining seed heads and fruits, and bud shape and arrangement. Many native plants have distinctive winter characteristics. For example, the peeling bark of River Birch, the persistent seed heads of Purple Coneflower, and the coppery dried foliage of Little Bluestem are all recognizable in winter.
Leaving seed heads and dried stems standing through winter is both a good identification practice and an ecological one, as they provide food for birds and overwintering habitat for native bees and other beneficial insects. Field guides with winter identification features are available, and practice outings with local naturalist groups can build your winter ID skills quickly.
How do I assess my soil type for native plant selection?
A simple field test is the ribbon test: take a handful of moist soil and squeeze it in your fist. Sandy soil feels gritty, falls apart easily, and does not form a ribbon when pressed between your thumb and forefinger. Clay soil feels smooth and sticky, holds its shape, and forms a long, flexible ribbon. Loam, the ideal middle ground, feels slightly gritty and slightly smooth and forms a short ribbon that breaks apart.
You can also observe how water behaves on your site. Sandy soil drains very quickly and dries out fast. Clay soil holds water, sometimes forming puddles that last for hours or days. For a more detailed analysis, you can submit a soil sample to the University of Minnesota Extension soil testing lab, which will report soil type, pH, and nutrient levels.
What is the "right plant, right place" principle?
"Right plant, right place" is the foundational principle of native plant gardening. It means selecting plants based on the conditions your site actually offers rather than trying to change the site to suit plants you want to grow. If you have a shady, moist corner, plant shade-loving woodland species there. If you have a hot, dry slope, plant drought-tolerant prairie species.
This approach works because native plants evolved to thrive in specific conditions. A Purple Coneflower planted in deep shade will struggle, become leggy, and produce few flowers. The same plant in full sun will thrive with minimal care. Matching plants to their preferred conditions reduces maintenance, eliminates the need for amendments and irrigation, and produces healthier, more attractive plantings.
Can I use a plant identification app to identify native plants?
Yes, plant identification apps can be a helpful starting point, but they have limitations. Apps work best when you provide a clear, well-lit photo of the plant's most distinctive features (flowers, leaves, or fruits). They are less reliable for grasses, sedges, and plants that are not in bloom. Apps may also misidentify similar-looking species, especially native versus invasive look-alikes.
Always verify app suggestions against a reliable field guide, a university extension resource, or an experienced botanist. In Minnesota, the MN DNR website and the University of Minnesota Extension have searchable databases and identification guides tailored to our state's flora. Local plant walks and workshops offered by organizations like the Minnesota Native Plant Society are excellent ways to build identification skills.
Invasive Species
What are the most problematic invasive species in Minnesota?
Minnesota's most damaging invasive plants include Common Buckthorn (Rhamnus cathartica), Garlic Mustard (Alliaria petiolata), Spotted Knapweed (Centaurea stoebe), Wild Parsnip (Pastinaca sativa), Purple Loosestrife (Lythrum salicaria), Reed Canary Grass (Phalaris arundinacea), Leafy Spurge (Euphorbia esula), and Japanese Barberry (Berberis thunbergii). The Emerald Ash Borer, an invasive insect, has also devastated Minnesota's ash trees.
Each of these species causes distinct types of harm. Buckthorn forms dense thickets that shade out native woodland plants. Garlic Mustard produces chemicals that disrupt soil fungi needed by native plants. Purple Loosestrife invades wetlands and displaces native cattails and sedges. Collectively, invasive species cost Minnesota hundreds of millions of dollars per year in management and lost ecological value.
How do I identify Common Buckthorn?
Common Buckthorn (Rhamnus cathartica) is a tall shrub or small tree, typically 10 to 25 feet tall. Key identification features include oval leaves with finely toothed edges and 3 to 5 pairs of curved veins that follow the leaf margin. Leaves are arranged in a sub-opposite pattern on the stem. Look for a small, sharp thorn at the tip of many twigs. The bark is gray to brown, and scraping it reveals yellow-orange inner bark.
One of the most reliable field clues is timing: buckthorn leaves stay green well into late fall, long after native trees and shrubs have dropped theirs. In late summer and fall, buckthorn produces clusters of small, round black berries, each containing 3 to 4 seeds. A single tree can produce thousands of berries that birds spread across miles.
Why is buckthorn so hard to get rid of?
Buckthorn is exceptionally difficult to eradicate for several reasons. A single mature tree produces thousands of seeds per year. Birds eat the berries and spread seeds across long distances. Seeds remain viable in the soil for years, creating a persistent seed bank that continues to germinate long after adult trees are removed.
Buckthorn also resprouts vigorously from the stump and root crown when cut. Simply cutting a buckthorn tree without treating the stump will often result in multiple new stems emerging. Effective removal requires either treating cut stumps with herbicide or pulling entire small plants including the root. Even with proper treatment, the seed bank means that follow-up monitoring and removal of new seedlings must continue for five to ten years or more.
What is the best way to remove Garlic Mustard?
Garlic Mustard (Alliaria petiolata) is a biennial plant, meaning it takes two years to complete its life cycle. The most effective manual removal method is hand-pulling second-year plants in spring before they set seed, ideally when the soil is moist so you can extract the entire root. Pull carefully and bag the plants, as pulled plants with flowers can still produce viable seeds.
Because garlic mustard has a seed bank that can persist in the soil for several years, you must return to the site every spring for at least five consecutive years to pull new plants before they flower. Consistency is more important than perfection. If you pull 90 percent of the plants each year for five years, the population will crash. One missed year, however, can undo multiple years of effort.
What is the difference between an aggressive native plant and an invasive species?
This is an important distinction. An aggressive native plant is a species that spreads readily but is part of the local ecosystem and supports native wildlife. Goldenrod, for example, spreads vigorously but provides critical fall nectar for pollinators and does not displace other native species from healthy plant communities. An invasive species is a non-native plant that spreads aggressively and causes ecological harm by displacing natives, altering soil chemistry, or disrupting food webs.
The key difference is origin and ecological impact. Aggressive natives fill a role in the ecosystem and coexist with other native species. Invasive exotics have no natural controls in Minnesota, grow unchecked, and degrade the ecosystems they invade. You may need to manage aggressive natives in a small garden, but they are not ecologically harmful the way true invasive species are.
What should I do if I find an invasive species on my property?
First, confirm the identification. Use the resources in Chapter 8 or contact your county's Soil and Water Conservation District (SWCD) for help identifying the species. Once confirmed, assess the size of the infestation. A few plants can often be managed with hand-pulling. Larger infestations may require a more comprehensive removal plan combining manual, mechanical, and possibly chemical methods.
Report the sighting to the MN DNR using their online reporting tool, especially if the species is new to your area. Early detection of new infestations is critical because small populations are far easier and cheaper to control than established ones. Your county SWCD may also offer technical assistance and sometimes cost-share funding for invasive species removal.
How do I report an invasive species sighting in Minnesota?
The MN DNR operates an online reporting system for invasive species sightings. You can submit reports through the MN DNR website or by contacting your local DNR office. Include the location (as precise as possible, with GPS coordinates if available), the species you believe you found, photos showing key identification features, the estimated size of the infestation, and the date of your observation.
You can also report sightings to your county Soil and Water Conservation District or to the University of Minnesota Extension. For aquatic invasive species, Minnesota has a specific reporting system and a law requiring boaters to take precautions. Timely reporting helps agencies respond to new infestations before they become unmanageable.
Why is Wild Parsnip dangerous and how do I recognize it?
Wild Parsnip (Pastinaca sativa) is both an ecological invader and a health hazard. Its sap contains chemicals called furanocoumarins that, when they contact skin and are then exposed to sunlight, cause severe burns and blisters known as phytophotodermatitis. These burns can leave scars that persist for months or years.
Wild Parsnip is a biennial or short-lived perennial that grows 2 to 5 feet tall with yellow, flat-topped flower clusters (umbels) that resemble Queen Anne's Lace. It has grooved stems, compound leaves with toothed leaflets, and a thick taproot. It is commonly found along roadsides, ditches, and field edges across Minnesota. If you need to remove Wild Parsnip, wear long sleeves, long pants, gloves, and eye protection, and work on overcast days when UV exposure is lower.
What is allelopathy and how do invasive plants use it?
Allelopathy is the release of chemical compounds by one plant that inhibit the growth, germination, or survival of neighboring plants. Several invasive species in Minnesota use allelopathy as a competitive weapon. Garlic Mustard, for example, produces compounds that disrupt the mycorrhizal fungi that native plants depend on for nutrient uptake. This gives Garlic Mustard a significant advantage because it does not depend on these fungi itself.
Buckthorn also alters soil chemistry in ways that favor its own seedlings over native species. The result is that simply removing an invasive species may not be enough to restore a site. The soil conditions it created may persist for years, making it necessary to actively replant native species and rebuild soil communities as part of the restoration process.
What is integrated pest management for invasive species?
Integrated pest management (IPM) is an approach that combines multiple control methods rather than relying on a single technique. For invasive species, IPM typically involves using manual removal (hand-pulling, digging), mechanical removal (cutting, mowing), chemical control (targeted herbicide application), and biological control (introducing natural enemies from the invasive species' home range) in a coordinated plan.
The specific combination depends on the species, the site, the size of the infestation, and available resources. For example, a buckthorn removal plan might involve cutting large trees with a chainsaw, treating stumps with herbicide to prevent resprouting, hand-pulling seedlings over several years, and planting native species to fill in the gaps and compete with new buckthorn seedlings. No single method works alone, and multi-year follow-up is always required.
How long does it take to control an invasive species infestation?
Effective invasive species management is a multi-year commitment, not a one-time event. For most species, plan on a minimum of three to five years of active management, with ongoing monitoring after that. Buckthorn infestations, because of the persistent seed bank, may require five to ten years of follow-up to prevent recolonization from dormant seeds in the soil.
The first year of removal typically produces the most dramatic visible results, but the real work happens in the follow-up years when you must return repeatedly to remove new seedlings before they mature and produce seeds. Skipping even one year of follow-up can allow the seed bank to replenish and undo years of previous effort. Setting realistic expectations and planning for multi-year follow-up from the start is essential.
What are the ecological effects of European earthworms in Minnesota?
This one surprises many people. Minnesota's northern forests evolved without earthworms, which were eliminated by the glaciers that covered the state during the last ice age. The thick, spongy leaf litter (duff layer) on the forest floor in these forests developed in the absence of worms and is essential for the survival of native forest wildflowers, fern species, and tree seedlings.
European earthworms, introduced through fishing bait, compost, and soil transport, consume this leaf litter rapidly. Within a few years of earthworm invasion, the forest floor duff can be entirely consumed, exposing bare soil. Native wildflowers like Trillium, Hepatica, and native ferns lose their protective mulch layer and often decline or disappear. The compacted, nutrient-altered soil that results favors invasive species over natives.
Garden Design and Maintenance
How do I design a native plant garden from scratch?
Start with a thorough site assessment. Walk your property at different times of day and note sun exposure, soil type, moisture levels, and any microclimates. Sketch a rough map of your yard showing these conditions. Then select plants that match each area's conditions, aiming for a mix of grasses, wildflowers, and possibly shrubs that bloom across the seasons.
Arrange plants in natural-looking clusters rather than single rows. Place taller species toward the back or center and shorter ones along edges. Include at least three plants of each species to create visual mass and make it easier for pollinators to forage. Plan for the mature size of each plant, not its size at planting. Leave space for plants to spread. Start with a manageable area (even 50 to 100 square feet) and expand in subsequent years as you learn what works on your site.
What is site preparation and why is it so important?
Site preparation is the process of removing existing vegetation and reducing the weed seed bank before planting native species. It is the single most important factor in whether a native planting succeeds or fails. Skipping or rushing site prep is the number one reason native plantings disappoint.
Methods include smothering with cardboard and mulch (leave for one full growing season), solarization with clear plastic sheeting in summer, sod removal, repeated mowing and tilling to exhaust the weed seed bank, or herbicide application. Plan on at least one full growing season for site preparation. For sites with aggressive perennial weeds like quackgrass or Canada thistle, plan on two seasons. The time you invest in site prep saves you months of weeding after planting.
How do I maintain a native planting in the first year?
The first year is critical and requires the most active management. Water new plantings during dry spells for the first growing season, especially plugs and container plants. Weed regularly, at least every two to three weeks, focusing on removing aggressive weeds before they set seed. Learn to distinguish your planted native seedlings from weeds, as many natives look like grass in their first year.
Mow your native planting to a height of 4 to 6 inches two or three times during the first growing season. This suppresses weeds while allowing native seedlings to grow. Do not fertilize, as fertilizer tends to benefit weeds more than the slow-growing natives. Be patient -- most native plants focus on root development in their first year and will look sparse above ground. This is normal and expected.
What maintenance does a native garden need after it is established?
Once established (typically after two to three years), native gardens require far less maintenance than conventional landscapes. Annual tasks include cutting back or mowing dead growth in late winter or early spring (leave it standing through winter for wildlife habitat), removing any invasive species that appear, and hand-pulling weeds that emerge in gaps.
If your native planting includes prairie species, a prescribed burn every three to five years is the ideal maintenance tool. Burning removes accumulated dead material, suppresses woody invaders, and stimulates vigorous new growth. If burning is not feasible, mowing to 4 to 6 inches in early spring achieves some of the same benefits. Over time, as native plants fill in, maintenance needs continue to decrease.
Can I replace my entire lawn with native plants?
Yes, many Minnesota homeowners have successfully converted all or part of their lawns to native plantings. Options range from a native seed lawn using short grasses and sedges like Pennsylvania Sedge or Prairie Dropseed to a full-scale prairie planting with tall grasses and wildflowers to a woodland garden under existing trees.
Before converting, check your city's ordinances. Some municipalities have height restrictions or weed ordinances that may require you to maintain a mowed border or obtain a variance. Many Minnesota cities, including Minneapolis and Saint Paul, have adopted native plant-friendly ordinances that specifically allow native plantings. Talking to your neighbors and keeping neat, visible edges around your planting helps build community acceptance.
How do I design a shade garden with native plants?
Shade gardens are ideal for native woodland plants that evolved under the canopy of Minnesota's forests. Begin by assessing the type of shade (dappled shade under deciduous trees is different from deep shade under evergreens) and the soil moisture level. Most woodland natives prefer moist, well-drained soils rich in organic matter.
Excellent native shade garden plants include Wild Ginger (Asarum canadense) as a ground cover, Solomon's Seal (Polygonatum biflorum) for mid-height structure, Jack-in-the-Pulpit (Arisaema triphyllum) for unique flowers, native ferns like Maidenhair Fern for texture, and spring ephemerals like Bloodroot and Trillium for early color. Layer these plants by height, just as they grow in natural woodlands, with ground covers at the base, mid-height perennials in the middle, and shrubs or small trees above.
What are the best native plants for curb appeal?
Native plants can be just as visually stunning as conventional ornamentals. For eye-catching front yard plantings, consider Little Bluestem (Schizachyrium scoparium) for its striking blue-green summer foliage and coppery fall color, Purple Coneflower for its large, showy blooms, and Blazing Star (Liatris spp.) for its dramatic purple flower spikes. Prairie Dropseed forms tidy mounds with fragrant fall blooms.
The key to curb appeal with natives is design, not species selection alone. Use clear, intentional edges between your planting and adjacent lawn or sidewalks. Group plants in masses of three to five rather than scattering individual plants. Include some evergreen or semi-evergreen elements for winter interest. A well-designed native planting looks intentional and cared for, which is what neighbors and passersby respond to.
What native plants provide winter interest in the garden?
Many native plants offer visual interest well into winter. Ornamental grasses like Little Bluestem, Big Bluestem, and Indian Grass hold their copper and golden foliage through fall and into winter. The seed heads of Purple Coneflower, Black-Eyed Susan, and Blazing Star provide texture and food for birds. Native shrubs like Red-Osier Dogwood have bright red stems that stand out against snow.
Leaving dead stems and seed heads standing through winter is both aesthetically pleasing and ecologically important. Many native bees overwinter in hollow stems. Birds like goldfinches and juncos feed on seed heads. Snow catches on standing stems, creating insulating microclimates. Cut back dead material in late winter or early spring before new growth begins, or leave it if you plan a spring prescribed burn.
How do I handle weeds in a native planting?
Weed management is the biggest challenge in the first two to three years. Hand-pulling is effective for small areas. Pull weeds when the soil is moist so you can extract the entire root, especially for perennials like thistle and dandelion. Focus on removing weeds before they set seed to prevent the population from growing.
For larger areas, selective mowing (cutting above the height of your native seedlings) suppresses annual weeds without harming the natives. Mulching with weed-free straw or wood chips around planted plugs can also help, but avoid deep mulch over seeded areas. Once native plants fill in, usually by the third growing season, they form a dense canopy that shades out most weeds naturally. Patience during those first few years pays off dramatically.
How do I plan a garden for year-round visual interest?
Year-round interest requires thinking beyond summer bloom season. Plan for spring flowers (ephemerals and early wildflowers), summer blooms (the peak of prairie wildflower season), fall color (asters, goldenrods, grass color change), and winter structure (seed heads, dried grasses, colored stems, evergreen elements).
A simple framework: choose three to five species for each season. In spring, use Pasque Flower, Virginia Bluebells, and Wild Phlox. In summer, use Purple Coneflower, Wild Bergamot, and Blazing Star. In fall, use New England Aster, Stiff Goldenrod, and Little Bluestem (for foliage color). For winter, rely on the standing seed heads of summer and fall bloomers plus native shrubs like Red-Osier Dogwood. Add evergreen native ground covers like Bearberry where appropriate.
Where can I find native plants and seeds in Minnesota?
Minnesota has several excellent native plant nurseries and seed sources. Prairie Moon Nursery in Winona is one of the largest native plant nurseries in the region. Shooting Star Native Seeds in Spring Grove specializes in local ecotype seeds. Minnesota Native Landscapes in Otsego offers native seed mixes and consultation services. Other reputable sources include Out Back Nursery and Landscape Alternatives.
Many county Soil and Water Conservation Districts also hold annual native plant sales, often at lower prices. The Minnesota Native Plant Society maintains a list of recommended native plant sources. When purchasing, ask about seed provenance (where the seed was collected) and whether plants were grown without neonicotinoid pesticides. Avoid purchasing "native" plants from big-box stores unless you can verify their origin.
Advanced Topics
What is ecological restoration and how does it differ from gardening?
Ecological restoration is the science and practice of repairing damaged, degraded, or destroyed ecosystems. While a garden is designed primarily for human enjoyment, a restoration project aims to re-establish the ecological processes -- nutrient cycling, pollination, natural disturbance, seed dispersal -- that allow a plant community to sustain itself over time.
Restoration draws on botany, soil science, hydrology, wildlife biology, and traditional ecological knowledge. Key principles include prioritizing ecosystem function over appearance, using locally sourced seed to preserve genetic adaptations, incorporating natural disturbance like fire, and planning for years or decades of development. A restoration project's success is measured not by how pretty it looks, but by whether ecological processes are functioning independently.
What role do Indigenous land management practices play in Minnesota's ecosystems?
Indigenous peoples, including the Dakota and Ojibwe, have managed Minnesota's landscapes for thousands of years. The most significant practice is intentional burning: setting fires to encourage new grass growth, attract bison, improve travel routes, and maintain open prairie and savanna landscapes. The tallgrass prairie that European settlers encountered was not untouched wilderness but a landscape actively shaped by Indigenous stewardship.
Today, the field of restoration ecology increasingly recognizes the value of Indigenous land management knowledge. Practices like controlled burning, which modern land managers now use as prescribed fire, were developed and refined by Indigenous communities over millennia. Engaging with this knowledge requires humility and respect for Indigenous intellectual sovereignty. Not all traditional knowledge is meant to be shared publicly, and learning should happen through relationships with Indigenous-led programs and organizations.
What is systems thinking and how does it apply to native plant conservation?
Systems thinking is a way of understanding the world by examining the relationships between parts rather than studying each part in isolation. Instead of asking "What does this plant do?" a systems thinker asks "How does this plant interact with everything around it, and what happens when it is removed?"
Applied to native plant conservation, systems thinking reveals why simple interventions often produce unexpected results. Removing buckthorn from a woodland, for example, suddenly allows more sunlight to reach the forest floor, which may initially benefit both native wildflowers and invasive species. Without follow-up planting and monitoring, the invasive species may fill in faster than the natives, resulting in a different invasion replacing the first. Understanding feedback loops, trophic cascades, and unintended consequences helps land managers design more effective restoration strategies.
How do I evaluate claims about "native" or "pollinator-friendly" products?
Marketing language around native plants and pollinator conservation is often misleading. A plant labeled "pollinator-friendly" may have been treated with neonicotinoid pesticides that harm the very pollinators it is supposed to support. A seed mix labeled "native wildflower" may contain species native to other regions of the country but not to Minnesota. "Eco-friendly" lawn products may offer no measurable ecological benefit.
To evaluate claims, apply these criteria: Look for specific species names rather than vague terms like "wildflower mix." Check seed provenance, asking where the seed was collected. Look for third-party certifications rather than self-applied labels. Be skeptical of products that promise dramatic results with minimal effort. Consult trusted sources like the University of Minnesota Extension, the MN DNR, and the Minnesota Native Plant Society for evidence-based recommendations.
What is a reference ecosystem and why is it used in restoration?
A reference ecosystem is a well-functioning natural community that serves as a model for restoration work. It represents the type of plant community you are trying to recreate or recover. For example, if you are restoring a tallgrass prairie, your reference ecosystem might be a nearby prairie remnant that retains high species diversity and intact soil communities.
Reference ecosystems guide species selection, planting density, expected succession patterns, and benchmarks for measuring restoration success. They also remind us that restoration is not about creating something new but about recovering something that was lost. However, reference ecosystems are guides, not rigid templates. Climate change, altered hydrology, and new invasive species mean that a restored ecosystem may never look exactly like the reference. Adaptive management, adjusting your approach based on monitoring results, is essential.
What is adaptive management and why is it important in ecological restoration?
Adaptive management is a structured, iterative approach to managing natural systems that incorporates monitoring, evaluation, and adjustment into every phase of the work. Instead of implementing a fixed plan and hoping for the best, adaptive management treats every management action as an experiment that generates information to improve future decisions.
In ecological restoration, adaptive management is essential because ecosystems are complex and unpredictable. A prairie seeding mix that works beautifully on one site may fail on a similar-looking site nearby because of differences in soil microbiology, seed bank composition, or moisture patterns that were not apparent during initial assessment. By monitoring results systematically and adjusting species, timing, or methods in response, restoration practitioners improve their outcomes over time.
What are feedback loops in ecology and why should I understand them?
A feedback loop occurs when the output of a process influences its own input, either amplifying or dampening the original change. In ecology, feedback loops drive many of the patterns we observe. A positive (reinforcing) feedback loop amplifies change: for example, when climate warming melts permafrost, releasing stored carbon that causes more warming. A negative (balancing) feedback loop dampens change: for example, when a predator population grows, reducing prey, which then reduces the predator population.
Understanding feedback loops helps you anticipate what will happen when you intervene in an ecosystem. Removing a dominant invasive species triggers cascading changes as other species respond to the new conditions. Planting native species creates reinforcing loops as plants attract pollinators, which improve seed set, which increases the next generation of plants. Thinking in terms of feedback loops helps you plan for these dynamics rather than being surprised by them.
How do I detect misinformation about native plants and invasive species?
Misinformation about native plants circulates widely on social media, product labels, and popular articles. Common myths include claims that all native plants are low-maintenance from day one (they require establishment care), that any plant labeled "native" is appropriate for your area (regional origin matters), or that a single application of herbicide will eliminate an invasive species permanently (multi-year follow-up is always needed).
To evaluate claims, use these strategies: Check whether the source has institutional backing (university, government agency, peer-reviewed journal). Look for specific evidence rather than anecdotes or testimonials. Be suspicious of products promising dramatic results with no effort. Cross-reference claims with trusted resources like the University of Minnesota Extension, the MN DNR, and published field guides. Recognize that social media algorithms often amplify dramatic or alarming claims regardless of accuracy.
What Minnesota agencies and organizations support native plant conservation?
Minnesota has an extensive network of agencies and organizations dedicated to native plant conservation. At the state level, the Minnesota Department of Natural Resources (MN DNR) manages natural areas and regulates invasive species. The Board of Water and Soil Resources (BWSR) oversees conservation programs and provides grants. At the county level, Soil and Water Conservation Districts (SWCDs) offer technical assistance, cost-share programs, and native plant sales.
Educational institutions include the University of Minnesota Extension, which provides research-based guidance, and the Minnesota Landscape Arboretum. Nonprofit organizations include the Minnesota Native Plant Society, The Nature Conservancy, Great River Greening, and the Prairie Enthusiasts. Many cities also run their own native plant programs, boulevard planting initiatives, and urban forestry efforts. This rich ecosystem of support means that no matter where you are in Minnesota, help is available.
What is ethnobotany and why is it relevant to native plant study?
Ethnobotany is the study of the relationships between people and plants, particularly how different cultures use plants for food, medicine, fiber, ceremony, and other purposes. In the context of Minnesota native plants, ethnobotany recognizes that the Dakota and Ojibwe peoples have held vast, sophisticated knowledge of these plants for thousands of years, long predating Western botanical science.
Studying ethnobotany is relevant because it provides a more complete understanding of native plants and their significance. It also highlights that Indigenous plant knowledge is a living tradition, not a historical curiosity. Engaging with this knowledge requires humility and respect for Indigenous intellectual sovereignty. Not all knowledge is meant to be shared publicly, and learning should happen through relationships with Indigenous-led programs.