Native Plants
What are native plants?
“A plant is considered native if it has occurred naturally in a particular region, ecosystem, or habitat without human introduction.”
—National Wildlife Federation
Native plants have co-evolved with the other plants, animals, fungi, and bacteria as well as the climate, light and soil conditions in a particular habitat and region, and thus play meaningful roles in keeping particular ecosystems stable.
Why are native plants important?
Ecosystem services
“Native plants are the necessary heart of healthy ecosystems. Plants power the food web for the rest of life on earth. Within this web, it is the balance of co-evolutionary relationships that allows millions of different species to all live closely together within a shared place. In a local ecosystem, only the plants that have evolved over an extended period of time with the other flora and fauna present can successfully feed the entire web and keep it stable.”
— Grow Native Massachusetts
Native plants provide important ecosystem functions and services. They support a diverse array of insects and other wildlife. Native plants are particularly valuable for specialist species. Over 90% of plant-eating animals are specialists. Specialists are the opposite of generalist species, in that they are adapted to require a particular environment, and usually a specific diet, which often is limited to very few foods. Often specialist species feed on certain native plants, due to a symbiotic relationship that has formed over thousands of years. Habitat diversity that includes native plants is critical to these species’ survival.
A classic example of a relationship between a specialist species and a native plant is with monarch butterflies and native milkweeds. Monarch caterpillars only feed on the foliage of milkweed plants. Through milkweed plant habitat protections and plantings, people can help sustain monarch populations.
Crop production
Native plant communities additionally provide ecological support to fruit and vegetable growers by increasing the number and diversity of beneficial insects and pollinators. Many native plant species are found to be especially productive in providing habitat for pollinators and for beneficial insects that suppress crop pests. Native plantings can be beautiful, but their benefits go far beyond aesthetics.
Beneficial insects include, but are not limited to, soldier beetles, predatory wasps, tachinid flies, and an assortment of bees. Providing habitat in close proximity to vegetable crop production can have an impact on aphids, Colorado potato beetles, and other pests through predation and parasitoidism.
Water management & Soil health
Plant communities have two equally important portions. The above-ground photosynthetic portion of the plant communities is the obvious one to most people. At the same time, the below ground system of roots is equally important to the community. Native plants typically have very deep root systems. These roots improve water infiltration in the soils in which they are planted. Thus, native plants assist in managing rainwater and stormwater runoff, and increase groundwater recharge. Native plant roots support symbiotic microorganisms and fungi, and feed life underground. They help break up compacted soils, increase soil organic matter, and boost overall soil health.
The structure of roots systems is a very important component of how this below ground community functions. As seen in the diagram below, herbaceous broadleaf forbs (wildflowers) tend to either have a prominent taproot with some side branches or a coarsely fibrous root system. In contrast, graminoids (including grasses and sedges) tend to have densely fibrous fine-textured roots that more thoroughly occupy the root zone.
Can I actually make an impact by planting a few natives?
YES! You absolutely have the ability to increase valuable habitat, even in a small amount of space. You can incorporate native plants into your landscaping and farmscaping. Depending on the size of the plants, and time of year they’re planted, you will likely see beneficial insects and pollinator insects visiting your flowering natives in a relatively short amount of time. You will be providing critical food and nest sources for specialist species (and generalist insects as well).
Especially in urban spaces, individuals’ landscaping choices have a significant impact on habitat diversity and stormwater runoff mitigation. Established native plants will also help sequester carbon dioxide, and contribute to lowered temperatures in urban areas. There are myriad benefits to adding natives to your yard, and you do not need to convert your entire space into a native prairie in order to enjoy many of these benefits.
How do I incorporate native plants into my garden, farm, and/or landscaping?
The SWCD created a guide document to provide a recommended species list and methodology for establishing a native planting on Indiana small farms and gardens. These species are found to be especially productive in providing habitat for pollinators and for beneficial insects that suppress crop pests.
This publication was funded through the Indiana State Department of Agriculture’s Clean Water Indiana grant program.
Access the full guide: Native Plantings for Beneficial Insects and Pollinators (pdf).
The information in the guide is outlined in the web materials below.
STEP 1: CHOOSE YOUR PLANTS
Determine where you want to incorporate native plants. Site conditions will guide the plants you choose. The Marion County SWCD has developed a native plant list to target beneficial insects and pollinators and includes plants that are suitable to be in close proximity to vegetable gardens.
With most native plantings, and especially if you are planting a large area, it is ideal to select 70%–80% forbs (wildflowers) and 20%–30% graminoids (grass and sedges). Choose a diversity of plants with different bloom periods to provide continuous flowering throughout the year.
Recommended Species List:
Stature: Short: <24″ Medium: 24 – 48″ Large: > 48”
O’C’ Spacing On-center spacing indicates the spacing between plants. When two plants with different spacing are adjacent, use the larger of the two between them.
Field Strip (FS) Plants suited for plantings in close proximity to crops, such as beds or strips within the growing area. These plants are non-flopping, cast little shade, and can tolerate full sun and hot conditions.
Field Border (FB) Plants suited for perimeter and pocket plantings.
Tough (T) Plants that show resiliency in poor soil and hot conditions.
STEP 2: FINALIZE YOUR PLANT LIST
Cross-reference the SWCD plant list with additional lists to better determine plant suitability on your farm, garden, or landscaping, such as moisture and sunlight requirements. A couple of guide documents we especially recommend:
- Purdue Extension’s ‘Recommended Indiana-native Plants for Attracting Pollinators’ contains a table with “wet, wet mesic, mesic, dry mesic, and dry as well as general associations with pollinating insects.
- Indiana Native Plant Society’s ‘Landscaping with Plants Native to Indiana’ categorizes native plants according to light and moisture requirements.
STEP 1: ELIMINATE EXISTING VEGETATION
Option A: Mechanical (lawns)
- Remove the top inch of sod with a sod-cutter or hand tools. The top inch contains the majority of weed seeds.
- Remove any remaining perennial taproots such as dandelions.
- Sheet mulch with newspaper and hardwood fines if planting by plug.
- Seed and straw if planting by seed.
Tilling sod is not recommended as rhizomatous grasses may regrow, especially if the soil is moist. Tilling stimulates germination of the annual weed seed bank.
Option B: Cover Crops, Sheet Mulching, and Occultation (lawns / garden)
- Utilize occultation or black silage tarps to eliminate vegetation.
- Sheet mulch with cardboard / newspaper and hardwood fines if planting by plug.
- Seed and straw if planting by seed.
STEP 2: INSTALL NATIVE PLANTS
Option A: Installation of native planting via plug (recommended)
Timing:
- April 10 through May is optimal time
- Early September can be a sweet spot – warm soil and potential for rain
- Frost heaving can be an issue if planted after September 21
Method:
- Create a hole the depth of the plug (auger / trowel)
- Plant with the top of the soil plug level with surrounding soil.
- Backfill and firm the soil around the plug. Water thoroughly to settle the soil around the plug.
- Apply 1-2 inches of an organic mulch such as leaf compost or finely shredded hardwood mulch. Mulching can be done before or after transplanting.
- Taper mulch down to nothing near stem of plant to prevent crown rot.
- If soil is dry, apply an inch of water per week for the first six weeks. Once established, water only during extremely dry periods. If plants are wilted in the early morning, additional water is needed.
Layout and Spacing:
- Utilize a chart for On-Center Spacing, which is the recommended spacing between plants. When two plants with different spacing are adjacent, use the larger of the two between them. A good resource to calculate plant spacing options is through the Midwest Ground Covers’ plant calculator.
- Common spacing is 12” for small plants, 18” for medium plants, and 24” for large plants.
- It can be helpful to lay out the plants ahead of planting.
- One recommendation is to group plants of the same species together.
- Interspersed grasses increase weed suppression.
Option B: Installation of native planting via seeds
(For larger blocks where plugs may be cost-prohibitive. Not recommended for in-field strips. Plan on 3 to 5 years for full establishment via seeds.)
Timing
- Seeds may be broadcast during the dormant season
- December 1 – February 28
- Or in the spring planting window
- April 1 – June 15
- Many native species require getting wet and freezing to crack open. Dormant seeding will help these species establish faster. Ideally, time seeding prior to a snow or when temperature fluctuations are going to cause the ground to freeze and thaw.
- If seeding in the spring, culti-packing rough soil before broadcasting the seed often prevents seed from being planted too deep.
Method:
- Order the appropriate quantity of seed from a reputable native seed provider. Plan on at least 40 – 60 seeds per square foot.
- Plant seed no deeper than the width of the seed.
- Mix the seed with a sterile potting mix or other dry inert material with a ratio of one part seed to 3 parts inert material.
- Divide the seed mix in half. Spread half the seed over the entire area. Then spread the remaining half over the entire area. This ensures not running out of seed before the entire area is covered.
- Lightly mulch the seeding with straw so approximately half of the soil is visible through the straw.
- Keep the seed bed moist for the first 8 weeks to ensure germination.
During the first couple of years, most prairie grasses and wildflowers may show limited above-ground growth. During this time, the plants spend a lot of energy growing deep, extensive roots systems.
SPRING
Monitor for and remove cool-season weeds such as assorted mustards, annual brome species (Bromus spp), sweet clover (Melilotus spp), and Canada thistle (Cirsium arvense). Renew mulch along the edges and any significant areas of bare soil. Shredded hardwood (2” or less) should be added every two years and composted leaves may be added annually as a soil conditioner.
SUMMER
Monitor for and remove warm-season weeds such as ragweeds (Ambrosia spp), pigweeds (Amaranthus spp), foxtail (Setaria spp), and other typical annuals. Also monitor for aggressive rhizomatous perennials such as Canada goldenrod (Solidago canadensis), Johnson grass (Sorgham halepense), and Smooth Brome (Bromus inermis).
FALL
Remove or treat unwanted woody plant recruitment. Remove any remaining annual weeds prior to seed dispersal. Autumn leaves can be chopped up with a lawnmower and spread in the planting areas.
WINTER
In late winter, cut the planting down to 4 inches in height and remove the prior year’s herbaceous growth.
Plugs establish quicker and thus are easier to control weeds. With plugs, one is able to layout species in specific locations.
- Wholesale minimums can be $600, and each plug is ~ $1.80
- Retail may have no minimum, and each plant (size varies) is ~ $4 to $10
- Native plugs can be found locally from various sources (typically during limited date spring and fall sales). Find a source through the Grow Indiana Natives website.
Seeds are cheaper. Plantings are often denser and growth is generally slower.
- Cost: Individual seed packets versus pre-made mixes
Plugs: Wholesale Example
Mulch: An Example
- 500 sq. ft.
- 0.62 x 5 = 3.1 Cubic Yards
- 3 Cubic Yards times $37.50/yard = $112.50
- Delivery estimate: $40 – $60
Sourcing: Tiffanys (AAA), McCarty’s, Greencycle
Top 10 Indiana Native Plants
Every native plant has its values. There are SO many to choose from, and it can be overwhelming to select which ones to plant.
Here are some of our favorites.
Wildflowers
Asters (New England, Short’s, Smooth Blue)
Bergamot
Black eyed susans (Sweet, Showy)
Blazing stars (Prairie, Meadow, Dense, Marsh)
Coneflowers (Purple, Pale Purple, Yellow)*
Goldenrods (Stiff, Riddell’s)
Mountain mints (Virginia, Narrow Leaf)
Milkweeds (Common, Whorled, Swamp, Butterflyweed)*
Nodding wild onion
Wild senna
* important to select varieties native to Indiana, not cultivars.
Don’t forget the graminoids (grasses)!
Grasses provide important food sources for insect larvae.
Big bluestem
Little bluestem
Prairie dropseed
Northern dropseed
Burr sedge and many other sedges
Resources & Links
- Marion County SWCD: “Native Plantings for Beneficial Insects and Pollinators”
- Marion County SWCD: “Insect-Management” info and resources
- Purdue Extension: “Recommended Indiana-Native Plants for Attracting Pollinators”
- Indiana Native Plant Society (INPS): “Landscaping with Plants Native to Indiana”
- Xerces Society: “Pollinator Plants Midwest Region”
- Xerces Society: “Checklist of Actions to Promote Pollinators in Yards, Gardens, and Parks”
- USDA Natural Resources Conservation Service: Plants database
- Missouri Botanical Garden: Plant Finder
- Grow Indiana Natives: native plant nurseries / sources
- Grow Indiana Natives: certify your native garden
- Plant calculator: determine spacing for a plug planting
- Hamilton County SWCD: Creating and Maintaining a Prairie
