Native Landscaping Manual

Chapter One - Seeding a Tall Grass Prairie

Order Chapter One - Seeding a Tall Grass Prairie in booklet form

Introduction

This reconstruction method is designed for early winter seeding in Missouri. It will take two to three years for most seedlings to flower and at least three years for plants to overcome initial weeds. Timing and patience are important to achieve success. With careful attention to maintenance during the first year or two, you can create a beautiful and low-maintenance restoration on a small budget. With yearly burning or mowing, your restoration will survive for generations to enjoy. This method is simple and has been used at Shaw Nature Reserve in Gray Summit, Missouri over many years.

The range of the original tallgrass prairie is shown in blue on the map above. While it dominated northern and western Missouri, it's range also extended throughout southeastern Missouri in patches between rocky glades, open woodlands, and forested river bottoms. In Missouri, about 4 percent of the original prairie exists today, mostly in the western part of the state. Prairie landscapes are being reconstructed on state and private lands throughout the mid-west. They are used to reduce mowing on small farms, highway right-of-ways, college and corporate campuses, and golf courses.

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Determine Goals

Before beginning prairie reconstruction you should evaluate your site and determine what you hope to achieve. Ask yourself why are you reconstructing the site and what goals do you have for it? The answers will help you decide on the site location, layout, size, and seed mixture, all of which are described below. There are four basic reasons to reconstruct a tallgrass prairie.

Maintenance: It is more common for home and larger land owners to reduce mowing by replacing turf with prairie plants that need mowing only once a year.

Beautification: Tallgrass prairies with a diversity of grasses and wildflowers bloom from April through November and attract a host of colorful birds, butterflies, and insects. This landscaping style is used by homeowners, large and small, and by cities for park beautification.

Education: A tallgrass prairie reconstruction is a good opportunity to teach local cultural and natural history, while providing opportunities to develop math, reading, writing, art and science skills.

Ecological Reconstruction: Prairie reconstruction provides needed habitat for wildlife. Over 95 % of the original tallgrass prairie is gone in Missouri, replaced by agriculture and urban development. A prairie reconstruction project with a diversity of native plants attracts a diversity of insects, birds, amphibians, and mammals and provide opportunities to observe nature up close.

Prairie Borders: Small backyard prairie landscape with prairie dropseed grass edge and split-rail fence, left. Corporate prairie landscape with buffalo grass edge, middle. Large front-yard prairie landscape with mowed fescue edge along driveway, right. Each have well-defined borders that create a gentle visual transition from walkway to taller prairie. Fencing also prevents prairie plants from flopping at the edges.

(See bottom of document for a list of public reconstructed prairies in Missouri.)

Site Evaluation

Map the area. Note existing structures, utilities, traffic use, slope, north-south aspect, soil type, vegetation, patterns of shade and light, soil moisture and drainage, erosion, size and shape of the site, and maps. This will help you to decide where to locate a prairie and may be useful in explaining the project to neighbors, city officials, or maintenance crews.

Survey Vegetation. A plant survey of the site and surrounding area may reveal clues to the plant community that existed and helps you decide what needs to be done first. For example, if native prairie grasses and forbs grow in a nearby fencerow or roadside, seeds of these plants could be collected and used in the project, or at least guide plant selection. You may find that the site is covered with shrubs, vines, or weedy vegetation. If possible, avoid areas that are infested with crown vetch, bird's foot trefoil, Johnson grass, and sericea lespadeza, they are very difficult to control.  This will help prioritize the reconstruction steps.

Research Land Use History.

Has the land recently been in row crop production? If so, has the herbicide Atrazine been used? Atrazine may prevent germination of prairie seeds up to a year after its application. Herbicide resistant row crops can be an advantage by keeping the field weed-free until seed sowing time in late November and early December. We recommend Roundup-Ready crops be used in the season immediately preceding prairie seeding.

Is the site suitable for a tallgrass prairie? Look for evidence that a prairie existed on the site. Is it a part of the oral tradition in your community? Do prairie plants exist in the area? If there are trees, the site may have been prairie anyway. Much of the tallgrass prairie south of the Missouri River has been replaced with forest over the past 200 years. If you have attractive specimen trees, consider seeding the site with savanna species. They are more tolerant of shade and drought. see the sample seed list below for savannas.

Create a Schedule. Before going any further, it is important to plan step-by-step in advance so each step is done in sequence. See sample schedule below.

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Tips for Species Selection

Diversity: The more diverse the plant life, the greater the diversity of wildlife that will come for food and shelter. A diversity of native plants also tends to ensure blooming from early spring through early winter. Typical commercial prairie seed mixes include about 25 species.

Soil moisture determines proper species selection.

• Dry:  Well-drained soil, on south or west-facing slopes with shallow or rocky soils. Soil surface dries quickly.
• Mesic:  Medium soil moisture, often gently sloped land. Soil surface retains moisture several days.
• Wet:  Poorly drained soil, usually in flat, low ground. Soil surface remains inundated with water after rain.

The species selection guide at bottom of page lists dry, mesic, and wet species.

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Tips for Site Preparation

Removing existing vegetation is critical. This process is more important than any other step, so be sure it is done thoroughly before seeding prairie. It may take more than one season to control difficult weed species.

If starting with a turf lawn Use clear plastic, tin or organic mulch to kill turf in small areas. Apply in spring/summer and remove just before early winter seed sowing. Secure plastic and tin so they don't blow away.

For areas larger than 5,000 square feet use an herbicide like Roundup (generically called glyphosate) or Rodeo near water to kill existing turf. Apply once or twice in late summer and fall for early winter seed sowing. When using herbicides, always wear protective eye and skin protection.

If you are starting with an old field or highway right-of-way it is impractical to use mechanical means to remove weeds, however small numbers of trees and shrubs can be cut down and roots dug out using hand tools.

The preferred method is to use glyphosate (or Rodeo near water) to kill grasses and broad-leaf weeds. Use Roundup Pro or Garlon to kill undesired tree saplings, shrubs and vines (if woody plants are too big, they must be cut down and removed from the site). Apply in mid-summer, late-summer and fall for early winter seed sowing. Old fields typically have a diversity of grasses, broadleaf weeds and brush and may require more herbicide applications than a lawn. The table below lists difficult weeds and suggestions for their control.

Tree saplings and shrubs like oaks, hickories, hackberry, blackberry, sumac, sassafras, autumn olive, or woody vines, like trumpet creeper and grape, can be a problem if not killed before sowing seed. A stronger herbicide like Roundup Pro or Garlon 4 may be needed. See table below for treatment instructions.

Various size herbicide sprayers, left. 50 gallon spray rig with a 15 foot boom is practical for sites larger than a half acre, right.

Soil Preparation

After existing vegetation is killed, the ground should not be tilled, disked, or plowed. Disturbing soil brings up weed seed. Dead vegetation should be cut to a few inches high, using a mower or weed whip. Having some dead vegetation helps to hold seed in place and prevent erosion during winter months. Seeding can be done directly in the mowed dead vegetation in early winter.

Slopes:

Steep slopes can pose problems. Slopes with a grade above 10% may need to be stabilized.  There are several materials available to keep seed, plugs, and soil in place while plants become established.

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Seed Collection

Small quantities of seeds can be collected by hand or with pruners. Good containers are apple picking bags, paper or plastic grocery bags, and buckets.

Collecting grass seed using pruners and apple picking bags, left and center. Hand stripping seed into a 5-gallon bucket, right. It is easy to cut a hand while using pruners. A bag tied around your waist lets you use both hands.

Determining Ripeness:

Unripe seed heads are green or still have color in their flower petals. Wait until petals turn tan or brown. Sedge, left. Black-eyed Susan, middle. White wild indigo, right.

Ripe seed heads are tan, brown or black. Sedge, left. Black-eyed Susan, middle. White wild indigo, right.

Local Ecotype Seed: This seed originates naturally near your prairie project. The closer the seed originates to the project site, the more likely the plants will succeed, because they are genetically adapted to the environment and are more disease resistant. When purchasing seed, ask for seed that comes from as close to the project site as possible. Click on the following link for more details: http://www.for-wild.org/download/LocalEcotypeBrochure.pdf

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Seed Drying, Cleaning and Storage

Drying: Seed can be dried in cardboard trays, open paper bags or other open containers. Large quantities of seed should be spread out in a large, dry place. It takes about two weeks for seed to dry (dries more quickly in air-conditioned environment). Be sure to include the plant name, date collected and location of collection with your seed.

Labeled seed being dried in cardboard trays, paper bags, and on a sheet of plastic.

Cleaning: Seeds may be cleaned in kitchen colanders, sieves, window screens and other household items. Large wooden screens may be made of variously sized metal screening purchased from a hardware store.

Seed heads are cleaned in different size screens. Seed and fine particles fall through. Stems and larger parts stay on top.

Storing: Once seed is dried and cleaned, it may be stored in zip-locks or paper bags. These can be stored in a refrigerator or in a garage or basement as long as they are dry, mouse-free and out of direct sunlight.

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Seed Mixing

Getting Started: Mix 50% native grass seed with 50% forbs by weight (forbs are non-grass, broad-leaved flowering plants like black-eyed Susan). Pre-mixed prairie seed can be purchased from local native plant nurseries (see nursery source list). Try to acquire seed from Missouri or nearby since it will be hardier and more disease resistant in our climate.

PLS: You need 10 lb. pure live seed (PLS) per acre (15 lb. if seed is chaffy or not pure live seed). If you decide to collect seed yourself, use the 15 lb.-per-acre weight. For example, if you have a four-acre prairie you need either 40 lb. of pure live seed (PLS) or 60 lb. of chaffy seed. (For smaller sites, sow 1 oz. mixed seed per 200-300 sq. ft.)

Inoculants: Sites with degraded soil fertility may benefit by incorporating a mycorrhizal inoculant with the seed mix just prior to sowing.  Inoculants add beneficial microbes to the soil. 

Here is a sample seed mix for a one-acre mesic to dry prairie.

An acre contains 4,840 square yards or 43,560 square feet. If your plot is about 200 feet by 200 feet then you have 40,000 square feet or just under one acre.

Here is a sample seed mix for a one-acre mesic to dry savanna or open woodland.

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Seed Sowing by Hand

When to sow seeds. Early winter is the optimum time to sow seed because most native wildflower seeds germinate better after exposure to cold temperature. This process called stratification happens naturally each winter. Without stratification, seed germinates at the wrong time and does not survive winter. Sow seed in November or December, if possible (early January at the latest).

Sowing seed on slopes. When sowing seed on slopes, incorporate a nurse crop such as oats or annual rye. Nurse crops can be planted with your seed mix to prevent erosion and reduce weed growth during the first growing season, but are ideally sown in November. Nurse crops typically disappear by the second growing season. Do not to use winter wheat or winter rye as a nurse crop. Studies have shown that they produce chemicals that prevent germination of prairie seedlings.

Mixing seeds. Mix seed with a larger volume of slightly moist sand, sawdust, or similar inexpensive material to improve seed distribution. Four parts sawdust to one part seed is a good percentage. Seed is mixed with moist sawdust.

"Every American has the right as part of his cultural heritage to stand in grass as high as his head in order to feel some small measure of history coursing his veins and personally establish an aesthetic bond with the past." -William H. Elder

This image depicts a large volume of seed being mixed with moist sawdust. White fluffy seed on top is showy goldenrod.

Sowing seeds. Sow using a grid-shaped pattern spreading half the seed mixture over the entire area in one direction. Then use the other half over the same area, spreading it in the other direction.

Seed sowing can be done by hand if the site is less than five acres. Use a commercial seed drill for larger plots. Ten people can sow seed over 5 acres in a morning. Here are some tips for hand seeding.

• Line up helpers evenly at the edge of the plot. As they walk forward, they should keep the same distance apart. It helps for people at the leading edge of the row walk toward a landmark that helps them stay on course.
• Fan seed out in front of you as it is thrown. Avoid throwing clumps of seed mixture in one small area.
• Sowing seed on snow is ok, but some seed may be eaten by birds. Sowing seed on a steep slope may result in seed washing away in a heavy rain. You may need to use erosion mats on steep slopes. Gentle slopes are fine.
• Sow seed on undisturbed ground. Tilling, disking or plowing brings unwanted weed seeds to the surface. During winter freezes and thawing, seeds sown on the surface work their way into the soil to the proper depth. Therefore, there is no need to cover the seed or rake it in when sowing.

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Sowing Seed with a No-till Seed Drill

This method is used for plots larger than an acre. No-till seed drills plant the seed in rows by cutting slits in the soil and planting seed at the proper distance, and depth. No-till drills cause minimal soil disturbance which results in less weed seed germination. Seed drills may be borrowed from various state agencies or hired through a landscape contractor who specializes in prairie seeding. To learn how to borrow and use a no-till seed drill, contact the Missouri Department of Conservation private lands conservationist in your county. They are listed at http://www.mdc.mo.gov/landown/contacts.html

Commercial seed drill

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Spring Germination

Prairie seed begins to germinate in April and continues through June. Some germination even occurs the next spring. Seedlings may be difficult to see because of their small size and the annual weed competition.

Six week old prairie seedlings. Swamp milkweed, left. Wild bergamot, center. Prairie blazing star, right.

You can learn to identify prairie seedlings by sowing seed of each species indoors. Seed should be kept in moist sand in a zip-lock bag in the refrigerator for 2-3 months and then sown in pots to germinate. As seedlings germinate, you will notice differences in each prairie species. Compass plant, left. Wild Bergamot, middle. Switch grass, right.

To see more prairie seedlings visit http://mdc.mo.gov/grownative/plantID/

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Maintenance

What to do in year one. Vigorous annual and biennial weeds can shade out prairie seedlings during the first summer because prairie wildflowers and grasses grow more slowly than annual and biennial weeds. Control weeds by keeping them mowed to a height of 6-12 inches throughout the first growing season. Most prairie seedlings are less than 6 inches tall in their first growing season and are seldom damaged by mowing. Do not allow weeds to get over 12 inches before cutting because tall weeds will shade out small prairie seedlings and long clippings can smother small seedlings. Keeping weeds cut back the first year also prevents production of more weed seeds that could become a problem in the future. Keeping weeds mowed on a regular basis in year one is an important step for a successful prairie seeding.

Best equipment to use. String trimmers work well on projects less than an acre. Tractor-driven mowers are needed for larger areas. Adjust mower to cut higher than 6 inches.

Common weeds. Common biennial weeds include Queen Anne's lace, bull and Canada thistle and curly dock. Common annuals include moth mullein, fleabane, mare's tail, foxtail grass, chicory, ragweed, lambs quarter, mustard and smartweed to name a few.

Weed with care. Pulling weeds in year one can cause problems because prairie seedlings are small the first year and are easily pulled up with the weeds. However, if you know how to identify young weeds, it is safe to pull them, as long as you do not disturb nearby prairie seedlings. Keep in mind that pulling weeds disturbs soil and can expose new weed seeds. To remove large weeds, cut them off at the base and remove any seed heads from the site.

What to do in year two. If weeds are a problem mow them at a height of 12 inches since prairie seedlings will be taller the second year. If biennials are a problem, mow them at 12 inches when they are in full bloom. This should kill them or set them back severely.

Long-term maintenance. If burning your prairie is not an option, mowing will work once your reconstructed prairie is established. A late winter or early spring mowing is recommended once every year or two to cut back trees and shrubs. Standing prairie plants are full of over-wintering insects and provide food and cover for winter birds.

First year prairie receiving mowing, left. Established prairie receiving annual late winter mowing, right.

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Species Selection Guide

Click on the scientific name in red to find more information.  The links will take you to the Grow Native! Plant Identification webpages, the Missouri Flora webpage, and the USDA plant database.

Grasses, Sedges & Rushes

Forbs (the non-grass plants often referred to as prairie wildflowers)