United States Department of Agriculture

Iowa Native Prairie Planting Guide

(Brome, Orchard, Fescue, Bluegrass)

1. Late Summer - Start the sod to prairie conversion 

process. Mow existing grass (4-6” ht.) between Aug. 

2 and Sept.1. (The earlier, the better to ensure time for 

regrowth during dry conditions. Haying is preferred 

over mowing, but follow program rules.)

2. Early Sept. to Mid Oct. - Apply glyphosate herbicide 

at 2 quarts/acre when the active ingredient is 41%. 

Use 3 quarts for hard to control species such as 

Canada thistle, clovers, reed canary grass, and fescue. 

Follow the label for specific rates, adjuvants, etc. 

Adding 2,4-D Ester can help with difficult to kill 

perennial broadleaves, i.e. clovers. Apply after there is 

6-8 inches of regrowth. Good growing conditions are 

required (overnight lows 40F+, daytime high 60F+) 

when and after you spray for 2-3 days.

3. Early Spring (optional) - Burn off dead plant material 

in early spring with fire. This will: 

a. encourages a flush of regrowth from any living 

brome in the Spring;

b. encourages a flush from seed bank (i.e. red clover, 

annual weeds);

c. remove duff layer;

d. allow better herbicide contact;

e. make it easier to plant into; 

f. allow you to see hazards such as: ant hills, badger 

holes, and tile breaks. Use combination of disk and 

blade to smooth those areas.

4. Late May - Apply glyphosate herbicide to the area to 

be planted after green up. 

Spraying in the spring is not sufficient to kill the 

existing perennial vegetation. If you are starting 

this process in the spring, spray and then leave the 

ground fallow for the first growing season. 

5. (Option 1) Late May to Early June - Plant mixed 

native grasses and forbs with a native no-till drill 7+ 

days after the herbicide application. Chemicals need 

time to translocate into the root system of emerged 

vegetation. Cutting up sprayed grass could affect the 

performance.

a. Drill shallow: 1/8” for forbs, 1/4” for grass.

b. Broadcast and roll only if > 50% of soil is exposed. 

5. (Option 2 - Preferred) Leave area fallow for the 

growing season

a. Spray 1-2 times during the summer when 

majority of weeds are < than 12” tall. 

Caution: Don’t let weeds get too tall. They will 

be harder to kill, and you don’t want them to add 

seed to the seed bank. Weeds in a fallow field left 

unchecked can produce a tremendous amount of 

weed seed. 

b. Spray again in September – first 1⁄2 of October

c. Complete a dormant seeding by drilling (or 

broadcasting if 50% or more soil is exposed). 

Natural Resources Conservation Service, Des Moines, Iowa, August 2018

Planting Native Prairie 

Into Cool Season Sod

USDA is an equal opportunity provider, employer and lender.
Planting Native Prairie Into Cool Season Sod

Other Considerations:

» Seed forbs on the surface or a shallow depth (up to 1/8” 

depth). Grasses do fine planting up to 1/4” depth. Some 

seed on the surface is ok.

Tip: When using a native grass drill, disconnect every 

other tube on the forb box, so seed lands on the ground. 

» If you are trying to complete a seeding in an area 

with reed canary, develop a long-term plan to kill it 

completely (very difficult) and a proper seed mix that 

will compete with it. 

» Do not use fertilizer because it will only help the weeds 

out-compete your seeding.

» When broadcasting, rolling will help with seed to soil 

contact and to reduce predation of seed from birds, 

mice, and night crawlers. 

» When seeding small areas or when broadcasting seed, 

add a carrier to help ensure you don’t run out of seed 

(i.e. rice hulls, cocoa shells, pell lime, ground cobs). 

Consider broadcasting the area twice to ensure good 

coverage.

» On small areas (< 2 acres), you can seed from a bucket. 

• Flag off lines every 50’ to help stay in line. 

• Use sand as a carrier - 2 parts damp sand to 1 part 

seed, minimum. 

• Weigh seed and separate into buckets. 

» Adding 1⁄2 - 1 bu. of oats to spring seedings can reduce 

erosion.

» For High-end Seedings (pollinator/CP-25 /prairie 

reconstruction):

• Ideal mix is: 25-50% grass/50-75% forbs.

• Strive for diversity. 

• Limit amount of tall warm season grasses (Big 

Bluestem, Indian Grass, & Switchgrass). They 

establish quickly and can out-compete forbs. 

Recommended seeding rate: 0.1 (1.6 oz. or 0.4 

seeds/ft2) to 0.25 lbs. (4 oz. or 1.0 seeds/ft2) each for 

Big Bluestem and Indian Grass. Limit Switchgrass 

to the 0.1 lb. rate. Other native grasses are not as 

competitive.

» Native grasses are an important component of the tall 

grass prairie. Less favorable grasses such as woolly 

cupgrass, smooth brome, tall fescue and quack grass 

will take over if native grasses are excluded.

» Consider Iowa ecotype seed (originated from prairie 

remnant plants) for long-term to permanent seedings. 

» Use high end seedings around the farmstead for added 

beauty.

If you have additional questions, contact your local NRCS 

Field Office, Iowa Department of Natural Resources (DNR) 

biologists, or Pheasants Forever biologist for further 

guidance.

If Tillage Is Necessary 

» Tillage is only recommended when the field is very 

rough from gophers, etc. 

» Several tillage passes will be required to prepare an 

acceptable seedbed. 

» The downside of tillage is that it can increase weed 

pressure.

1. If you decide to till, follow steps 1 and 2 from the 

previous page. If the field is too rough to mow, then 

skip step 1 and go to step 2.

2. Perform Tillage

» If spraying occurred, complete tillage in the 

spring to smooth the area.

» If no spraying occurred, deep tillage will be 

required in the fall to kill the cool season stand 

using a plow or chisel plow, followed up in the 

spring with a disk and a field cultivator.

3. Seedbed must be rolled 1-2 times before planting to 

create a firm seedbed. 

4. Drill or broadcast, and then roll again.

Fall/Dormant Seeding

Fall/Dormant seedings can be conducted Nov. 15 through 

April 1, or until the freeze/thaw season ends.

» Advantageous to the forb component. Germination 

increases for many forb species if they go through 

freeze/thaw cycles. 

» Need > 50% of soil exposed.

» In diverse forb mixes, seed 0.25 lbs. (4 oz. or 1.0 seed/

ft2) each of Big Bluestem, Indiangrass and Switchgrass. 

Dormant seedings are not as conducive as a spring 

planting for the tall warm season grasses. 

» Broadcast and then roll. If the ground is frozen, don’t 

roll.

» Don’t broadcast seed on ice covered ground, snow 

crusted ground, or when snow cover is > than 4”.