Proper soil preparation is probably the most important factor in the success of a prairie planting. The seed bed must be weed free and free from dirt clumps. If existing weeds are not killed when planting they will compete with new prairie seedlings for nutrients, water and sunlight. If not controlled, they considerably delay the growth of your prairie planting. A smooth, clump-free seed bed will insure good seed soil contact between the soil and seed, giving you the best germination results when first planting.
The first step in soil preparation is to remove the existing vegetation. You can do this by smothering, cultivating, herbiciding or in combination.
On small areas of a few thousand square feet or less, smothering or choking off weeds is simple, effective, and requires no chemicals or special equipment. Smothering or choking involves covering the soil surface with black plastic, boards, tarps, or a thick layer of leaves. Soil is not suggested because weeds can grow thru the soil or weed seeds will be exposed to water and sunlight and will germinate. This should be left in place for a full growing season in order to kill the existing vegetation.
Another method commonly used to prepare soil for planting involves the use of a short duration herbicide like Round-up, KLEENUP, or Ranger. Most weed killing herbicides only kill existing plants. Weeds must be present and growing to be killed. When using herbicides, read the label, and follow the manufacturer's instructions. When the site seems ready for planting and time is available continued spraying of a weed herbicide can be done. The area can be continued to be watered and as weed seeds germinate spray them. After the final spray wait at least 10 days and sow seed on soil surface. At the Prairie Frontier wildflower farm we do not use herbicides but use methods that take longer but eliminate the use of toxic chemicals.
Another method is the tilling method. The planting site can be disked, plowed or tilled 4"-5" deep. For best results it should be continued all season every 2 weeks until fall. This process destroys the rhizomes and roots of perennial weeds and plants. If you have quack grass or other similar species you will need to cultivate one full growing season to get rid of these perennial weeds. Bringing these roots to the surface and letting sunlight destroy their life cycle is the best method to kill them. In the final stages of tilling or disking decrease your depth to about 1" because you will not want to bring up annual weed seed. Thousands of weed seeds are dormant beneath the soil surface and bring those up continue the weed problem. After perennial roots are killed and top surface weed seeds are killed your bed is ready for planting.
When planting a field that has been previously sprayed with long lasting herbicides such as Atrazine, investigate the sites herbicides history for carry-over residues can kill freshly germinated prairie seedlings and you should follow the chemical companies carry-over waiting recommendations.
When Should I Plant
Fall planting has a major advantage because of the natural "wintering over" process which is required for a lot of the native species. Planting at this time helps break down the seeds germination inhibitors associated those species. Fall planting in the Midwest region is from mid October to December. Some annual seeds can germinate with moisture and 70 degree temperatures so that must be kept in mind so that seedlings do not sprout only to be killed by winter freezing. Erosion prone sites should be planted with a cover crop of oats or annual ryegrass.
Spring - Summer Planting
Spring planting can be done anytime the ground can be worked. For native seed species that need to break their dormancy, early spring planting does this. Seeds need approximately 70 degree temperatures to germinate, so don't expect much until those temperatures are more common. Erosion prone sites should be planted with a cover crop of the Prairie Frontier non-hardy annual wildflower mix. Spring planting is ideal because the common spring rains help the establishment of a prairie or wildflower planting. Summer is a good time for planting also, if you can help with watering for at least 4-6 weeks after sowing the seed. Sometimes it takes all of spring to get planting sites free from weeds or under control and planting is commonly done at this time. It takes approximately 70 days for a perennial seed to become established. Under normal growing conditions you don't time to run into a hard fall frost. When a Prairie Frontier non-hardy annual cover crop mix is used in conjunction with prairie mixes, under ideal temperature and moisture conditions you can expect blooms in 60-70 days.
Sowing the Seed
The method of seeding application depends upon the amount of area to be seeded and the terrain. On small areas, hand seeding or a cyclone spreader will do the job. It is highly recommended that you add a carrier (damp sawdust, dry sand, and/or vermiculite) to a mix of seed. The idea is to dilute the seed into a larger amount or add volume to the seed so that you will not be sowing seed too thickly or heavily into an area. We recommend that you take half the seed mix with carrier and try to cover the complete area to be planted. Then take the remaining seed mix and seed areas missed, shorted, or a double pass to insure an even seeded area. This way you will have plenty of seed. When seeding a large area of 1 acre or more, drilling is another option. Drill seed to a maximum dept of ¼". After seed has been sowed, a light raking to cover the seed is recommended. Do not bury the seed too deep. Common rule is to bury the seed the depth of what its diameter is. Large areas can be dragged with a cyclone fence. Once the seed is covered or lightly raked, the seed bed should be firmed. This can be done with a roller or even driven on. Small areas can just be walked on repeatedly. What the seed needs is the soil packed around it tight so moisture can penetrate the seed coat. On erosion prone sites hydroseeding is recommended but you should use double the rate of suggested seeding rate per square foot. Hydroseeding is the spraying of a glue/seed mix and all seed is not in contact with the soil at time of application. Mulching can be done, if only done lightly, and if marsh hay or straw is used it must be free from weed seed. Using field hay that is not weed free may be introducing millions of weed seeds into your planting.
Watering spring and summer plantings will be very beneficial if rain is not present. Watering at least ¼" per week will help the germination of seeds and the establishment of plants. Over watering sometimes can encourage weed growth. Watering in the late afternoon or evening will be the most effective in the early stages. Once plants are established and shading of young plants is present watering in the morning can be helpful. It is important to keep seeds moist for germination but not soaked in water. If you have clay soil caution should be used because it retains moisture.
Cover crops are helpful for several reasons. A site that is being prepared to be planted the following year will have to sit through the winter and should be planted with field oats or an annual ryegrass. The Prairie Frontier non hardy annual wildflower seed mix can also be used as a cover crop in a spring or summer planting to help erosion, help choke off weeds and also bring color to your first year planting as perennial seeds will not bloom until at least the second or third year of growing. If the annual wildflower cover crop is used, a time frame should be considered, so there is enough time in the growing season to enjoy the bloom period. The Prairie Frontier non hardy annual wildflower mix can produce blooms in 70 days if moisture and temperature are ideal. This annual mix is widely used in prairie mixes in the midwest because the annuals used will not persist much after the first year and should diminish in a couple of years completely.
Cover Crop Seeding Rates- Pounds Per Acre
( 1 Acre = 43,560 square feet)
Note: One bushel of oats weighs approx. 32 lbs.
||Prairie Frontier non hardy
annual wildflower seed mix
(cover crop only)
(plant Aug to Sept for establishment)
(with Native Mixes)
(plant after hard frost)
|Spring or Summer
(with Native Mixes)
The most common reason wildflower and prairie grass plantings fail is because of weed control. There is no easy solution, but having patience is a key factor. Prairie Frontier believes that with some effort a wonderful wildflower and or prairie grass planting can be established. In most cases the first year will be the most difficult and will improve the second year and after. Here are a few helpful hints and tips to help you if you need help.
Perennial wildflowers and prairie grasses take time to establish and are slower growing than most annual weeds, this is most prominent during the first growing season. The perennial wildflowers and grasses will be present, but will be less noticeable when using the Prairie Frontier non hardy annual wildflower seed cover crop mix. The annual wildflowers will be noticeable and should grow at almost the same rate as weeds. The perennial wildflowers and grasses will only reach a height of about 6" in the first growing season. If the non hardy annual mix is not used you can cut the plantings back 4"-6" during the growing season. The idea is not to let weeds go to seed, which only to germinate next year, letting the weeds totally dominate the planting. Also, the weeds use most of the light and moisture available, choking out all the perennial plants trying to establish themselves. If the Prairie Frontier non hardy annual wildflower mix is being used it should help compete with the weeds and not compete with the perennial wildflowers and grasses. If the weeds totally take over and go to seed, using the annual mix and a cutting should be done about 8 inches (this is not common). The annual wildflowers will continue to grow and continue to bloom once again. We believe that hand pulling of weeds can be done if you can properly identify them, being careful not to pull out other existing small wildflowers or grasses. No sense letting a large weed dominate a large area of a planting using the light, soil, and moisture that could otherwise go to new wildflowers or grasses. Care must be taken! If you have a small planting you can go in snip with a scissors any unwanted weeds especially before they go to seed. They are most likely annual weeds. If you have a very large planting, try spot spraying with general herbicide or selectively cut weeds with a string trimmer. Prairie Frontier does not suggest planting any fescue grasses or clovers with their wildflower mixes as they become too aggressive in the establishment of wildflowers and prairie grasses. Another concern is weedy or noxious plants located adjacent to your planting. In the event they creep towards your planting use care to try to control these species so they do not over come your planting.
It is generally unnecessary to fertilize wildflowers and prairie grasses if they are planted in their native habitat. In fact fertilizing may produce excess foliage at the expense of blossoms. Also fertilizing the first year may encourage more weed growth.