Introduction-These recommendations for planting tallgrass prairie from seed
are based on 35 years of planting experience. At some point during that time every conceivable
mistake was made. While these planting methods are not absolute, like most farming practices
basic procedures give acceptable results under a wide variety of field and weather conditions-even
on very dry years.
Identification-Before attempting to reconstruct even a yard-size prairie, try to spend at least one season becoming familiar with the grasses and flowers in a virgin prairie remnant. Visit your selected area at least once a month from May to November.
Site Selection-Start small even if you have unlimited financial resources. If possible have someone who has planted before evaluate the sites potential.
Seed Selection-Try to use as much variety (diversity) of local ecotype seed as possible. Find out the components of the prairie matrix. The greater the diversity you plant, the better your prairies long-term stability.
Soil Preparation- Till soil every three weeks by shallow disking or field cultivation to remove as many weeds as possible. If the area contains heavy stands of smooth brome, reed canary grass, quack grass, or Canadian thistle, consider spraying emergent green vegetation with the herbicide Round-up™. It is systemic and will kill the plant's root systems and prevent serious problems later. Before planting harrow and roll using a cultipacker or cast-iron field roller to get a good firm seedbed. Crop field plantings are now being done with no tillage in late fall following soybeans or corn with very good results.
Seeding-Seed about 10 to 15 pounds of mixed flowers and grasses per acre using at least 2 times the weight of forbs (flowers) as grass seed. Use a 10-pound rate for certified seed and a 15-pound rate for hand-collected seed. Plantings done in mid to late June tend to have fewer weed problems than those seeded in May, and heavy rains are less likely than in early spring. Some species, however, need cold stratification to germinate and may not emerge until the following spring. Older Truax drills work great for clean seed, however, only newer Truax no-till drills will work with combined seed that contains broken leaves, stems, and other debris. We have found that a dry fertilizer spreader works best for seed mixed with heavy trash. They seed an area about 6 feet wide and can be rented from most local fertilizer dealers at a very reasonable fee. Fall seedings appear to give a wider variety of species an equal start. They should be done in late October or early November into lightly tilled soybean stubble or a late summer-seeded oat stand without tillage. The oats will winter kill, but give the planting protection from heavy spring rains. We now do split seedings, applying half the seed in the fall and the remainder the following spring. After the seed is broadcast or drilled, harrow lightly and roll until the soil is very firm. Rolling is your best defense against water erosion when the soil is unprotected by vegetation.
Post-seeding Management-About 3 weeks after seeding (or in mid-June for a fall seeding) begin to monitor for weeds. You will not likely find any emerging prairie grasses or flowers. After weed growth is about 10 inches to 1 foot in height, mow back to 2 to 4 inches with either a sickle or a rotary mower. Depending on the rainfall mowing may be required every 3 weeks until mid-September. Gradually increase mowing height to 8 inches. If no weeds are present, which is unlikely, mowing is unnecessary. Do not use herbicides for broadleaf weeds unless no forb species have been planted. Pure grass stands may be sprayed with broad-leaf weed killers such as 2-4-D at a rate of 2/3 pint to 1 quart per acre without damage to grasses. Broad-leaf weed killers do not kill foxtail or other cool-season grasses, so mowing may still be required. This post-seeding weed control is the most important part of a successful establishment, especially on a dry year.
Second Season Management-Occasionally mowing may be required to control foxtail in mid-summer where grasses have not become well established. It should, however, be no shorter than 8 inches in height. Most management should be limited to the pulling of problem weeds, or chemical treatment of individual plants such as Canadian thistle or sour dock. Caution should be exercised when using Round-up™ since it will vaporize when the air temperature is above 80° F and may kill plants around treated weeds. Individual Canadian thistle plants cannot compete with vigorous prairie stands and in most cases are smothered out in 3 or 4 years. Patience is important since some prairie species such as little bluestem, compass-plants, and indigos will not make much of a showing until the third growing season.
Third Season Management-Burn if possible in late March or early April. Most species should respond to fire and have enough root establishment to flower. Weeds should be minimal and can be pulled individually. Mowing should not be considered unless very heavy foxtail stands persist, which could indicate that the seeding has failed to establish and may need to be done again.
PS. We have many demonstration plots on our farm 1 mile west of St. Anthony in Western Marshall County. We welcome visitors. Please e-mail ahead so we can plan to give you a tour.
1562 Binford Ave.
St. Anthony, IA 50239