Wildflower plantings can provide a colorful alternative to high maintenance, mowed areas. The beauty of a wildflower display will often be more spectacular during certain times of the year, depending on the species composition.
Most people do seem to enjoy a planting of wildflowers. However, if your idea of a perfect landscape is immaculately clipped and manicured, then wildflower plantings will probably not suit you.
Wildflowers often look a little ragged once they've gone to seed. For the first year or two after planting, weed encroachment can be a serious problem. Unfortunately, even a weed-free wildflower patch may look weedy to some people.
Many wildflowers will thrive even when neglected, if they are established on a favorable site. In difficult locations, few will survive. Most native prairie plants do best on well drained soils in full sun.
Growing wildflowers from seed requires more than the usual amount of time and work. Like any kind of planting, success requires careful preparation and choosing the right plants for the location.
Begin your planting site preparation by eliminating weeds. Cultivate monthly 2 to 3 inches deep or apply Roundup (glyphosate) herbicide at ten day intervals until no more weed seed germinates. For smaller areas, cover with black plastic for one growing season.
Another option is to treat small areas with a soil fumigant such as Vapam or Basamid. You must be a certified pesticide applicator to apply Vapam but not Basamid. Always read and follow all label directions.
You must incorporate granular Basamid into the soil. Then compact the soil surface with a roller and moisten the soil surface so that a crust forms to seal in the gas that develops. The soil must be kept uniformly moist for 7 to 10 days. Then cultivate the soil and wait 2 to 3 days for the gases to escape before planting.
Wildflower seeds are easy to plant with a slit-seeder or a drill-seeder if the seeds are larger than one-eight inch in diameter. If you don't have access to one of these machines, then you can rake the seed into the soil with ordinary lawn rakes or landscape rakes or drag the seed in with a section of chain linked fence pulled behind a tractor or riding mower. Try not to cover the seed more than 1/4 inch deep.
Before planting small seeds that are dust size to one-eight inch in diameter, mix them well with moist sand. Use about 3 to 10 parts sand to about 1 part seed. Broadcast the mixture using a hand-held or pull-behind cyclone seeder. Sow seeds in two directions for more uniform coverage but don't cover the seed. Roll the seed bed to get good seed-to-soil contact. This is essential for good seed germination.
You can plant wildflowers in spring or summer (April through July), late winter (February and March), or fall (October through December). For best results with spring or summer seedings, keep the seed bed moist for 3 to 6 weeks after planting. After the seeds germinate, put on 1 to 2 inches of water once per week until the seedlings can survive on their own. For late winter and fall seedings, prepare the seedbed during the season prior to planting. Broadcast the seed and allow the freezing and thawing action of the soil to "plant" the seed.
During the first few years after planting, hand weed or use Roundup as a spot spray or wick-wipe application. Mow the planting at a height of four inches. As the season progresses, gradually raise the mower height to the highest setting. Stop mowing as soon as the annual flowers reach that height. In March or April of the third year, burn the entire area. During the fourth and subsequent years, burn about a third of your total planting each year in March or April. Before burning, notify neighbors and the fire department and make sure the speed and the direction of the wind are safe.
An alternative to burning is to mow once per year, usually in late fall. You may rake-up the cut material or leave it in place to serve as a mulch. Over-seed any bare spots, weed regularly, and irrigate during drought.
Your wildflower planting will be only as good as the seeds you sow. If you invest the time and energy to plant correctly, don't ruin the project by using questionable seeds.
Be leery of seed mixtures that contain a high percentage of annuals or introduced species. Native perennial species will take longer to establish than annuals, but they should be better adapted and more permanent than introduced species.
Buy from a reputable seed dealer who can provide information about individual species and mixtures. For a list of wildflower seed suppliers in Iowa and neighboring states, contact your local county ISU Extension office or the UNI Roadside Program. 113 CEEE, Cedar Falls, IA 50614-0293, telephone: 319-273-2813.
This article originally appeared in the May 19, 1995 issue, p. 71.