The Scott County IRVM Plan was created in 2016 and one of the top functions is to restore and reconstruct native vegetation in the county right-of-way. These pages will explain the benefits of native vegetation and the reconstruction process.
BENEFITS OF NATIVE VEGETATION
- Native plants are durable, long-lived perennials well-adapted to Iowa’s climate and growing season.
- A diverse native planting adapts to a wide range of soil and moisture conditions.
- Native plants perform well in poor soils.
- Extensive, native plant root systems provide superior erosion control.
- Deep roots and dense, above-ground foliage reduce stormwater runoff by intercepting raindrops, slowing water flow and increasing infiltration.
- Extensive roots and decaying foliage further increase stormwater infiltration by adding organic matter to the soil, making it spongier and more absorbent.
- Root systems penetrate 6-8 ft. or deeper, enabling prairie plants to survive drought and high salt concentrations.
- Extensive root systems deprive weed roots of water, nutrients and space.
- Tall prairie vegetation shades out Canada thistle and other weed seedlings.
- A wide strip of prairie grass in the right-of-way traps blowing snow, increasing the storage capacity of the ditch and reducing the amount of snow deposited on the road.
- Native roadside plantings provide valuable food and cover for songbirds, game birds and small mammals.
- Native roadside plantings provide important habitat for agriculture crop pollinators.
- Native plants add color and natural beauty to the right-of-way.
- Tallgrass prairie roadside plantings restore a piece of Iowa’s natural heritage.
Due to native plants slow growth they struggle in their early stages competing with weeds. Weeds are non-native plants brought over from different continents. Weeds seem to be everywhere competing with native plants for nutrients and space. Spreading aggressively and causing problems. The first step in soil preparation is to remove the existing vegetation. Below are listed several common methods to re-move existing vegetation.
- Use a vegetation killing herbicide (glyphosate) at least two times.
- Prescribed burn to remove dead vegetation.
- Cover the area with black plastic, cardboard, plywood, or mulch for one growing season.
- Rototill or disk the area at least every month for one entire growing season.
- A combination of the listed methods.
PLANTING NATIVE SEED
Soil seed contact is necessary for seed to germinate. For optimal results plant your seed mix either be-fore June 15th or after October 15th. Some species establish better when spring planted, other species establish better when fall planted and some are difficult to establish whenever they are planted. Re-gardless plant when you can. Prairie seed can be planted by broadcast seeding, hydroseeding and drill seeding. Proper depth is essential for germination. Plant the seed too deep and it will not survive. Con-tact the seed distributor for proper depth ranges. For best results incorporate soil amendments such as organic matter before planting. If possible after planting watering may help depending on the time of year. Below are common seeding technics.
STAGES OF NATIVE PLANTINGS
- YEAR ONE- Native seedlings will not get very tall during the first growing season. The annual weeds such as foxtail and ragweed that occur naturally, along with stabilizing nurse crop seedlings such as oats or winter wheat that are planted with the mix, are mowed frequently to reduce competition for sunlight and nutrients. The area may be mowed to a height of 4-6 inches whenever vegetation grows 12-18 inches high in the first growing season. Most prairie seedlings do not grow taller than 6 inches high in the first growing season and will not be damaged by the mower.
- YEAR TWO– Stabilizing crop seedlings will begin to be replaced by native long-lived perennials. Some native species will mature and produce seed. Some weedy non-native biennials may be mowed once or twice to reduce competition. To avoid damaging native plants, during the second growing season the mowing height should be at least 12 inches. Perennial noxious and invasive weeds present may be carefully spot sprayed. Be sure to follow pesticide regulations.
- YEAR THREE– Annual weeds should be nearly gone. Native species such as partridge pea, black-eyed susan and Canada wildrye, visible in years one and two, will be joined by other grasses and wildflowers.
- YEAR FOUR– Native perennials will begin to occupy the space and outcompete weedy species. Some native species can take up to six or more years to mature and produce seed.