Habitat loss and degradation occurs every day in Teton County. Despite the vast surrounding natural beauty, there are portions of our landscape negatively impacted by both natural and human-induced disturbances. These disturbances, such as fires, mudslides, and the construction of roads, trenches, and buildings, have left our landscape vulnerable to weed invasion. Invasive species have the ability to damage ecosystems by degrading habitat, altering nutrient cycling, and displacing native plants and animals. Removing the invasive species is only one part of the solution. The restoration of disturbed land is essential to habitat recovery. The goal of this section is to provide the steps necessary to combine invasive plant control with the establishment of desired plant species to help improve the chance of restoration success.
Defining project goals and objectives is the most important step in planning a weed management or restoration project. To restore habitat most effectively, planners need to clearly identify the target species and why they are doing it. For example, if the target species is livestock, then the goal state could be a sustainable pasture. In contrast, if sage grouse is the target species, then native sagebrush habitat would be the goal state. The ‘goal state’ for restoration sites should account for; understanding restoration species requirements, what their healthy habitats look like, how ecological communities function and how those communities may change over time.
Total Acreage and Infestation Density – Determine the number of acres that are weed infested and in need of revegetation. Areas where invasive plants make up more than 30% of the total species are key candidates for revegetation (Goodwin, et al., 2006). These areas with dense weed infestations are better suited for revegetation because there are few desirable species in the area to naturally reseed after the invasive species have been removed. Sites with small weed infestations can be brought to the desired goal state by controlling the weeds and allowing the surrounding vegetation to fill in.
Weed Control – Contact TCWP for a weed management plan. Generally, we recommend that treatments be made at least twice over the growing season. Treatment may take several years to reduce the weed seed bank enough to make revegetation viable.
Soil Condition – Before starting a revegetation project, have a soil sample analyzed. Good soil health is imperative to the success of restoration. On some sites, topsoil may have been removed or compacted during construction. Find out the soil needs and make amendments before seeding. We recommend soil testing through Utah State University.
When you will be able to replant an area may depend on what chemicals were used when the weeds were treated. Because invasive species are difficult to control residual, or long-lasting, chemicals are used to increase efficacy. While residuals are great for controlling weeds, they can also impact the growth of desirable plants. The following is a chart of common herbicides used in treating noxious weeds and the amount of time needed before reseeding (these are general guidelines, always read the product label):
Broadcast seeding – When seeds are broadcast, seeding rates are typically greater than 20 lbs/acre or one seed every 2.5 inches (Pawnee Buttes, 2013). To improve success of broadcasting it’s a good idea to increase seed to soil contact – which can be as simple as raking the seeds into the site or on a larger scale using a harrow. To further protect the seeds from predation and exposure – use of certified weed free mulch like straw can help successful establishment.
Hydro seeders apply the seeds to the soil surface in a water based slurry with a mulch tacking agent and often include fertilizer. It usually has a high degree of success and is often the best option for sites that have slope and potential erosion issues. There are several companies that provide this service in our area check the contact page on our website.
A drill seeder places seeds at a desirable depth and covers them with soil to seed at various rates. Drill seeding can be successful at rates as low as 8-12 lbs/acre. Drill seeders work well on flat and gently rolling sites but, may be dangerous on slopes – always refer to the user’s manual for guidelines.
Seeding of desired vegetation can be initiated at different times depending on availability of water. On non-irrigated sites, dormant seeding is required after the soil temperature has fallen below 55 degrees F for one to two weeks (Goodwin, et al., 2006). This period usually falls in late October or early November. It is important to note that moisture after planting should remain low enough to prevent germination. If conditions are not favorable for dormant seeding, early spring can also be successful in non-irrigated sites if late snow and spring rains are plentiful. Summer planting (late spring to mid-Aug) can be successful if irrigation is available.
The native grass mix is appropriate for a variety of sites where the goal is restoration to native species and where additional broad leaf weed management may continue. The pasture grass mix is primarily introduced grasses that are known for production as well as their ability to be competitive for resources with noxious weeds, especially when irrigation is available. The forbs mix is a list of widely adapted native forbs that may be inter-seeded into sites following successful weed control. TCD Seed Mixes
Seedling establishment is the most critical phase of revegetation. Many factors can influence establishment including variations in soil properties, site exposure, and climate. However, seedlings usually fail to establish due to insufficient soil moisture and intense weed competition (Goodwin, et al. 2006). Young grass seedlings (< 4 leaf stage) are sensitive to herbicide treatment. During the first 12 months the best control method for weed infestations is mowing. This control is recommended once weedy species reach 12 inches in height, or reach the “bud” stage.
Mowing at this stage allows moisture and sunlight to be accessed by seedlings rather than the weed species (Pawnee Buttes, 2013). Spot treatment with the use of herbicides before the 4-6 leaf stage can be effective; however caution should be used as non-target damage can occur. By replanting with grass species, broadcast treatments of weed species with the use of herbicide can be performed once grass seedlings have established a secondary root system (tillering and adventitious root development). A secondary root system is usually sufficiently developed by 45 to 60 days after emergence, depending on growing conditions (Dow, 2012). Be sure to follow the herbicide label. Once weed populations have decreased to tolerable levels, forbs may be introduced to the site. Heavy grazing is not recommended on replanted sites until two growing seasons have passed (Goodwin, et al. 2006).
Teton Conservation District (307) 733-2110
University of WY Extension Teton County (307) 733-3087
University of WY Extension Lincoln County (307) 885-3132
Natural Resources Conservation Service (307) 886-9001
Colorado State University Soil Testing Lab http://www.soiltestinglab.colostate.edu/
Utah State University Analytical Laboratory http://www.usual.usu.edu/
Seed mixes can be purchased from:
Big R Ranch & Home – (307) 201-1646
Wilson Hardware- (307) 733-9664
Pawnee Buttes Seed – (800) 782-5947
Wind River Seed – (307) 568-3361
Dow Agro Sciences LLC (2012). Grasses, Revegetation, and Conservation Reserve Program (CRP Guidelines). Techline Online February 2012. Retrieved 1-28-15 from: http://techlinenews.com/articles/2012/12/30/grasses-revegetation-and-crop-reserve-program-guidelines
Pawnee Buttes Seed Inc. (2013). Retrieved on 1-28-15 from: http://www.pawneebuttesseed.com
Goodwin, K., Marks, G., & Sheley, R. (2006). Revegetation Guidelines for Western Montana: Considering Noxious Weeds. Montana State University Extension EB 170. Retrieved on 1-28-15 from:msuextension.org/publications/AgandNaturalResources/EB0170.pdf
Beckworth, L., Daluge, M., Prymak, M., & Ziehl, T. (2015). Teton County Weed & Pest District