Following an establishment plan
To maximize your investment in seed, follow the establishment plan to get the best chance of success. These timelines are guidelines. Weather and individual situations can change the process and the dates mentioned are only recommendations.
During establishment and for the life of a native planting, always consider the movement of seed with vehicles and equipment. We recommend you blow down or wash off equipment and vehicles before entering the field, especially if the equipment/vehicle was recently used in a field ripe with seed of a species you do not want in your native planting (e.g. fescue, sericea, Johnsongrass).
Choose the best timeline
If you’re not sure this is the right establishment plan for your situation, use our Planting Timeline Selector or read the Establishment Plans Overview.
Establishing natives without herbicide
Using herbicides to establish native plants is the most widely practiced and is very effective. Some herbicides also speed up the establishment process of native plants. However, if you are wanting to avoid the use of herbicide, there are several ways to go about the process.
Choosing the best method
Some non-herbicide establishment methods have been shown to work well such as removing topsoil and some methods are not well proven such as using plastic or stress and smother. Though well-proven, removing topsoil can be a big expense on a large area. Likewise, using plastic may not be realistic on a larger area. On the other hand, the stress and smother method can be very feasible on a larger area.
If you are going to try the plastic method or stress and smother method, understand the principles, be a good observer, and understand what is happening to have a successful establishment. The most important steps behind a successful establishment are to make sure that all the mother plants of the weed species are killed, then the seedlings that emerge need to be killed for at least another year.
Removing topsoil will allow you to get rid of weed seeds that are in the top inches of the soil. This process occurs naturally during a pond dam construction or during new construction where the topsoil is removed.
Do not bring in topsoil from somewhere else because it will contain seeds of what was planted in it. See the New Dirt Work Guide for more information on new dirt work.
Studies have been done in Australia show that removing topsoil can be a very effective way to eliminate weeds from coming back in a planting. They removed, or “scalped,” four inches of topsoil from an area with a road grader and used herbicide for three consecutive years on another area. They found there was a greater abundance of native plants emerging on the scalped area than the area that was treated with herbicide. Removing topsoil also removes nutrients that aid weeds in growing and out competing native species.
Stress and smother
The stress and smother method uses tools such as mowing, grazing, plowing, and/or prescribed burning to stress unwanted species, while cover crops are used to smother them, causing them to compete for resources such as sunlight, water, and nutrients.
Because there is no cut-and-dry recipe, it is very important to be able to identify the unwanted species and know its active growing seasons and observe if the weeds are being killed.
An example of this method on an existing fescue pasture would be to graze, mow, or burn the area low in mid-April, then graze or mow again in two weeks, and repeat the grazing or mowing again in two more weeks.
Stressing the perennial species will allow the planting of a diverse mix of summer annual cover crops to become established. The cover crop could then be removed in August by grazing, plowing, or mowing.
The fescue will actively begin growing once again and its seedlings will be encouraged to germinate with the cooler temperatures and moisture from fall rains, so planting another diverse cover crop in early September would compete with and continue to smother the fescue.
This process of stressing and smothering will need to be repeated in the future. Stress and smother can take many years to control the unwanted species before it is time to plant the natives. Before planting, make sure that all the mother plants and seedlings have been eradicated. This means that after the last plant is killed, keep at it for at least one more year so that seeds in the seedbank are encouraged to germinate and are stressed to the point of death as well.
Stress and smother is a very diligent method and must be done in a timely manner. Remember, establishment results will only be as good as the success of the weed control.
Tips for cover crops
- Provide as much competition as possible by planting a diversity of cover crops that come on quickly and grow to be large plants.
- Avoid using clovers, vetches and other species that have hard seed coats or long dormancy periods, as well as species that tend to re-seed themselves readily in your cover crop mixes.
- Do not let any of the cover crops go to seed. If they are starting to go to seed, graze, harvest, or mow them immediately.
- Some excellent cover crop to plant in summer: Sorghum Sudangrass (This species is allelopathic, so it may inhibit establishment of the fall-planted cover crops.), Pearl Millet, Soybeans, Buckwheat, and Cowpeas
- Excellent cover crops to plant in fall: Spring Oats, Turnips, Tillage Radishes (also called Daikon Radish), and Rape
- Planting a warm season cover crop such as Millet or Buckwheat that is quick to establish will give a smother crop in the last days of summer while the cool season component is getting established and going.
- Cover crop seeding rates may need to be increased to get a dense stand to smother out the existing vegetation.
- Fertilizing the cover crops can also be beneficial to give the cover crops a quicker growth rate, and they may grow larger.
- Do not plow Bermuda or Johnson grass since they have rhizomonous root systems. Plowing can break up and spread the rhizomes causing a larger infestation of Bermuda or Johnson grass.
- If the existing vegetation is a warm season grass, stressing may need to be done a year in advance before planting a cover crop.
- If the cover crop seeding is not a successful stand, stressing events will still need to take place or the area will need to be reseeded with cover crops so as not to lose any progress that has been made.
This method can be effective to specifically kill annual weeds. This can be achieved by laying plastic on top of the existing vegetation. Logs, rocks, or any other heavy objects will be needed to hold the plastic down so that the plastic stays on the ground.
Depending on the species and the air temperature it can take anywhere from a week to months to kill annual weeds. Perennials will take considerably longer. It is very important to know how to identify the plant species in your area, so you know how to evaluate the progress of eradicating the unwanted vegetation.
Once you have removed the plastic, hand weed to pull out any isolated plants that have deep root systems.
A cover crop could be planted after the plastic is removed to add competition to weeds that may still germinate. This method could take a long time to kill perennial weed species. Remember to keep in mind that the goal is to first kill all the mother plants, then spend the next entire growing season killing any seedlings that emerge.
If the aesthetics of plastic are unwanted, consider sheet composting, also called lasagna gardening. However, make sure to achieve seed-to-soil contact when planting in a lasagna garden. Most importantly, make sure to kill all of the unwanted perennial plants.