The importance of site-preparation cannot be overstated. Before planting, you will need to eliminate existing undesirable vegetation, eradicate weeds, remove plant debris, and ensure you have a clean surface that will facilitate good seed to soil contact or be cleared for using transplants.
Site preparation techniques may vary depending on the size of your project, and must take into account many factors: Cost and availability of resources, speed at which you want to establish your new plantings, and impacts on the environment to name a few. Another consideration is how these plantings will be maintained over time. Meadows and other pollinator plantings can be low-maintenance, but are rarely if ever maintenance free. Future maintenance and management should also be considered prior to installation.
Use of Herbicides
The application of post-emergent herbicides containing glyphosate as their active ingredient is low-cost and requires minimal labor, making this a frequently used option for site preparation. However, to reduce the environmental impact of herbicides, they should be used judiciously, or as a supplement to other site preparation methods. For maximum efficacy, herbicides should be applied when plants are actively growing. Typically, they are most effective on plants such as grasses, just as those plant develop flower stalks, in the time leading up to flower development.
Anyone applying herbicides should read all instructions fully, dilute product to manufacturer’s specifications, and only apply on still days without wind to avoid drift. Note that special licensing is required to be apply herbicides near ponds, streams, or other bodies of water, and for aquatic weed situations, it is recommended to seek out the support of professional, licensed habitat restoration specialists.
Tilling or cultivation should be avoided as part of any site-preparation strategy. Tilling kills ground nesting insects and brings weed seeds to the surface where they will germinate and negatively impact wildflower establishment. Additionally, repeated cultivation damages soil structure, speeds erosion, and releases carbon dioxide into the environment.
Smothering and Solarizing
For gardens or smaller plantings (1000sf or less) smothering is an ideal, chemical free site preparation method. Prior to the active growing season, cover the area completely with cardboard or a heavy layer of newspaper - overlapping this material to ensure the entire area is covered. Then cover the material with compost, leaves, yard trimmings, or other material that will naturally break down. Allow the site to smother for an entire growing season before planting for best results.
Similar to smothering, solarizing is our preferred method of organic site preparation and has proven to be more than 90% effective at eradicating existing weeds. As with smothering, the entire area is covered in clear plastic prior to a growing season (this can be done in fall or winter where the ground is workable.) Edges of the plastic are buried to keep the plastic in place and to keep heat in. By trapping heat and limiting oxygen and room to grow, unwanted vegetation is smothered. This method is effective at killing annual, perennial, and biennial weed species without herbicides. For more information, please review the resources below.