When it comes to preparing a site for a meadow, the age-old mantra “proper preparation prevents poor performance” is worth posting on the refrigerator as the seasons roll by, while you create a suitable environment to seed a carefully considered, site appropriate mix. A well-prepared site demands patience, astute observation, and the ability to adapt. Some things simply cannot be rushed.
Typical meadow preparation involves eliminating the existing vegetation within the project area. The meadow preparation technique or combination of techniques one chooses to employ depends on a variety of factors including site size, budget, available equipment, stakeholder values and site conditions like exposure, soil, moisture, and topography.
Organic meadow preparation forgoes techniques that use conventional herbicide. These methods predominantly include mechanical action, covering or smothering, and/or the use of herbicides made from naturally occurring compounds.
Regardless of the preparation method, it is important to keep in mind the following principles:
1. Vegetation management must incorporate both cool and warm season growth
Just as summer is the best time to grow tomatoes and spring or fall the best time for radishes, different plants (annual, biennial, and perennial) actively grow, flower, and produce seed during different times of the year. It is recommended that existing vegetation on a future meadow site be managed through at least one cool (ideally spring) season and one warm growing season. This is where the patient preparer is rewarded.
2. Vegetation management does not end when the existing cover is eliminated or removed
Cutting short the site preparation stage is perhaps the most common cause of the unsuccessful meadow. A site is cleared of existing vegetation and promptly seeded only for a plethora of weeds to quickly germinate, not allowing the seeded mix to germinate and establish.
When the ground is cleared of vegetation, the dormant seedbank and residual rootstalk fragments within the underlying soil are awakened. On most sites, the ruderal species that quickly colonize the exposed ground are typically considered undesirable (this ability is one of the qualities that makes many weeds so fantastic at being, well, weedy). It is recommended that a site be allowed to express its seed bank and that growth to be managed during the cool and warm seasons.
Unseeded “volunteer” plants will find their way into any newly seeded meadow, and this must be considered in post-seeding management. However, by allowing a site to express its seedbank prior to seeding, the diligent site preparer can reduce the prevalence of early-stage meadow invaders competing with or inhibiting the germination of the desired seeded species.
It is worth noting that, on occasion, sites with limited disturbance histories and surrounding high quality vegetation, the seed bank or natural recruitment from surrounding areas can bring “treasures,” or desirable native species into the meadow. This is where astute observation of site conditions and vegetation is invaluable. Seedling ID guides and plant identification apps, such as iNaturalist, are helpful tools for identifying and evaluating the vegetation within and surrounding the project area.
3. Disturbance can be a tool as well as a pitfall
Disturbance regimes for site preparation like repeated cultivation of the soil can be an effective tool in exhausting a site’s seed bank and existing plant energy reserves and seed bank. After a site is adequately prepared for seeding, disturbance can also stir up dormant plant propagules such as seed or rootstalk fragments and can set back the preparation progress. It is pivotal to limit site disturbance as much as possible prior to, during, and after seeding.
4. Plans change, and that’s ok!
There is no universal recipe to planting a meadow. Every site is unique, and every season has its own idiosyncrasies. While effective site preparation is informed and deliberate, the results of these activities can sometimes be unpredictable. After all, we are dealing with the infinite complexity of nature. A flexible mindset, ability to adapt, and humility when working with nature can alleviate frustration in the face of the unexpected and generate long term success.
Now let’s discuss the different techniques of organic meadow preparation.
Mechanical Site Preparation Techniques
Method 1 – Sod removal
Sod removal, sometimes referred to as “scraping,” is the complete physical removal of a site’s vegetative cover. As the name implies, this is most done when the existing cover is turf, where the spreading, fibrous roots of the grasses form a cohesive layer that can be cut and rolled away. This is an excellent, highly accessible method for converting a small-scale lawn into a wildflower meadow.
Sod removal can be performed at a garden level scale with a sharp spade or “kick style” sod cutter, at a moderate scale with a sod cutting machine, or at a larger scale with the bucket of a tractor or similar machine—having a savvy equipment operator is essential. The intensive nature and bulk of material removed make this method best suited to smaller sites of 1/3 acre or less. Before selecting this method, it is important to consider the fate and means of transporting the removed material. Even a small site can generate a large volume of heavy material. The sheets of sod can be composted (ideally on site) or perhaps incorporated into a hugel mound.
It is important to cut the sod to a depth of at least 2 inches, allowing for the complete removal of the root mass of the existing grass. Sod cut too shallow can leave behind vegetative propagules such as rhizomes or stolons that will readily sprout.
While dense stands of turf can be effective in sealing off the underlying soils to prevent seed spread, that doesn’t mean you are guaranteed a clean slate after removing sod. Monitoring the vegetative colonization of an area after sod removal is essential to determining the timing and methods for the remainder of site preparation. Additionally, evaluating the surrounding vegetation is helpful in making educated predictions as to what may repopulate the area (both in the short and long term) if left to its own devices.
Often, what is hiding beneath the turfgrass are typical turfgrass weeds such as Plantago sp. (Plantain), Trifolium sp. and Glechoma hederacea (Ground Ivy), and Digitaria sp. (Crabgrass). After sod removal, it’s prudent to allow the underlying seed bank to express itself through both a warm and cool period. Awakened vegetation can be managed through additional site scraping, spot scraping (a great hand tool for this is the “stirrup” hoe), scalp mowing, or an organic herbicide, flame, or steam application timed when seedlings are small and vulnerable, prior to seeding.
Method 2 – Repeated Cultivation
Repeated cultivation harnesses the power of site disturbance. This method can be scaled to large areas and is effective on sites with a history of agriculture. By repeatedly uprooting existing plants, through shallow cultivation, existing vegetation and the seed bank can be effectively exhausted prior to seeding. It is important that cultivation remain at a shallow, consistent depth (2 inches is ideal) as to not stir up additional weed seeds. Cultivation occurs at intervals throughout the growing season (ideally when growth reaches 3-5 inches) until signs of an exhausted vegetation cover and seed bank appear.
Identifying existing vegetation prior to cultivating is essential. If undesirable rhizomatous perennials such as Artemisia vulgaris (Mugwort) Cirsium arvense (Creeping Thistle), or Phalaris arundinacea (Reed Canary Grass) are present, cultivation can have the undesired effect of assisting in propagating these plants through the division and distribution of their rhizomes. If substantial populations of these plants are present, repeated cultivation may not be the preferred technique for site preparation or may need to be altered (increased cultivation depth, extended timeline) to prove effective in exhaustion and suppression. Mugwort rhizomes have been shown to penetrate soil depths of up to 8 inches and fragments smaller than a fingernail can root and re-sprout.
Some drawbacks to repeated cultivation are that it requires consistent access to large equipment, it isn’t effective on wet, sloped, or rocky sites and can temporarily affect soil structure.
Smothering
As with many of these methods, smothering or “cooking” to eliminate undesired vegetation has its roots in organic agriculture practices. In meadow preparation, these techniques are typically employed on smaller sites (less than half an acre).
It is worth noting that these techniques are materially intensive, costly, may be considered an eyesore, and require a significant amount of plastic. The material can be reused but eventually will require responsible disposal (experience has shown that this material cannot be industrially recycled, however that may eventually change or depend on locality). It is most ideal if materials are already on-hand, can be found and repurposed locally or can be reused on-site for multiple seasons.
Method 1 – Tarping
Smothering with dedicated silage tarps or general-purpose tarps can be effective in germinating weed seeds and starving plants’ access to light. What this technique may not effectively manage, however, are perennial plants with the ability to go dormant and subsist off the energy stored in their root mass. To exhaust these species, the tarps may need to cover the area for multiple growing seasons. Therefore, smothering alone is typically not recommended as a stand-alone strategy for site preparation, but it can be useful to smother an area with little weed pressure or to cover a site adequately prepared by other means until seeding can be performed.
Method 2 – Solarization
Solarization—covering an area with clear or black plastic with the goal of “cooking” the underlying vegetation—can be a highly effective technique in preparing a meadow. Clear, UV resistant 4-6mil plastic has shown to be most efficient in heating the soil to temperatures upward of 145 degrees Fahrenheit, destroying plant tissue and weed seeds in the soil, much like an industrial composting system. This technique is best suited for flat or gently sloped sites in full sun that are not particularly wet, rocky, or full of microvariations in topography.
To reach and sustain adequate temperatures, the site must be sufficiently prepared, and the surface should be as even as possible. Existing vegetation is cut, debris and other objects capable of puncturing the plastic removed, and the area thoroughly watered. When installing the plastic, aim to stretch it as taught and close to the surface as possible. Digging a trench and burying the edges of the plastic is an effective securement method. For larger sites, a trenching machine is invaluable. If possible, the trenches can remain after the plastic is removed to act as an “air gap,” preventing invasion from surrounding rhizomatous and stoloniferous plants.
This method has been shown to be effective in eliminating particularly pernicious plants such as mugwort, but the effect of solar radiation has a limited ability to penetrate the soil. Plants with particularly deep rhizomes like field Convolvulus arvensis (Bindweed) or tubers such as yellow Cyperus esculentus (Nutsedge) are not sufficiently controlled as the heat is unable to penetrate to adequate soil depths.
Once the plastic is installed, in most cases it should remain over the area for at least one entire growing season and only be removed immediately prior to seeding. The material can tear easily, particularly when walked on (curious deer are particularly skilled at turning the covering into Swiss cheese) so additional plastic and repair tape should be kept on hand. When the plastic is removed, care should be taken to limit the resulting disturbance. Stirring things up can bring undesired seeds and other plant propagules to the surface, negating hard-won progress.
While solarization has been used to control soilborne diseases in agricultural crops, the heating effects can also negatively impact beneficial soil biology. Additional research on this subject is required but this is something to be considered. On small scales, biota can be introduced via organic amendments. Limiting disturbance, establishing native plant communities, and allowing organic matter such as the previous year’s meadow clippings to remain on site will encourage the development of a healthy soil ecosystem over time.
Organic Herbicide
Organic herbicides can contain naturally derived ingredients (e.g., soaps, acids, oils) that all act as “contact herbicides.” This means that they only affect plant tissue that they come into direct contact with. In contrast, traditional herbicides work systemically, and are taken up and translocated within the plant. This means that to be effective, organic herbicides must be sprayed onto the entire surface of the plant, typically require multiple applications, and have limitations, particularly in controlling and established perennials (especially fine-leaved grasses) and woody plants.
These products are particularly effective in controlling seedlings and shallow-rooted annual plants. When applied to perennial plants, they will burn off the foliage but the plants will typically resprout, necessitating multiple, properly timed applications to adequately deplete the plant’s energy reserves. Organic herbicides are best applied when growth is small (ideally 4-6”) so it is best to mow 2-3 weeks prior to treatment or start treatments in the spring as growth begins.
Experience has shown that adequate preparation of a site with light to moderate weed pressure requires five broadcast applications of organic herbicides throughout a growing season. When applications are performed each time most of the vegetation in the area reaches a height of 4-6 inches. In the year following a seeding, residual undesirable perennials were observed—in this case spotted knapweed (Centaurea stoebe) and couch grass (Elymus repens)—and required additional treatments.
The effects of organic herbicides can be comparable to that of flame or steam weeders, as impact on the plant tissue is similar. Organic products are touted as “nontoxic” alternatives to conventional herbicides and typically have a much shorter residual presence after application, but it is worth noting that the acute effects of these products—to oneself and the surrounding environment—should be considered. Acetic acid, also known as horticultural vinegar, in concentrations over 11% (at least 20% is recommended as an effective herbicide) can burn the skin, cause severe eye injury, and prolonged exposure can have respiratory effects.
When considering the use of any herbicide, organic or otherwise, it is important to read the label and understand the product’s health and safety guidelines as well as the environmental impacts. Many organic herbicides are registered with the Environmental Protection Agency and are best applied by a certified applicator following best practices.
The methods described above are by no means the only strategies for organic meadow preparation. Other site preparation techniques include:
- Soil inversion – Using a plow to bury existing vegetation and seeds
- Sheet mulching – Using layers of organic material to smother existing vegetation
- Smother cropping – Using cover crops to smother and outcompete existing vegetation
- Soil removal – Excavating and removing the top layers of soil from an area
There is no one-size-fits-all method of meadow preparation. Organic preparation strategies can be highly effective but must be employed appropriately and thoughtfully. Converting a site into a native meadow is a challenging, exciting, and deeply rewarding process that will bring you closer to the land and perhaps inspire others. One does not need to be an expert to prepare and plant a meadow, but patience, observation, and informed decision-making go a long way. Firsthand familiarity with these methods is invaluable and further testing and experimentation is highly encouraged.
Every site is different and preparation techniques need to be weighed in relation to site limitations, stakeholder values, budget, and environmental impacts. It is easy to feel daunted or fall into a rut of “analysis paralysis” and forgo any action whatsoever due to a fear of an unsuccessful meadow. An open, flexible mindset along with strategies like a cautious preparation timeline, preparing and seeding a test plot before tackling a large site and consulting a local professional can be helpful in starting with your best foot forward.