For any native garden installation, the first step is to create planting beds. This often means clearing the area of whatever sod, brush, or weeds are growing.

For the fastest results, we at Our Land Organics often use a sod cutter to efficiently clear an area down to bare soil. This process is great for quickly transforming a space. If you have room in your yard, we suggest keeping the removed sod on site to decompose into an excellent compost for future use in your gardens. (This usually takes about a year.)

That said, sod cutting isn’t the only strategy for preparing a new garden bed. For those who aren’t in a rush to plant, sheet mulching and solarization are two excellent options. These methods also help promote overall soil health.

Below, we’ll define solarization and sheet mulching, detail the benefits of each turf destruction method and highlight some things to consider.

Solarization

Put simply, solarization utilizes heat and sunlight to destroy low-growing vegetation, roots, and weed seeds living in a given area. By cutting grass short and covering it with heavy-duty black plastic, you can have a cleared planting bed after one season. 

Benefits of Soil Solarization

DIY-friendly
Solarization doesn’t require specialized equipment or knowledge, and it is a great way for handy homeowners to become involved in their garden project.

Hard on Invasive Species
When utilized for an entire year, solarization with black plastic has been shown to eradicate invasive species such as English ivy and lesser celandine very effectively. Amplify your efforts cutting back weeds low to the ground prior to solarization.

Soil Solarization: Things to Consider

When done properly, solarization can be a very effective method of preparing a planting bed. But there are certain things to be mindful of before electing to solarize a section of your property. 

Time-frame
For best results, solarize the area in question during the hottest months (July, August, September). Keep the area covered for as long as possible.

Depending on the types of vegetation present, solarization could be complete anywhere from one season to one year after the solarization process starts. Tenacious weeds, such as invasive species, might need to be solarized for a full year to prevent grow-back.

Sun Exposure
Solarizing relies on the sun’s energy to cook weeds and roots, so it is not an effective method for heavily shaded, woodland settings.

Water Movement
For sloped or wet areas where water is known to move, solarization can cause water to sheet on top of or beneath the plastic. Depending on what direction water is moving, this can create drainage issues.

Sheet Mulching

Sheet mulching is a process of preparing a garden bed by piling wood chips (with or without a cardboard or newspaper base layer) directly on top of turf, ground cover, or weeds.

When spread thickly enough (6-8” if not using cardboard), the wood chips will smother underlying vegetation. Homeowners can plant directly through the mulch after a period of 3 to 9 months. 

Benefits of Sheet Mulching

Helps Build Soil
While both solarization and sheet mulching can be effective ways to clear a bed, sheet mulching carries with it the added benefit of amending the soil as the wood chips, cardboard, and/or newspaper decompose.

Repurposing Material
Wood chips are an economical way of upcycling unwanted material. Their application can be combined with other projects, such as honeysuckle removal or tree felling.

Same goes for folks who choose to sheet mulch with cardboard or newspaper: you can upcycle an existing product (cardboard boxes or newspaper) and turn it into healthy soil.

Budget-friendly
Wood chips are often freely or cheaply acquired from local arborists, and they offer a free soil amendment as they decompose. Similarly, it’s usually easy to obtain free cardboard by calling big box stores or asking your friends to donate shipping boxes to your project. When done properly, sheet mulching can be a magnificent way to prepare a garden bed on a budget. 

Addressing Common Sheet Mulching Concerns

Nitrogen Absorption
Raw wood chips will absorb nitrogen from the soil, causing concerns of nutrient depletion. In monitored case studies, however, there is no observable negative effect on perennials, shrubs, or trees.

To be safe, you could avoid planting plugs or seeds into raw wood chips, as their nutrient needs are more acute.

Disease/Allelopathic Disturbance
There is no evidence to suggest disease is spread from sick, shredded trees via wood chip mulch. 

Also, the wood chips of trees with allelopathic properties (such as cedar, black locust, or honeysuckle) have shown no observable disturbance to plants mulched with these wood chips in clinical studies.

Termites (Don’t worry!)
Some homeowners worry that using raw wood chips as mulch will attract termites and other pests. In reality, many wood chips actually repel multiple different pests.

If you have additional questions about sheet mulching or solarization, or you’d like some help prepping new garden beds, don’t hesitate to reach out! Our experienced team is happy to assist you with your next project.

Resources and further reading: 

Wood chip mulch

https://ipm.ucanr.edu/PMG/PESTNOTES/pn74145.html

https://extension.colostate.edu/topic-areas/agriculture/soil-solarization-an-alternative-to-soil-fumigants-0-505/