Easy Way to Kill Grass and Weeds With Tarp or Weed Blocker
Quick facts
- Solarization is the process of placing a clear plastic tarp over an surface area to rut upward the soil underneath.
- Occultation uses opaque coverings instead of articulate. Occultation takes longer.
- The plastic traps heat and moisture, which encourages seed germination and plant growth.
- Past blocking access to h2o and heating up the soil, the procedure eventually kills the vegetation underneath.
Late summer is a great time to set up garden infinite to commencement a new garden or bee lawn. Solarization and occultation are simple methods to remove existing vegetation and get alee of weeds.
What is solarization?
Solarization is the process of placing a clear plastic tarp over a field, garden bed or lawn to estrus up the soil underneath. The intention of solarization is to kill weeds or grass, though it tin have added benefits of reducing pathogen populations in the soil.
The plastic covering produces a greenhouse result:
- The plastic traps heat and moisture, which encourages seed germination and establish growth.
- Past blocking access to water and heating upward the soil, the solarization process eventually kills the vegetation underneath.
Clear plastic tarps from your local hardware store (2-6 mil) are sufficient for polarization. The process typically takes around ii to 3 weeks during hot summer months. The procedure is complete when the vegetation underneath the tarp is dead.
What is occultation?
Occultation is like to solarization, only opaque coverings are used instead of articulate. While it may audio counterintuitive, fields covered in clear plastic get hotter than fields covered in black plastic.
Black plastic actually absorbs lite, whereas clear plastic allows low-cal and heat to pass through. So occultation takes longer.
Occultation typically requires at to the lowest degree four weeks to exist effective. The longer you continue the roofing in identify, the more effective it will be, up to about six weeks, at which point efficacy begins to level off.
Mutual materials for occultation on a small scale include common tarps and paper-thin. On a larger scale, you can use silage tarps and old billboards. Since these materials tend to be relatively heavy, you can use sandbags, bricks or other heavy objects to weigh downward the edges.
Why choose occultation over solarization?
While occultation takes longer, there are a few benefits.
- The types of tarps used in occultation tend to be re-usable.
- Solarization tarps are thin and more prone to tears.
- Because opaque tarps are multi-functional, you may already have some at dwelling.
New fields and lawns
If you're using solarization and occultation to outset a new garden in a space with grass or other vegetation, there are two approaches.
- The starting time is to till the soil start, and then add the tarp to suppress weed seeds brought to the surface through cultivation likewise as remaining grass.
- The second is to employ the tarp to kill the grass. Mow the grass as curt as possible before adding your tarp.
Tilling prior to solarizing or using occultation will speed up the process and can accept the added benefit of aerating soil that has been compacted.
Existing beds: fix the seedbed
Solarization and occultation can be used for weed management at whatsoever point in the flavour (most often in the spring) in existing garden beds and fields. These strategies allow you lot to eliminate the get-go flush of weed seeds before planting vegetables and flowers.
In guild for weed weeds to germinate, they need warmth, skilful seed to soil contact, wet and, in some cases, light. By preparing a seedbed prior to solarizing or using occultation, you lot increment the likelihood that weed seeds will germinate under your tarps compared to a field that has non been prepared.
To set the seedbed:
- Aerate meaty soil with a tool such every bit a broadfork or a pitchfork.
- Work in compost, manure or other fertilizers.
- Smoothen the soil surface with a tilther or a rake.
- H2o the soil before covering with the tarp.
Water
Moisture is a cardinal ingredient for weed seed germination, so watering before installing your tarps volition improve functioning. Water until the soil is moist down to about 12 inches before adding tarps.
One key principle of solarization and occultation is preventing water from reaching the soil afterward the initial irrigation. So these methods will be less effective in low spots that receive meaning drainage, and where water can enter underneath the tarp from the edges.
Staking tarps
Tarps blow away easily and need to exist held down.
- For solarization, it's best to bury the edges to class a tight seal.
- If this is not possible, you tin apply mural staples to hold the edges downwardly, simply have care to avoid tearing the plastic.
- You can counterbalance down the tarp with bricks or sandbags on the corners for actress back up, especially in very windy areas.
- For heavier tarps, placing heavy objects around the edges and beyond the elevation should be sufficient.
Soil wellness impacts
Heating the soil tin can have significant impacts on soil biology, only these changes are not necessarily negative. At that place are few studies virtually the long-term impacts of soil solarization on microbial communities, simply it is an emerging expanse of enquiry.
Ane contempo study of solarization and its impacts on microbial communities reported a decrease in overall species richness and abundance (Kanaan et al., 2018), and another reported a subtract in soil microbial activity later on solarization (Smith et al., 2017). Yet, the Kanaan study showed increased yields in both wheat and eggplant following soil solarization.
Every bit this topic becomes more ordinarily studied, we will learn more than about the longer-term impacts of these practices.
Housam Kanaan, H., S. Frenk, M. Raviv, S. Medina, D. Minz. Long and short term effects of solarization on soil microbiome and agricultural production. 2018. Applied Soil Ecology, 124: 54-61.
Smith, Grace, Sonja Birthisel, Eric R. Gallandt. Comparing Solarization & Occultation. 2017. University of Maine.
Reviewed in 2021
Source: https://extension.umn.edu/planting-and-growing-guides/solarization-occultation