During the heat of summer, place thin clear plastic across any area where you want to kill weeds. Leave the plastic in place for four to six weeks. The sun heats the ground and kills weed roots and seeds, but the intense heat also kills beneficial organisms.
Solarization – a non-chemical way to kill your lawn
Cover your entire lawn with black plastic sheets and weigh down with bricks or rocks. The lawn must stay covered for at least 6 weeks to ensure that it has been properly killed.
It's best to remove as much of the weed growth as possible before laying down black plastic. If the area is mostly composed of annual weeds, such as crabgrass or pigweed, black plastic can effectively kill the weeds and prevent new weed growth.
Plastic Tarp Choice
However, in cooler or coastal areas, black plastic is sometimes better than clear, because weeds won't grow beneath it, as they will under clear plastic when the air temperatures are too low to kill them.
Since it's completely black and free from holes, the plastic sheet blocks the sun completely and traps moisture and air -- the weeds just don't stand a chance.
Use of Plastic in Farming
Black plastic mulch and landscape fabric are also well-known synthetic covers for suppressing weeds, conserving soil moisture, raising soil temperatures, and increasing crop productivity (Kasirajan and Ngouajio, 2012).
Cover it with a plastic tarp, and let the turf sweat to its untimely demise. This takes at least six weeks, which means six weeks of staring at an ugly tarp.
Weed Control 6 mil Black/White Plastic Sheeting
An all-natural alternative to chemical pesticides and herbicides, weed control plastic sheeting kills all weeds and plants covered by the material.
Black sheeting is recommended for applications not exceeding 90 days of sunlight exposure. Special additives are available at request for extended outdoor applications for up to 2 years." Clear plastic sheeting IS RECOMMENDED for greenhouse use and in some cases has a 10 year UV warranty against UV.
Lay down a thick layer of mulch -- at least three inches -- and ensure that all the crabgrass is completely covered. You can also use black plastic, landscape fabric, newspaper, or paver blocks to smother the weeds. If there are other plants or grasses nearby that you want to preserve, make sure they're not covered.
“Weeds germinate in the warm, moist conditions created by the tarp but are then killed by the absence of light.” The tarp also improves the structure of the soil beneath. The heating of the soil does not harm its biological life; the bacteria, fungi and other microscopic soil-improvers are all fine.
If weed killer was still present in the soil, you would not be able to grow anything. This is why most weed killers are designed to evaporate within 24 to 78 hours. This means that for the most part, it is safe to plant anything, edible or non-edible, in a place where you have sprayed weed killer after three days.
You'll usually see weeds curl up and die 7 to 14 days after they're treated. But some weeds take longer to disappear than others. Some tough customers really hang in there — some for as long as a month or longer. Some weeds take multiple applications of weed killer and a couple of months to go away.
A single layer of cardboard is laid out over the areas of lawn no longer needed. When it eventually breaks down, the cardboard will add carbon back into the soil. A crack in the cardboard reveals hardy weeds making their way to the sunlight. Extra mulch will solve this issue.
How Does Mulch Prevent Weeds? Mulch prevents weeds in a number of different ways. New weed seeds need dirt to grow, and a thick layer of mulch helps prevent the seeds from ever reaching the soil. As for the seeds or roots that are already in the soil, mulch blocks one of a plant's essential needs, sunlight.
Rock salt is actually a super-effective and totally natural weed killer that is ace at clearing a gravel driveway. Simply sprinkle some rock salt on the ground surrounding any weeds you can see and then sit back and watch as the salt kills the weeds in just a matter of days. It's almost unbelievable.
Acetic acid is a terrific weed killer but it is also a terrific plant killer! Acetic acid works by drawing all of the moisture out of the weed or plant leaf. It is quick to work and it would be common to see a weed or plant brown up after only a few hours of having vinegar applied to its leaves in the full sun.
Mulch, mulch, mulch
Mulch benefits plants by keeping the soil cool and moist and depriving weeds of light. Organic mulches, in particular, can actually host crickets and carabid beetles, which seek out and devour thousands of weed seeds.
Landscaping plastic is a thin plastic sheeting that smothers weeds through occultation and can benefit soil by retaining moisture. It is a more cost-effective option for weed control and is sold in rolls of varying widths and lengths. This material can benefit your soil by avoiding the need for herbicides.
Landscape fabric has a longer lifespan as it's usually a treated, synthetic material made from polyester or polypropylene. Its composition makes it resist degradation. Black plastic mulch, on the other hand, easily breaks down when exposed to direct heat or sunlight.
Black plastic mulching is only advisable to use for heat-loving vegetables like melons, tomatoes, peppers, and other summer crops. Never use black plastic mulch for growing cool-season crops, such as lettuce, peas, and tubers. Excessive heat will kill these crops.