kill weeds with sunshine
Solarization
Solarization is a process that uses the sun’s power to heat the soil to high temperatures that kill a wide range of soil-borne pests, including weeds, pathogens, nematodes, and insect pests. This is a non-chemical method and can be very effective.
Gardening guide
Use solarization instead of a herbicide
Prepare the Soil
Start by preparing the area where you intend to solarize. Remove any existing plants or weeds. Then till the soil about 6 to 8 inches deep to break up large clumps and make it uniformly fine. This will ensure that the heat can penetrate more effectively.
Water the Soil
Thoroughly water the area you’re going to solarize. This is a key step because moist soil can conduct heat more effectively than dry soil. The soil should be wet, but not waterlogged.
Cover the Soil
Cover the prepared and watered area with a clear plastic tarp. The thickness should be around 1 to 6 mils, but remember, the thicker the plastic, the longer it will take for the heat to penetrate. Secure the edges of the plastic by burying them in the soil, using rocks, bricks, or soil staples to keep it in place.
Harness the power of the sun
Leave the plastic cover on for at least 4 to 6 weeks during the hottest part of the year. The goal is to let the sun heat the soil to a depth of about 12 to 18 inches and maintain that heat. The soil temperature needs to reach 110 to 125°F (43 to 52°C) for optimum effectiveness.
Remove the Plastic
After 4 to 6 weeks, remove the plastic tarp. If possible, leave the soil undisturbed for a week or so to allow the heat to kill any remaining pests.
Re-plant
Once you’re done, you can plant in the soil. The solarization process should have killed many soil pests, giving your plants a healthy start.
Keep in mind that while solarization is effective at controlling many types of weeds, it may not be fully effective against all types, especially those that have deep root systems or produce a large number of seeds that remain viable in the soil for many years. Additionally, beneficial soil organisms and nutrients can also be affected by solarization, so it’s not a practice to be overused. It is generally a good practice to reintroduce beneficial microorganisms by adding compost or other organic matter after solarization.