Solarization or Occultation

Cover weedy or unplanted garden beds with clear plastic (solarization) or black tarps (occultation) for 4-8 weeks during the hottest months. Secure edges with soil, rocks, or sandbags to trap heat and block all light.

Why It Works

Solarization heats soil to 140°F+ in the top 6 inches under clear plastic, killing weed seeds, pathogens, and nematodes. Occultation uses opaque tarps to block all photosynthesis, exhausting weed seedlings that sprout in the dark. Both methods effectively reset the weed seed bank in the top soil layer without chemicals.

Tips

• Use solarization in full-sun areas where daytime temps exceed 80°F for best results
• Occultation works in cooler climates where solarization temperatures are insufficient
• After removing covers, plant immediately without tilling to avoid exposing buried weed seeds