If you've ever looked at a patch of weeds in your garden and wished for a natural, no-chemical solution — you're not alone. Luckily, there’s a gentle, earth-friendly method that’s gaining popularity among home gardeners and farmers alike: occultation.
Also known as tarping, this technique is a DIY weed killer that works (with a few exceptions; looking at you nut grass) by using opaque tarps to block sunlight, which in turn weakens and kills unwanted weeds. It’s simple, sustainable, and one of the best ways to reduce weed pressure without harming your soil or using chemicals.
What Is Occultation?
Occultation involves covering your garden beds with dark, opaque tarps for several weeks. The tarps prevent sunlight from reaching the soil, which stops weeds and seeds from growing. Eventually, the weeds die off. Tougher varieties like nut grass weeds, unfortunately, still need human powered hands.
You can use everything from black silage tarps to repurposed billboard signs (a great way to recycle!). After several weeks under the tarp, most of the weeds are gone, and the garden is ready for another round of planting — naturally.
Why We Love It on the Farm
We do not use chemical fertilizers or pesticides and instead use more hands-on, sustainable methods. Occultation fits right in. It allows us to control weeds and prepare beds naturally, while also keeping our soil healthy and intact.
Of course, we also pull plenty of weeds by hand (it’s kind of a team sport around here), but occultation helps reduce the time and effort we spend on repeat weed battles. It’s become a core part of our approach to what we consider one of the best natural weed killer strategies that we know of.
How to Use Occultation as a DIY Weed Killer
If you're looking for a DIY weed killer that works, here’s a simple way to get started:
- After harvesting, mow down the leftover plants and clean up the garden bed.
- Cover the area with a heavy-duty, opaque tarp. Black plastic, silage tarps, or old billboard signs work well.
- Secure the edges using soil, bricks, or sandbags to keep the tarp from blowing away.
- Let it sit for 4 to 8 weeks. During this time, sunlight is blocked, and weeds start to break down.
Remove the tarp and check the bed. If it looks mostly weed-free, you’re ready to prepare the soil and plant again!
Benefits of Occultation:
- Acts as a DIY weed killer without any harmful chemicals
- Protects soil structure — no tilling required
- Speeds up decomposition of plant residue
- Reduces long-term weed pressure over time
A Few Considerations:
- Some deep-rooted weeds may still survive and need to be removed manually
- It’s important to secure tarps well to prevent wind from lifting them
- Occultation takes a few weeks to work, so it’s not a quick fix — but it’s a lasting one
Whether you're a backyard gardener or working a larger plot, occultation is one of the best natural weed killer methods we’ve found. It’s easy, cost-effective, and safe for the environment, your soil and your plants.
We’re always on the lookout for more DIY weed killer techniques. Got a favorite method you love to use in your garden? Let us know — we’d love to hear from fellow growers!