What is the Cheapest Way to Kill Grass?

Lawns are a national obsession in the United States and Canada, but more and more, we’re realizing just what a drain these fertilizer and herbicide-treated lawns are, in both environmental costs and in our own free time and money.

The cheapest way to kill grass is through cardboard sheet mulching. You can pick up old cardboard boxes for free from appliance and furniture stores (or save up packages). By covering up the grass, you remove its access to sunlight, which it needs to live. After a few weeks or months, it’ll die off completely and compost. This method is organic and natural.

Why Kill Your Grass?

There are many reasons why you may want to kill your grass:

  • Fend off creeping rhizomatic grass. Grass, especially rhizomatic grass, has a habit of spreading far beyond your lawn, infiltrating patios, sidewalks, and garden beds.
  • Grow food instead of grass. The COVID-19 pandemic showed us just how fragile the food distribution system is and how close to food insecurity we are. We can’t eat grass, but your front and backyard could grow fruits and vegetables. Even if you only have a little space, growing some food brings you closer to the natural rhythm and motivates you to make sustainable decisions.
  • Encourage biodiversity. Most lawns are monocrops that lack the variety of plants needed to support other creatures like bees, butterflies, beneficial insects, and birds. By getting rid of your lawn (or part of your lawn) and growing pollinator-friendly flowers, you’re helping these little critters survive, bringing delight to your backyard, and helping the planet.
  • Reduce water usage. Lawns are thirsty plants and ill-suited to a lot of places in North America. By removing or replacing your non-native lawn, you’ll find more freedom under drought restrictions and save a ton of money on your water bill too.
  • Reduce yard care and maintenance. Lawns can take a lot of time to keep looking presentable, especially non-native species that aren’t suited to your climate, and most people don’t even use most of their existing lawn. By replacing your grass with a native species, replacing it with a low-maintenance garden, or using artificial turf, you can save your weekends.
  • Start over from scratch. You don’t want to give up your lawn, but for one of many reasons, your lawn is not serving your needs. You can remove the existing lawn and replace it with something that fits your goals and your climate (and can even benefit pollinators too!).

5 Cheapest Ways to Kill Your Grass

So you’ve decided that the lawn (or part of it) has to go. How can you do that without dropping a bunch of cash?

1. Cardboard Sheet Mulching

cardboard sheet mulching

Sheet mulching is a cheap and natural way to remove all plant matter from an area by arranging a layer of cardboard over the grass. Grass needs sun to grow, and if it doesn’t have sun, it dies off. After a few months, the cardboard itself will decompose and add carbon to the soil, while the dead grass will decompose too into vital nutrients that will give your next lawn or garden a head start.

The bigger the cardboard, the better, but you don’t need to buy a ton of moving boxes from the local U-Haul. Some U-Haul locations have a free used box section you can take, its best to ask first. Appliance and furniture stores are inundated with large cardboard boxes — just ask them for some. Often you can find people giving away moving boxes on the Facebook Marketplace too!

The main drawback is that this process takes weeks, or even months, so you’ll need to plan ahead of time or be patient.

2. Solarizing

Like cardboard sheet mulching, solarization involves covering the unwanted grass, but this time with a clear plastic sheet. The sun shines through the sheet, heating the grass and top layer of soil to boiling temperatures. The grass dies and decomposes back into the soil.

Solarization works a lot faster than cardboard sheet mulching, but it’s only effective in summer when days are long and ambient temperatures are already high. Outside of this time, it’s better to use sheet mulching. You also will still have the plastic tarp leftover.

3. Boiling Water

boil water kill grass

Boiling water works much like solarization by heating plants past the point of survival. The boiling water will even sink down into the soil to kill weed tap roots and ungerminated seeds. Just like solarization, boiling water will kill everything in its path. Depending on how hardy your grass is, it may take a few applications. Some people recommend adding salt, but that will make it harder to regrow a new lawn or garden.

The disadvantage of this method is that while killing a small patch of grass is easy, you have to boil a LOT of water to take care of larger areas. It’s also more dangerous for you, as it’s easy to burn yourself accidentally, either from splashing water or from trying to pour out of a pot. Wear pants, long sleeves, and closed-toe shoes to protect your skin. When possible, use a kettle.

4. Employ Chickens

If you’re planning on raising chickens as part of your backyard renovation, then you can, um, get two birds with one stone. Chickens love eating and digging at grass, and they’ll end up eating weed seeds and fertilizing the soil to boot. This method will take a much longer time (up to three years), depending on how much grass you need removed, but you can’t argue with the results.

5. Double Digging

In a hurry to remove the lawn? Skip your CrossFit and double dig your lawn. All you need is a flat-edged shovel and a will for heavy-duty labour. Cut through the turf with the sharp edge of the shovel in a shovel-sized square, then cut beneath it until you can get it up and flip it over into the previous patch. The grass side should end up on the bottom with the soil side exposed. The grass will decompose and feed the soil. Check out our complete guide to double digging for more info.

Renting a tiller will cut down on labour, but is a more expensive option. If your grass species is invasive and can grow back from rhizomes, then compost it and lay a [new layer of compost/topsoil instead.

The Importance of Going with Natural Methods

Spraying Roundup may seem like an easy method, but applying chemicals often comes with unforeseen negative consequences. Herbicides could end up drifting onto your beloved garden plants and killing them, or draining off into the groundwater where they then build up and wreak havoc on local fish, animals, and plants. They’re also dangerous to your health!

Besides the unexpected environmental costs, herbicides are expensive! That money is much better spent on picking a high-quality lawn replacement or starting your new garden.

Can I Grow Grass Again If I Change My Mind?

If you use an all-natural method that doesn’t introduce any new chemicals (including salt), then you can regrow your grass again. Before jumping in, make sure that you know why you want the grass and what you’re going to use it for, then look for native grasses that can handle those goals while needing the least amount of chemicals and care. A bit of forethought will save you a lot of time tearing it out again.

Final Thoughts

You don’t need to spend a lot of money or spray a ton of toxic chemicals in order to effectively kill grass. You can shade it through cardboard sheet mulching or double digging, or boil it alive with solarisation and boiling water. Or even let your backyard chickens go wild. The method you choose will depend on the time frame you have and what’s at your disposal, with double digging and boiling water taking the least time and cardboard sheet mulching taking the most.

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