Easiest way to get rid of lawn

October 4, 2021 10:34 AM

Just a simple question: I want to kill my lawn, and avoid doing the difficult work of using a sod cutter (like I did with a large section this year). So, can I successfully kill my lawn by laying down landscaping fabric now and leaving it there until Spring?

I'm in Northern-ish Canada and we'll have snow covering everything from about November/December until March/April. If I attempt the landscape fabric, will I just end up having to go at the remaining sod/thatch/ with a sod cutter anyways?

Note: My plan is not to put down the fabric and build soil on top of it. I have way too much land for that to be an effective solution. I would lay down the fabric now, and remove and dispose of it in the Spring.

posted by kitcat to Home & Garden (25 answers total)

I tried to kill off strip of lawn by covering it with black plastic for several weeks during a summer. It did nothing. My next door neighbors had their front lawn replaced and the people who did it sprayed the whole thing down with Roundup, and that took care of it in about a week.

I know Roundup is disliked for a variety of reasons, but it definitely works.
posted by jonathanhughes at 10:39 AM on October 4, 2021

The standard method is to cover it with a thick layer of cardboard (or many layers of newspaper) and then put a bit of mulch and leaves on top.

Do that ASAP, and when spring comes you plant (preferably native plants) by cutting small holes.

Over the next year, the stuff composts in place and your desirable plants keep the grass down.

If your scale is too large or you don't want to wait long enough to do it in pieces, glyphosate is what professional conservation and restoration experts use. It is safe and effective when used as directed.

Your plan will not work; established turf grass and weeds won't mind that much at all.

Sod cutting is also not great, it damages your soil community and fertility, abs also costs plenty of money and time.
posted by SaltySalticid at 10:44 AM on October 4, 2021 [9 favorites]

I put down blue tarp for about a month of a Canadian spring, trying to kill a grass lawn to replace with clover. It did kill most of the grass but the dandelions, plantains, and prickly weeds flourished under the tarp. Tarp is a bit translucent so they had a dim light source- so with black fabric you may have more success.

But I think the real learning was that weeds with tap roots are hardy and hard to kill. I don't know if my grass was totally knocked out by the tarp because I then helped kill it further by adding top soil and tilling up the whole yard to enrich and level the soil, then I seeded grass and clover.

What's your plan to replace the grass? You probably want to have your replacement plan ready to go, to crowd the weeds out as soon as most of the grass is dead, or else the weeds you already have will get stronger, and new ones will quickly move in.
posted by nouvelle-personne at 10:48 AM on October 4, 2021 [2 favorites]

It's used to being covered all winter by snow, so I don't expect you'll be successful with this strategy.
posted by flimflam at 10:58 AM on October 4, 2021 [2 favorites]

Response by poster: If it matters, my plan is to plant flowers in some spots, vegetables in other, microclover in others. I have a huge corner lot, and I'm only concentrating on the front lawn for now. This is a multi-year task.

I did about a 10 X 15 foot spot this year and put in a beautiful garden. The process was:

1. Use sod cutter, remove sod
2. Use shovel to get rid of as many dandelions, thistles, plantains as possible
3. Add maybe 3 inches of soil
4. Till everything

Putting mulch and soil over to create at least 15 inches over such a a large area will cost...I don't even want to know. Many truckloads. Probably close to 1K. Should I really do that? They say you shouldn't even plant on top of landscaping fabric anyhow, it's just a terrible idea all around.

So I'll use the sod cutter again if I have to. It's just very hard labor (both the cutting, and the rolling and hauling off the sod).

nouvelle-personne - so after you removed the tarp in the Spring, were you able to dig in with a shovel to get at those weeds and till everything? You didn't have a thick layer of dead grass/thatch to remove? There's no reason I can't use tarps myself. Except that..I guess landscape fabric is socially acceptable, while I'm sure I'll get bylaw called on me if I use blue tarps.
posted by kitcat at 11:48 AM on October 4, 2021

I would mow it as short as possible now and keep it short until winter sets in. In early spring, as soon as you see the grass start to green, mow it short once more and then hit it with the black plastic. I picture landscape fabric as sheer but the plastic I mean is not. It should be at least 6 mil. Keep it on the ground all spring, summer and fall 2022.

Then again in spring 2023 lay the plastic down when the area starts to green. This time just for a couple weeks to kill off anything sprouting.

Then late spring 2023, remove the plastic for good and start implementing your replanting plan. I agree with others you need to know what you want to do after killing the lawn. That's really probably the most important point.

& Mulch is your friend!
posted by Press Butt.on to Check at 12:01 PM on October 4, 2021

"Sheet mulch" is the name for the cardboard plus wood chips method. It is relatively effective, and now is a good time to do it. Google insturctions for it. 15 inches is way more mulch than needed, cardboard plus 3-6 inches of chips is plenty. See if chipdrop is available in your area; if not, you can likely still call local arborists to get free wood chips delivered to your house.

Some hardy grasses like bermuda grass will have partial survival of sheet mulching. Killing them ahead of time reduces your weeding workload later. If you were starting this in spring or early summer, you could solarize the lawn to kill it before mulching it. That's a process of using clear (not black) plastic to turn your yard into a solar oven that cooks the grass to death. At this time of year though, it will just keep the grass warm and toasty into the fall, and won't be effective.

If it were me (and it was me, two years ago) I would just do sheet mulch now, but know that you'll need to do spot weeding for a few years if your lawn is made of tough species and you don't want them coming back.
posted by agentofselection at 12:02 PM on October 4, 2021 [5 favorites]

I see in the latest update you have a tiller. You could substitute tilling instead of mowing in my answer then. I would go no-till after the pulling the plastic though.
posted by Press Butt.on to Check at 12:03 PM on October 4, 2021 [1 favorite]

Seconding chip drop, esp over cardboard. Stuff that will rot, but lots of it.
posted by clew at 12:05 PM on October 4, 2021 [1 favorite]

The sheet mulch method I outlined is the least labor and most effective way overall, but it's not the fastest. It can be extremely inexpensive if you can save cardboard and get it from shops, friends etc. You can buy mulch to put in top but you don't have to. I use leaves and twigs from my trees. You really just need some weight to keep it in place (and perhaps look a little nicer than plain cardboard).

Roundup is by far fastest and isn't that expensive. You seem to not want to do that, but my informed opinion as a plant ecologist is that if it's good enough for restoration experts, it's good enough for you. I haven't needed to use it at any scale because I do the sheet mulch or occulting methods.

The other main methods come under occultation and solarization.

Sheet mulch or roundup will have you ready to plant in the spring. Occultation and solarization will not.

I do not advise doing something you've guessed about over any of the four primary methods recommended by experts.
posted by SaltySalticid at 12:08 PM on October 4, 2021 [6 favorites]

I'm slowly turning my yard into a no-mow-zone using cardboard several layers thick covered with mulch. See if your city or local tree service has a mulch program, or sign up for chipdrop as mentioned above. My city gives away mulch 1 day a month and I get cardboard from nearby stores. No guarantee on quality or contents (people throw everything in their bins for pickup) but it does the job and will be in good shape when I'm ready to plant food next year. Even without the mulch, cardboard weighed down with rocks over a winter will get you pretty far.
posted by headnsouth at 12:09 PM on October 4, 2021 [1 favorite]

Response by poster: Thanks folks! I'll try to get additional advice about sheet mulching from the gardeners in my area. What I don't understand is - what do you do with the cardboard and mulch when it's time to plant? Do you just till it right into the ground? I don't understand this at all.
posted by kitcat at 12:16 PM on October 4, 2021 [1 favorite]

Once you start sheet mulching you don't till anymore. Just punch a hole in the cardboard/mulch and plant, and then continue layering mulch and compost on top.
posted by overeducated_alligator at 12:19 PM on October 4, 2021 [6 favorites]

The Garden Professors blog (previously on Metafilter) is a great resource on this. The blog is run by a group of scientists studying horticulture -- hence the name. They have a big section or running them on 'myths' -- worth checking out because a lot of what you will hear from people turns out to not be validated when actually tested.

They get a little strident at times, but they back it up with studies. A couple of big lessons I picked up was you want to preserve soil as much as you can. Excessive compaction or non-compostable barriers damage soil. Consequently, they come out hard against impermeable barriers like tarps and plastic sheeting for gardens (not necessarily for agricultural production however).

They also caution that newspaper and cardboard, while much better than impermeable plastic sheets, do negatively impact soil health. Their answer instead is thick mulches of wood chips (not wood bark). If thick enough, this will block sunlight that will very effectively suppress grasses.

Here's their post on How to get rid of your lawn. Basically, the routine is: mow the grass as short as possible, spread 6-9 inches of wood chips, wait a few weeks, plant directly into the mulch.
posted by bumpkin at 12:40 PM on October 4, 2021 [7 favorites]

The cardboard and mulch will be decomposing into soil -- and probably darn good, high organic matter soil -- from the bottom up. The idea is, good rot conditions at the bottom creating good soil, but loose quick-draining conditions at the top making a difficult environment for weed seeds to germinate. (Some will because weeds! If you just kick them when you see them, you will kill most of them because their roots will pull out of the chips.)

You can plant through the whole thing, or shove the dry stuff over to someplace you want to be easy-weeding and plant into the exposed soil.

Your later mulch can run the whole gamut from "really rich compost that will support vegetables, but will also need weeding" to "nut shells, decay really really slowly, around ornamental bushes". Or once you have low-weed soil, you can lay out planters paper over rich compost and plant through that, it will reduce weeding a lot but decay in a year. Is handsomer than waste cardboard.
posted by clew at 12:40 PM on October 4, 2021

Does your sod have a plastic mesh in it? You really want to get that out if it does.

Deep mulching is usually pretty effective in smothering lawns without using plastic (which is made from petroleum and will end up in a landfill). 8-12" of woodchips should do it. You'll lose some to decomposition, but once you move on to planting you may need to remove some mulch so that it's only about 4-6" deep at most. You don't need to bother with cardboard or paper- these are concentrated forms of carbon that can deplete soils of nitrogen and can also cause problems with gas and water movement in soils. It's an okay way to use up excess cardboard or paper rather than recycling, but buying cardboard to mulch with doesn't make a whole lot of sense when you can just use locally generated mulch without the embodied energy of cardboard.
posted by oneirodynia at 1:19 PM on October 4, 2021

I would use the newspaper & cardboard; I did this and it easily composted over a wet Maine winter, and left easily tilled ground. It was @ 4" (a local weekly had lots of extra newspapers, and I raided recycle bins for cardboard).
posted by theora55 at 1:28 PM on October 4, 2021

Yes, to be clear, part of the objective of the sheet mulch method is that at the end, most of your yard will stay mulched with wood chips or other organic debris for the long term. Mulch has multiple benefits that you will want if you are moving from a lawn to individual plantings. By covering the soil surface, it increases water capture and retention, and suppresses weeds that would otherwise overtake the bare soil. You'll want to have most of the yard mulched, with small openings around the root crowns of your plants to let them breathe and prevent rot.

Mulch also has some drawbacks. Some wildlife (e.g. solitary bees) need bare soil, so it is okay to leave some areas un-mulched, but be aware they will need more weeding, and their soils will tend to be dry.
posted by agentofselection at 1:38 PM on October 4, 2021

kitcat I do this at a large scale - 1000's of metres to Hectares. I sow seeds of one or three plants that I can establish into the weeds that will overtop them. I also plant into weedmat squares to get same effect. Sometimes I use herbicides to 'steer' the weed mix to something more invasive that will also let the plants I do want to grow..

1 - Sow area in the seed.
2 - weedeat hard, or graze it off hard if you have access to stock.
- as an alternative spray paraquat at this point, and the dying/opening canopy will allow light in and seed to germinate.
3 - wait.

I also establish perennials as plugs/small plants and plant them on weedmat squares/underfelt/coffee-sacks and encourage them to spread.

I have used Trifolium - red clover, Lychinis Coronia - rose campion, various Phlox, Dactylis glomerata - cocksfoot grass, and am currently working on using Plantago - plantain..., as well as several NZ native grasses and perennials. I have ~100 species I can do this with, and have several large trials underway.

I'm trying to avoid herbicides (especially roundup); paraquat is safer for the system (versus instantly toxic to humans, while roundup messes up the whole system and is a chronic problem for human biochemistry, and kills soil mycorrhiza).
posted by unearthed at 2:04 PM on October 4, 2021 [2 favorites]

I have done this by giving it away for free on Craigslist.
posted by amtho at 2:28 PM on October 4, 2021

Response by poster: Yes, to be clear, part of the objective of the sheet mulch method is that at the end, most of your yard will stay mulched with wood chips or other organic debris for the long term. Mulch has multiple benefits that you will want if you are moving from a lawn to individual plantings. By covering the soil surface, it increases water capture and retention, and suppresses weeds that would otherwise overtake the bare soil. You'll want to have most of the yard mulched, with small openings around the root crowns of your plants to let them breathe and prevent rot.

But what if this isn't what I want? For instance - the style of garden I created the space I cleared this year is - squeeze a crap ton of flowers in there. No empty spaces. I don't care if this isn't the 'right' way to garden. It's what I like. Similarly, I want some microclover lawn. If I mulch the entire lawn then I get - a bunch of mulch with occasional plants? I feel like I'm being purposefully obtuse here, but this isn't making sense. I also hate the way mulch looks.
posted by kitcat at 2:49 PM on October 4, 2021 [4 favorites]

Then you just plant close-together through the mulch and the mulch will, unseen, finish decomposing under the billowing wanted plants.

Which means you're jumpstarting the condition billowing crowded plants are likely to get to after a decade, of growing in their own decomposing dead leaves and twigs.
posted by clew at 3:45 PM on October 4, 2021 [4 favorites]

The newspaper and cardboard compost over the winter; anything remaining will break up. You should be able to put flower seeds down under or in the compostables and have seedlings.
posted by theora55 at 4:02 PM on October 4, 2021

You can use the sheet mulching on small defined areas, and temporarily cover it with planters instead of mulch, if that works better. So think in terms of flower beds you want and lay the sheet mulch on that area, and use planters for a year. Next year choose another area, cover that and move the planters over and till the area that was covered last year.

I'm not a fan of mulch myself, since it needs weeding. I only use it under my cedar trees as mulch with an occasional weed I need to dig out looks better than bare dirt with an occasional weed I need to dig out.

Pallets can also be used instead of sheet mulch, if the boards are closely spaced. A tidy row of six pallets makes a temporary deck. Add a patio table and some chairs, an outdoor rug and a couple of planters and you have a nice little spot that looks attractive enough that the neighbours will nod approvingly, even if you never actually sit out there.

Consider renting a tiller, if you have not. You might be able to get one that would chew up your lawn sufficiently to make the removal of the sod unnecessary.
posted by Jane the Brown at 8:23 AM on October 5, 2021

If I mulch the entire lawn then I get - a bunch of mulch with occasional plants?

What clew said. There's absolutely no reason why you'd plant plants any differently when you've mulched. There are numerous types of natural mulch some of which you may find more aesthetically pleasing. My personal preference when the garden is not on a slope is mini bark chips, though they decompose fairly quickly. You're not going to see much of the ground once the plants grow in I assume? At any rate, you can always try it out in a smaller area first.

Natural mulch helps replicate conditions under which most plants grow outside of gardens. Soil is consistently replenished with organic matter and nutrients as dead plant matter is eaten by various organisms. Organic material in soil helps create and maintain soil structure and increases the amount of places nutrition needed by plants is stored (cation exchange capacity). It helps with water and gas infiltration (roots need oxygen) and prevents soil compaction. Mulch regulates soil temperature, and can stifle weeds (or at least make them easier to pull out. It reduces soil erosion and helps prevent microorganisms in soil that can cause disease splashing back up onto leaves when it rains. A mulched garden requires less water, less fertilizer, and is less hospitable to weeds. It's arguably the best thing you can do for your garden's health. I've worked professionally in numerous gardens in which the application of mulch made a huge difference to the perennial plants in just one season.
posted by oneirodynia at 7:07 PM on October 5, 2021 [1 favorite]