With increasing interest in reducing monocultural swaths of turf, summer water consumption, and the drudgery of mowing, many people are eliminating part or all of their lawns. We did this at home some years ago and can attest to the tangible benefit of reduced water bills during our dry summer months.
The question I often get is – how? Do you dig up the turf and throw it out, then fill in with topsoil? Or do you cut it, flip it, and then plant on top of it? Or do you cover it up with cardboard to kill it?
We’ve tried all of these methods over the years (except sheet mulch, because you already know what I think about that). What I now recommend is the easiest, cheapest, and most effective way to both remove turf and protect the soil. Here it is in four easy steps:
1) Mow your lawn as close to the ground as possible. Scalp it. If you can wait until it’s not actively growing (summer here in the west), that’s even better. Don’t water it!
2) Cover it up with – yes, you guessed it – a really thick layer of arborist wood chips. They need to be at least 8″ thick and can be as much as 12-18″ deep without negative effects. They will settle quickly, so you do need to put enough down to maintain a 6-8″ depth after a few weeks. The depth is important to suppress the turf as well as any persistant weeds (like those you can see in the above photo).
3) Wait. Turf decomposition will depend on temperature and water availability – warm and moist conditions are optimal. After 2-4 weeks, pull part of the mulch back and check out what’s underneath. When it’s easy enough to dig through, then you can…
4) Plant. Be sure to move the mulch aside and plant into the soil. Replace the mulch to cover the disturbed soil and keep the weeds down. It only needs to be 3-4″ deep at this point.
It’s that easy.
What could you plant in 8 inches of wood chips? I don’t get it.
You don’t plant anything in the wood chips. You wait until the lawn is dead, move the chips aside, plant, and then cover the bare soil with a thinner layer of the chips (or whatever mulch you like). Consider the chips a “place holder” for future plants, hardscape, etc. They just keep the area weed-free until you’re ready.
I’d still be concerned about that much wood chips over tree roots if the area is large. Doesn’t sound like the best idea to me. But in an area without tree roots or a small area, sounds fine.
I do like using thin newspaper, though, in small areas–just two sheets to slow down the grasses, etc., long enough to kill them. It’s thin enough that it doesn’t interfere with water penetration. Don’t have to move the wood chips after.
For greenbriar, I had to go nuclear and use carpet for two years. I could not mow in that area at all to keep it down due to the slope, and there was just too much to Roundup, but that would be pretty terrible for tree roots, I’m sure.
When I did, I’m a turf flipper. The turf is often the only real area of top soil you’ve got in a typical yard.
Published and ongoing research has demonstrated that thick layers of wood chips benefit woody root systems. There are no ill effects, since water and gas transfer are not inhibited.
You would be surprised on how long newspaper will last and how much water it inhibits. I do a demo were I put wet newspaper over a clear container and then puddle water on top of it. There’s no water movement through the paper except for an occasional drip. Air movement would likewise be impeded. You can imagine that wet newspaper over your face would not be very easy to breathe through.
You also don’t need to flip turf, nor should you want to. It disrupts both the root/mycorrhizal network and soil structure. Best to leave it in place.
So while I appreciate your successes, they are ultimately only anecdotal. There is no research to support the use of any sheet mulches as a superior method of weed control while preserving soil and root health.
I’m glad to hear that even thick wood chips don’t inhibit oxygen and water! I’d heard that beyond 2-4″, it was a problem.
The plural of anecdote isn’t data, but one kind of experiment doesn’t always include all cases. For example, if you want to kill greenbrier, 8″ of mulch will not do it. A foot or more won’t. I tried that. I have a very large lot and a wood chipper, and I tried using the area for storing wood chips and leaves for later use on it after cutting all the greenbrier to the ground. Greenbrier will happily pop through a pile of wood chips 12-18″ thick and then laugh at you. You have to use brush killer or REALLY thick sheet mulch to kill it, and even with the thick sheet mulch, you need heavy wood chips over it, or you’ll have to go out monthly and stomp it down as the greenbrier lifts it up. That probably does terrible things to other roots, so yes, it wouldn’t qualify as preserving soil health at all! But for us, since the greenbrier had pretty much killed all the trees around there by the time we’d moved in (except for tree-of-heaven…of course…argh), I wasn’t worried about that at that point. Nothing was going to grow there successfully until the greenbrier was gone.
Most people want to plant pretty quickly after they establish a new bed. Careful sheet mulching, if you don’t have anything too vigorous underneath, allows for this pretty much immediately, depending on what you’re trying to smother and how well you were able to scalp or weed it ahead of time. Putting 8″+ wood chips doesn’t. So 8 inches of chips are better, but if it’s an option that people aren’t interested in because they want instant gratification, it isn’t really viable. If you’re planning well ahead, though, it would be.
Being lazy, I will establish the bones of a shrub border just by throwing shrubs straight into our clumping-type lawn. (But this wouldn’t work in one that spreads by vigorous runners.) When I do that, I scalp, dig a hole (usually 1.5 times the size of the plant at the surface because it always tapers), and I flip the turf when I backfill. This kills the grass right under the dripline of the shrub so I don’t have to weed it later. Try that with some of the runner types, and they wouldn’t die, but the clumping ones die pretty well. Then I mulch heavily, with arborist or self-made wood chips when I have them and stuff in bags when I don’t, about 4-5″ deep away from the plants and 2″ under. With clumping grasses and clover, this is generally enough to knock them back long enough to die, but if I don’t flip the sod around the shrubs, it will grow back under just 2″ of mulch,especially with the supplemental water I give right to the shrubs (I avoid supplemental watering the rest of the area).
Of course, if I got 8″ of wood chips and just left it on the ground for a few months, my native soil would be a lot nicer when I came to stick plants in it. Wood chips are amazing with how they transform the soil under them. But for the people who buy a rack of plants and then go, “now what?” that doesn’t work as well. And for people who decide to actually start that bed they’ve been planning for years….
Hi Linda!
Thank you so much for all this great information. I was searching for some further information because I recently dug out my front lawn completely to prepare it for a California native garden. The city of Los Angeles recommends cardboard or newspaper mulching, which as I can see from your article is not your recommendation. Personally I’d rather not go through the extra trouble of laying down cardboard after I already spent days manually removing the grass. May I ask – since I have already removed the lawn manually, how much mulch would you recommend laying on top of the bare soil to prevent regrowth of weeds and grass? And what is the best way to encourage healthy soil – how long should I leave the mulch undisturbed before planting? Should I add water to the soil before/after mulch?
Input appreciated!
I would put down 12″ of arborist chips. That will be enough to keep weed seeds from germinating and prevent regrowth of most perennial weeds.
Let it sit until later this fall (for your area, perhaps mid-November). Pull aside, plant, and then replace mulch around yournew plants.
Great, that’s what I’ll do. My coarse mulch was dropped off today and I’m spreading tomorrow. Thank you for all your insight!
Ive used a ‘more labor but faster results’ method on smaller spaces. I dug up the turf with a shovel (4 inches deep or so), put it aside, dug up the soil (at least 6 inches), put the turf in the bottom of the trench, and replaced the soil on top. Then mulched. I searched a while ago for studies comparing methods (black plastic, sod cutting, herbicides, etc) but didn’t get far.
I’m now sure this will work. it depends on the type of the lawn (the grass itself) and the climate conditions.
There’s no doubt it will kill the grass. The mulch layer eliminates sunlight and the grass will die from lack of photosynthate. That’s why the mulch layer needs to be thick – so that the turf can’t use its last resources to push through. This method is a home landscape adaption of our restoration work (which we published in 2005) describing how to punch back perennial weeds like blackberry and give newly installed native plants a chance to get established. The only conditions I could see where this wouldn’t work would be either a desert environment or an extremely cold landscape (not enough water and too cold, respectively, for microbial decomposition). Under those conditions, you wouldn’t have a lawn, either.
Hi, Linda, thank you for this article. will your method work for smothering invasive weeds? I have a 3/4-acre “lawn” that is mowed weekly but is no longer grass. It is at least 90% invasive weeds, such as stilt grass and false strawberry, etc. I want to kill off the weeds and plant native shrubs, native small trees, and native perennials where I have weeds.
Also I’m confused by your instructions. Are you saying once I truck 12-18 inches of wood chips back there I would later have to remove them and truck them all back off the property? I’m not up for that
Do not remove the wood chips, just pull them back to plant. Be sure to plant in the soil, not the mulch layer.
It’s me again. When I researched lawn removal I was told by people who’d used this method that it doesn’t take long to kill grass but for it to decompose takes about 6 months. Under this method aren’t you planting directly into the dead but fully intact sod?
Hi Susan – it’s really environmentally dependent. The warmer and moister the conditions are, the faster decomposition goes. Mulching with fresh wood chips pretty much guarantees a warm mulch, speeding up decay. In my experience it takes much less than 6 months to decompose, especially in the summer. In the fall and winter, however, it will take longer. So timing is everything. The only thing left intact is that dratted mesh they use for producing sod. From a practical standpoint, you might mulch over turf a good 3 months before you want to plant. It gives you lots of time to plan! It also gives the soil a chance to recover from being compacted (as many lawns are), making it much easier to plant.
So once you’ve covered the lawn with wood chips do you keep it dry or water every once in a while to help speed decomposition?
Good question, Marie! I’ve never had to do this, but you can do a quick check to make sure it’s moist. (I should mention that I do this in the summer, when Seattle gets little to no rain for many weeks.) The top few inches will be dry (which is good – it keeps blown-in weed seeds from germinating). Reach down a little deeper. You should find that the mulch is moist as you get closer to the old sod. If not, you could always add water. Even though I’ve never had to add water, a hotter (and equally dry) climate might need a little water added. Good idea to check.
I just found your books and this site, and I am so grateful–they’re a huge help in sorting through all the gardening folklore out there! I recently bought a house and am starting to build a garden in the backyard (Olympia, WA). I’ll use the approach you describe for lawn areas, but in a big swath of the yard (the part that would be the best site for vegetables and perennials!) the previous owners scalped off the sod, put down landscape fabric, and covered it with pea gravel. The soil underneath the fabric appears to have a hardpan layer close to the surface. What would you advise here? Maybe woodchips with a layer of compost underneath? Also, any general advice for dealing with hardpan?
How does your garden grow ?
Barbara
(in Lacey)
I think the easiest way to answer this is to direct you to this post – which has photos of what our front yard looks like after getting rid of the lawn:
http://www.lawnreform.org/2011/08/the-lawnless-garden-of-prof-linda-chalker-scott.html
Kitty, the first thing to do is find out, approximately, what kind of soil you have. (Since it’s raining today, you won’t have to moisten it.) Rub some of it between your fingers. Does it feel gritty? Does it form a ribbon? Unless it’s good and sticky (forms a ribbon), it doesn’t have much clay, in which case I would do exactly what you suggest. Put down 1-2″ compost, then top off with 4″ or so of wood chips. Let it sit. It’s probably just heavily compacted and needs a chance to recover function. If it *is* heavy clay, don’t add the compost and just topdress with chips. Heavy clay doesn’t drain well and in addition is already full of many mineral nutrients. The wood chips are coarse enough not to impede water and air movement.
Thanks so much, Linda! I went out and did some excavating with the help of a digging bar, and…it’s actually a bit scary. There’s the top layer of pea gravel, with the landscape fabric beneath it. Under the fabric is a thin (1-2″) layer of loamy topsoil, in very nice shape. Under that is a 4-5″ layer of hard-packed older gravel (which I first thought was hardpan), impermeable to spade/fork but which can be broken up fairly easily with the digging bar. And under *that* — is an old layer of plastic sheeting. Under which is solid heavy clay. (Dun-colored, sticky, ribboning.)
I think, once I get the pea gravel/fabric off, I may just use the bar to loosen up the sub-layer of gravel and punch holes in the plastic, layer compost and woodchips on top, and call it a day, keeping to vegetables, annuals, and shallower-rooted perennials in that part of the yard. Raised beds could be another approach. I don’t know that I can deal with getting the layer of plastic dug out, and the gravel layer on top of it does at least seem to be helping with drainage.
Anyway, thanks again, and of course I’d be grateful for any other ideas you might have.
The idea that a lawn needs to be killed is so exotic to me. In southern California all you have to do is stop irrigating. One summer later, just stomp over the crispy remnants and watch them fall into the cracks in the soil. No more lawn!
Kitty, I think your approach is probably the best. You’ll probably have a perched water table there, regardless of what you do. We also have an area of our yard with clay underlying a relatively shallow topsoil. (Check the entry on March 12 and 15 for more on perched water tables). Groundcovers and other shallow-rooted plants do ok there, but typical trees and shrubs do not. We’re going to put a deck over part of this area, which is functionally useless for landscape plants.
Thank you for posting this. I got my first free load of arborist wood chips delivered this weekend and am going to use this technique to build my vegtable beds.
I have another question. I took a Seattle Public Utilities class on designing a home drip irrigation system. While the class was chiefly about drip irrigation, the instructor also advised us not to use soaker hoses on vegtables and fruits because they are made of recycled tires and will therefore leach harmful chemicals into the soil. The instructor said this a known risk because of reserach done on the recycled tire prodcut used on playgrounds. When I did my own preliminary research, I could not find any scientific studies to back up this claim. What do you think about soaker hoses? Is there any known risk from the plastic tubing used in drip irrigation systems?
Thank you and your fellow garden professors for this blog.
A few years ago I client of mine made me a call to get rid of the lawn he had in the back yard and the reason why was the water bill. The cheapest way to fix this problem was to mulch it all over, but after having it that way he wanted a wood deck over the area.
Black plastic bags covering the area you’d like to work on and few days after that lawn will be gone. We use weed-barrier to get rid of the lawn and to make sure it won’t grow underneath the wood deck. Thanks for reading.
Black plastic will not only kill your lawn but anything else in your soil that uses oxygen. It’s not a soil-friendly way to eliminate lawn, and I don’t recommend it. (And weed barrier is not a permanent fix – it breaks down and is quickly colonized by weeds.)
Organic gardeners often wonder how to kill grass and eliminate lawns without excessive work! Using black plastic to kill grass and weeds is an easy, inexpensive and environmentally friendly option.
OK, Deck Builders Miami, I’m going to assume that you aren’t reading what’s being posted here. If I get one more spammy type of posting (by which I mean one that flies in the face of any scientific evidence), I’m going to delete all of your postings.
Okay so it looks like I’ve already made a big mistake as the lawn behind myself has been covered in black plastic since the spring. (Due to a surgery, I cannot remove it this autumn). Given that, what is my next move? Arborist chips? Topsoil? Compost? Layering? Thank. you!
Arborist chips once the plastic is removed.
It was not our intention to disagree with you. We tried to give our opinion based on our experience, thinking on a different way to get rid of the lawn.
It’s okay to disagree! But for this blog, it has to be science-based disagreement. Plastic has been definitively shown to injure soil life, based on its reduction of water and gas transfer. It can’t possibly be construed as environmentally friendly. (We get so much spam on the site that we have to constantly monitor whether comments are real or generated. Thanks for replying!)
Seed-bank question: will the 12” AWC layer kill weed seeds in the soil? Or will they germinate when I pull back the mulch to hand-sow wildflower seeds?
Seeds do not have enough resources to push through 12″ of SWC mulch, but they don’t die. They just stay dormant. Depending on the species they may have a long “shelf life.” So yes, once you pull mulch back and light reaches viable seeds, some will be able to germinate. The only approach is to keep an eye out for known weeds as your various seeds germinate and pull them by hand.
What kind of chips- fir, hemlock, cedar?
Esther, you can use any kind of chips you like, as long as they are relatively coarse. I tend to prefer conifer chips just because they smell so good. Usually I get fir, but yesterday we just got our annual load and it’s pine this year.
Can arborist chips be used from trees whose cause of death is unknown?
Yes. There is no evidence that diseased wood will spread disease to healthy trees if the wood is used as a mulch. https://www.researchgate.net/publication/315662938_Using_arborist_wood_chips_as_a_landscape_mulch_WSU_Extension_Fact_Sheet_FS160E
Would this be a safe technique to use under a mature dogwood? I want to remove my lawn so I can landscape under the tree but I’m concerned about its shallow root system.
So, suppose suppose you were lazy and planted some small trees first… and then built the bed around it. Would tree’s be hurt by the amount of mulch it takes to kill grass? Obviously I’d keep it several inches away from the trunks, as the grass there is already dead anyway.
I’m all for the layering method. That’s what Mother Nature does. When I first moved to my property, I spent a couple of days cutting turf in order to make flower beds. I still have to fight the grass in those spaces.
As I got smarter, I realized that layering leaves (carbon rich), arborist chips (also carbon rich), and grass clippings (nitrogen rich) was a much better way to kill the grass without exposing weed and grass seed. It heats up nicely as it decomposes, and also encourages beetle, worm, and rodent activity to turn over the soil on your behalf. The only thing it doesn’t do is remove rocks.
If I had it all to do over again, I’d have been out encouraging arborists to dump their wood chips at my place and would have spent the first year there “designing” the flower beds on my acre with piles of wood chips.
I live near Sacramento ca. I want to try your lawn killing method on a broad swath of grass under very old blue oaks. Will the decomposing 12 inches of wood chips generate so much heat that they kill the oaks’ surface roots or otherwise hurt them? The oaks are accustomed over many decades to summer water unfortunately. Do you know if we will still need to water the oaks after we kill the grass?
The heat generated by the decomposing chips won’t hurt roots, because the soil environment is vast and heat is easily dissipated. You may still need to add some water but not nearly as much as when you have grass there.
I heard you talk about this on the Joe Gardener podcast then found this post to read more about it. I had 12 cubic yards of arborist wood chips/leaves deposited at my house this week and spent the last three evenings spreading them out in my back yard. Hope this works… Goodbye wall to wall grass!
That’s great to hear! Consider taking photos and posting them on our Facebook group http://www.facebook.com/groups/GardenProfessors.
Update: I know it’s January, but I’ve got the bug and I am itching to get under my wood chips that I laid last year so I can start planing native trees and woody shrubs this year! Yes, I’m giving my lawn almost a year to decompose under the wood chips and for those microorganisms and other creatures to break that all down and improve my clay soil before planting this coming spring. I have a follow up question though: You advocate (as do others) for putting compost and wood chips directly on top of the soil instead of mixing it in. That makes sense from the way nature works and how decomposition works mixing it into the native soil. However, how come water passes easily from one layer to another in this system as opposed to creating perched water tables since they have differing structures?
It’s a great question and has to do with the nature of wood chips. First, they aren’t a soil layer (which is where you have problems with perched water tables). Water movement in soil depends on continuous pore space in soils and in layered soils that continuity is disrupted. Second, wood chips absorb water like a sponge and release it slowly to the soil underneath. Third, those wood chips are colonized by microbes, especially fungi, whose hyphae serve to transport water and nutrients through the soil to the fungal bodies and in the case of mycorrhizal hyphae to plant roots. So it’s a combination of physical, chemical, and biological processes that allow water to move from a woody mulch layer into the underlying soil.
Hello! I’d like to get rid of my lawn in my front yard in order to plant herbaceous native plants in an English cottage garden style in the spring. I’m in New York so it’s wet and cold at present. If I use your approach, I’m wondering how far in advance I should put the mulch down? Also, I have heard that it is better to use a mulch that is closer in nature to the plants in question – so, for example, wood chips near trees but more leaf-based mulch for herbaceous plants. I’m wondering if wood chips wouldn’t be too heavy for the plants I’d like to have in their eventually? If so, could one use this technique with a different mulch?
Hi Nicole –
Leaf mulch can’t be applied deeply, nor does it provide the woody material than many beneficial microbes need to survive. There is no science behind the belief that you have to use mulch material that is similar to the plants you are using. Wood chips are appropriate anywhere that you could grow woody plants (they would not be a great choice for a cacti garden in the desert, for instance).
Put the mulch down now after scalping your lawn. That should give you sufficient time for the underlying lawn to die back. Be sure to apply it deeply to prevent any light from getting through. Rake it aside and reuse when you are ready to plant.
I have some crazy big weeds in my backyard. I live in Ontario, Canada. Will this 8” of mulch method work to kill them as well? My backyard is basically weeds, big, nasty, ones with a few sprigs of grass. I’d like to make it a garden with trees, plants, shrubs, with a mulch covering. It’s also on an incline which makes the top of the hill extra dry.
As long as you mow them to the ground to reduce their stored resources, then yes. Be sure to use wood chips, not bark. And if you can put more than 8″ down, do it!
A question about arborist wood chips…what is the danger of transferring disease, non-beneficial insects, poison ivy and other undesirables to my yard with the chips? I don’t know of a way to ensure the source of the chips will be free of diseased wood, chopped up poison ivy, termites, etc.
Hoping you can shed some light on this. Thanks
There is little to no danger of any of these things. Here is my fact sheet on using wood chips. http://cru.cahe.wsu.edu/CEPublications/FS160E/FS160E.pdf
Thank you. And little to no danger of the vine regenerating even after being chipped (as I was warned). I personally thought this to be unlikely, but PI isn’t something I want to take chances with. So grateful for your generous knowledge.
The only way vine parts will regenerate is if the chipper being used makes a very large chip. It’s highly unlikely but not impossible. I’ve never seen it happen nor have I ever heard of it happening from a reliable source.
Thanks very much, Linda. I think all my questions are answered.
I read this advice and I believe in its wisdom but I have a small little yard with no wheelbarrow, shed, or place to receive a big load of mulch. I had reasonable success this summer by covering the grass with a combo of old landscaping fabric, newspaper, cardboard and a thin layer of bagged mulch. After 8 summer weeks I raked back the mulch, removed the fabric, removed/chopped up the newspaper and cardboard, put down bags of compost and then put the mulch back. I’ve planted a few things in it so far and haven’t had grass come back or many weeds (the lawn was fairly new post-construction so perhaps it was easy to kill). FWIW the newspaper in many places was barely degraded but the cardboard was mostly gone. The fabric was easy but of course now I still have this fabric. I’m in MD.
Yes, sheet mulches will kill the weeds. They also kill anything else living in the soil. We just published a paper on the ability of carbon dioxide to move through mulches. A single layer of cardboard is 10 times worse than wood chips. A single layer of landscape fabric is 100 times worse. We do not recommend killing off your entire soil ecosystem simply to remove weeds.
If you can’t get a big load of chips, contract with someone to bring you a pickup load. It won’t cost as much as all those bags of compost and is much better for your soil’s health.
Wait, compost isn’t good for soil health??
Not necessarily. Be sure to read Dr. Jim Downer’s post on the topic. https://gardenprofessors.com/the-yin-yang-of-compost/
Before I found this blog, I was trying to kill some grass and weeds for a new bed using plastic. Based on your advice and research, I have removed the plastic and switched to wood chip mulch. Since the top growth was mostly dead after a couple weeks under plastic, do you think I could get away with 6 inches of mulch instead of 8? My city provides free arborists’ chips now and then but I have to haul them myself and it’s a slow process. Like the above commenter, I don’t have room to have a large pile of chips dumped (although I would love it if I could).
Also based on your fact sheet link, it sounds like having leafy matter mixed with the chips is okay?
Thanks for the info.
Yes, by all means mix leaves with chips. That’s all god.
Glad to know that our research and recommendations are useful!
Hi! I like the idea of using an evidence-based approach so am so grateful to you for your work. I recently received a massive truckload of arborist wood chips Olin my driveway and am starting to work on carting them to my backyard. I’m told our soil was trucked after my house was built 15 years ago. It appears to be pure clay (Northern VA) or perhaps worse? ….My concerns are as follows: 1) I was taught in my tree steward class to *never* use more than 4 inches of mulch around trees. I’m terrified of harming my massive old growth oak trees in my woodland that is just beyond my back lawn. How is 4+ inches of mulch bad but 12 inches of arborist chips is ok? … 2) If I can somehow manage to cart and spread a truckload of arborist chips over my acre lot with my creaky knees that will be my swan song. I cannot later move them. They’re going to have to stay there. (I’ve experimented with using thinner amounts of chips in some areas and the grass and weeds push right through the chips in many places.) so can i still plant native plants into the chips if I wait longer?
4 inches is the minnimum. There is no reasonable maximum mulch thickness. Don’t plant in mulch pull it away and plant in soil.
What is the harm of using old tires as planters for flowers not vegetables? I live out in the country and trying to keep ahead of nutgrass, crabgrass and oxalis is a losing battle, I thought i could use the tires as containers along the driveway and lay a thick layer of chips around them to smother weeds in the the rest of the surrounding ground. Thank you for your advice. Daniel
We do not recommend the use of recycled tires for the reasons discussed in this fact sheet.
https://files.pubs.cahnrs.wsu.edu/FS163E/FS163E.pdf
Hi, again. I think you mistook my meaning, I was saying the tires filled with soil to limit the area I would have to hand weed. The area around and between would use arborist chips that could hide the tire itself and then only look like individual plantings. But I understand the objection to the rubber entirely and will have to find another container. My last question is, my sister wants some purple creeping Latania. If I plant it in 8-10 inches of woods chips with it be able to spread and put roots down that depth to the soil? Thank you. Daniel
Absolutely ground covers will eventually spread over the chips. Fresh chips will degrade fairly quickly – 10 inches will be 5 inches in a few months. The cover will spread over it and eventually send roots through the chips. That’s why I consider the chips to be a good place holder to be eventually replaced by desirable plants.
Thank you for the advice. Daniel
We put down 8-12 inches of arborist wood chips on our lawn area in April. It is successful and the lawn hasn’t reappeared! It is now late October. We recently planted a few native shrubs, just removing enough of the chips to plant them.
We also want to plant some native seeds to attract pollinators and create a small meadow like area.
Should I take up the majority of the chips and broadcast the seeds? Add some topsoil? Is this long enough for the lawn not to come back?
Advice would be appreciated!
Thanks.
Hi Mary –
Yes, to get seed germination you will need to remove all but an inch or so of the chips. This also means you’ll get weed growth, but that’s what happens when you are planting from seed.
Congratulations on your no-till, no-herbicide lawn removal!
Why not water before mulching? (Sorry, was looking through thread to see if answer was here already, but cannot find). I thought water increased biological activity and created heat necessary to commence decomposition of lawn(?).
We’re trying to reduce resources to the weed we’re controlling (in this case lawn). Add water afterwards to let the chips soak. That way you’re not irrigating the lawn.
Hi Linda,
I’m looking to replace a lawn with an edible landscape, using raised beds. First I’d like to put down a 8″ layer of arborist chips, to rid my yard of grass.
1.)Can I place the raised beds on top of the fresh arborist chips, fill them and plant immediately, or would i need to wait for the chips to decompose?
2.) Crabgrass is a major factor in this lawn. It already comes up in a 16″ raised bed I have established. Should I use/consider a pre-emergent, or will the arborist chips be enough?
Thank you
Hi Jessica –
Yes, you can put the bed on top, but it will probably settle unevenly. It would be best to wait if you can.
As long as you can control the crabgrass COMPLETELY (in other words, there isn’t crabgrass adjacent to the bed), then you won’t have a problem. If you can’t control it, then put down a root barrier deep into the soil surrounding the raised bed to stop rhizomatous growth.
Hello Linda,
I live on a corner lot in Central Oregon (Bend) with MANY feet of grass parking aka “hellstrips” surrounding our property. We are anxious to remove ALL of the lawn in those areas without hauling it to the landfill. It has been difficult to find any information on this subject for high desert climate. Would you recommend the wood chip method in this situation?
A “landscape” friend suggested that we flip the sod over, stack a few strips on top of one another to “contour”, then add landscape fabric and a thick later of mulch on top. It was also suggested if we were to add drought tolerant plants, to cut out areas in the sod and add soil etc. before planting. I would appreciate your thoughts on this approach and any suggestions you may have.
Wow. That recommendation will create all kinds of problems to your soil bed.
Yes, do use the mow and mulch method. Don’t cut and flip. It does nothing but destroy soil structure. Landscape fabric is not permeable to either water or oxygen. You want no barriers between your new plants and the improved soil that will develop underneath a wood chip mulch.
Thank you Linda!
Is this a good option if I’m trying to turn the lawn space into a meadow? I would like to seed new plants instead of planting.
Yes you can do this – just clear off all the chips when you are ready to plant. And be aware that you will have a lot of weed seeds to battle at the same time.
We’ve been designing and installing native grass and wildflower meadows for about 20 years. Using wood chips to kill off existing vegetation would seem to make little sense, except, perhaps, at very small scale.
The cost and effort to furnish, spread, and then remove the chips would be prohibitive on anything but a very small site.
The most economical, efficacious, and, i’d argue, environmentally responsible method is to herbicide existing vegetation for a growing season before seeding or installing the meadow plants.
I don’t know how anyone can argue that herbicide is environmentally responsible. It might be economical if using on a large site, but in no way can it be good for the environment. Pesticides (an umbrella term for herbicides, insecticides, fungicides, rodenticides, etc) cause many problems for all kinds of life besides just killing things.
Linda,
It’s incredibly rare that you’ve been so attentive to this blog post and its comment section for an entire decade, shooting down unscientific claims and offering positive suggestions. Most blogs you find from 2010 or prior are abandoned Internet graveyards of dead links. Thanks for being awesome for ten years straight.
I’ve ordered a load of arborist wood chips and can’t wait to attempt this method.
Thanks, Jon! The blog remains popular with visits from all over the world, so I do spend time maintaining older posts. We post new stuff about once a week, but we’ve got a shrinking pool. But I’m committed to keeping it going as long as I can.
Enjoy your chips – it’s about as close to a miracle product that you are going to find.
Hi Linda,
Thank you for the informative posts!
I’d like some advice to see if I’m headed in the right direction:
I’m near the Seattle area and I have a lawn I’d like to replace with a veggie garden (no grass and weeds!). The lawn has a very thin layer of top soil. When I dig, underneath is very hard layer of rock that I can’t easily get past. I’ve decided to turn to raised bed gardening for growing veggies next year.
In order to get the area ready for next spring, I got 20 cubic yards of arborist wood chips dropped and I’ve layered it 12″ deep in the area. I figure just before planting time next spring, I can build some beds (12″ high) and order some top soil, compost and coir to fill the beds. This should give the wood chips enough time to break down and settle.
I’m hoping that by doing this it should be good enough to grow root vegetables, and that the 12″ height of the bed wouldn’t affect the acidity of the soil — short term and long term as the wood chips break down below.
What are your thoughts?
It sounds like you are doing exactly what you need to. Whatever chips are left in the spring, move them aside and plant. And don’t worry, chips do not affect soil pH. After your veggies come up, you can use those old chips in between the rows.
Hi Linda,
I have read through all of your replies and am also amazed that you have been so kind to answer all questions.
I am about to setup a small market garden of 500 m2 (0,1 acre) in Denmark, but we have clay soil and lots of well established “quick grass” we call it, (Elytrígia répens).
I’m considering using bark chips in order to both kill the weeds and start building soil structure faster. You recommend not to use bark chips though and I wonder why?
And concerning the quick grass, say I cover a perimeter of 3-4 meters around the garden (I read that quick grass roots travel up to 10 feet), with wood chips (not bark), do you think this would be a viable strategy to keep out the quick grass?
Thank you 🙂
Hi Nathaniel –
I don’t recommend bark because it’s a hydrophobic material – it’s full of waxy materials that help keep water in the tree and disease out. It doesn’t break down quickly, meaning it’s not a very good resource for beneficial microbes.
The problem with keeping out invasive weeds from adjacent sites is that their underground stolons can run for long distances, because the parent population sends resources to them. The only way to keep them out is with deep root barriers, if you are not able to control the population. Or you can use a translocatable herbicide.
Great idea and I’m thinking of doing this technique. My concern is the meshing from our sod lawn being an issue. Should I pull up our lawn rather than this technique?
We had the same problem in our Seattle landscape. It was sod with plastic mesh. Rather than dig everything up, we left it in place (it was already breaking apart) and as we planted things we removed the pieces that were in the planting area.
Kudos for replying to comments on this for over a decade! I’ve been reading a lot of your articles recently as I transform my yard into a perennial wildlife garden. You’re one of the few sources I’ve found with the amount of no bullshit scientifically rigorous advice I need.
My question is pretty specific: do you think 5-6″ of very fresh white pine chips laid down in the winter (northeast) is enough to kill grass? I’m mainly wondering if fresh pine chips may be better at killing the grass and if the time of year might make it more effective as well.
Thanks,
Jeff
The best time to tackle the lawn is when resources are low: winter in a cold climate where the grass turns brown. Scalp it well, then try the chips. Fresh chips will settle by about 50% over time, and this may not be sufficient to kill the grass as sun can pass through thinner layers of chips. If you can double the amount it will work well.
Hi, Linda. Just discovered your website! I am also in the Seattle area (Renton). I have .5 acres on a hill. I want to kill the entire yard’s worth of grass and weeds. Spreading wood chips by hand seems impossible for me and is challenging due to hilly terrain. I’m considering using Pacific Top Soils blower service. They can blow in wood chips or hog fuel. They aren’t really chips . More like shreds. Do you think either of those would work? A friend of mine got a chip drop last summer and it was mostly cones, needles, and branches/twigs from a Doug fir. The one time I used arborists chips, they were from my own trees. They chipped them into the truck then dumped them for me. Except I also get leftover stuff that was in the truck like gravel and rocks. Ugh.
Without knowing the exact product being used we can’t make recommendations.
We don’t comment on commercial applications or companies.
Hi Linda,
I appreciate your input on this method versus sheet mulching, because I’m currently locked in an unending battle here in Atlanta against Bermuda and other stubborn invasive plants exploding through the initial install back in February.
In this situation, would it be appropriate to top dress another 8 inches around the plants already installed or would you recommend pulling out the existing sheet mulching and then starting from scratch? I think that the chips originally used are also breaking down more rapidly than expected and creating a fertile layer that is definitely not helping from a weed perspective – currently it’s me against a 1/4 acre grass removal area, and you can imagine who is winning.
Thanks for your time!
Starting over would be the best idea.
Remove the sheet mulch, do not reapply.
Scalp the grass and invasive plants as close as possible.
Apply a thick layer of wood chips, 12″ isn’t too much. Give them time to work, apply more chips as needed.
Use an herbicide to spot treat stubborn areas if necessary.
Keep after it. It may take a few seasons to fully remove the plants and deal with the seed bed.
Good afternoon! I’m in the Twin Cities in Minnesota and am looking to kill our lawn (to replace with a mix of veggies, flowers, native plants, etc). We’ve been chipping away at it and have tried a couple of methods. We’ve used a sod kicker, we’ve tried cardboard. The sod kicker was great, but definitely didn’t take care of all of the grass, and the cardboard has been there far too long to not have decomposed (lesson learned!).
Our challenges: we have raised lawns surrounded by sidewalk, so we’d end up spending a fortune on borders if we built things up significantly to hold mulch in; we really do not want to encourage chipmunks, mice, etc. to come in greater numbers to our lawn (and then basement); we have trees to protect; and we don’t want to spend an incredible amount of money regardless.
Do you think that a layer of leaf mulch (mostly maple) and then a layer of arborist mulch will do it? And do you have suggestions for what to do on slopes or near sidewalks and the like that we cannot have mulch scattering all over every time in rains?
Give it a try. Keep in mind a layer of entire or un-chopped leaves can make a mat which will interfere with water and oxygen access. But then again it may finish smothering the weeds.
Re: slopes-installing berms and swales can help slow water movement across a slope. Physical barriers such as rocks, logs, large branches, straw wattles or blankets can help as well.
Getting plants established as quickly as possible will slow runoff.
Dr. Chalker-Scott,
I join my fellow commenter with kudos to you for continuing to answer questions in this thread! Wish I had read this 5 years ago. I have done about half my yard by flipping sod and laying 3-5″ leaf mulch over it. I have planted a lot of natives in the result and they have been happy and no weeds. However, I much prefer the idea of just laying wood chips down and saving my back. During my initial research on how to convert the lawn, I must have read somewhere that the micro-organisms would would use up the nitrogen in the soil during the decomposition process, hence leading me to the method above. What did I miss?
Sincerely,
Kent
Hi Kent –
I used to flip the sod over too but it didn’t keep either the grass or weeds from coming back. By scalping the lawn and covering it with wood chips, you keep light away from the root crowns of the grass and weeds and prevent their regrowth. The area within the wood chips will be very actively decomposing and using up much of the available N in the mulch. It does NOT affect soil N.
Can this be done in early March for May plantings? We may not be able to mow as the ground will either be frozen or wet. I’m in southern Ontario Canada (zone 6).
The important thing is that the grass/weeds are dead on the surface. Then yes, it’s fine to do this without scalping.
Thanks for all this information, Linda! I’ve been a wood chip advocate since I started reading your blog. I would like to transform a portion of my lawn into a bee lawn–are you saying I should cover this section in wood chips, let them decompose for a few months, and then rake them back and plant the lawn? That seems a little labor-intensive, but I’m not sure how else to do it. I’m in Minnesota, for what it’s worth.
Yes, exactly. You’ll need a deep layer so the sod dies off from lack of sunlight. It is labor intensive, but gentle on the soil and its inhabitants.
Dr Chalker-Scott,
We lost both of our two doggies over the past six months. Both were spayed females, 105 and 65 lbs. They usually relieved themselves in one backyard patch of grass about 6×16 ft. I have now scalped it and covered it with 12” of AWC (from eight Acer platanoides I had cut down) in preparation for planting some natives. But I’m certain the soil is very acidic from 12 years of dogs’ deposits. How long will it take to become sufficiently less acidic to plant trees and shrubs? Should I pull back the chips and treat the soil with something? Thank you,
Kerry
SOrry to hear about your dear pets, Kerry, But you’ll be happy to know it’s impossible for a topdressing of any sort (including manure) to change soil pH in any significant way: the soil volume is vast and the soil itself is well buffered. The wood chips contain sufficient microbes to eliminate any residual organic material. Just let the chips work their magic!
Thank you. Happy to leave the chips there through the summer and plant in the fall. The area gets lots of water from a gutter downspout so that will probably help the uric acid to break down. I picked up their solid waste regularly so I was mainly concerned about their liquid waste accumulation, but based on your response I won’t worry too much!
Dr Chalker-Scott,
This is such great advice. I’m happy to not use cardboard anymore. Does this method work to kill Bermuda grass? Last time I was removing a lawn with burmuda grass I used roundup and thought that was the only way to get rid of it. I hate roundup and do not want to use it this time but I’m worried the rhizomes will eventually work their way up through the arborist wood chips.
With appreciation,
Nicola, in California
For better and faster results you’ll need to use an herbicide on the Bermuda along with wood chips.Using an herbicide with glyphosate is an effective and safe way to help remove it.
“Roundup” may or may not contain glyphosate, always read the label to determine the active ingredient.
Hi Chalker-Scott,
I listened to your lectures on the Great Courses and found your blog. I’m so thankful that you are sharing your wealth of information on how to garden scientifically.
We recently bought a house with a good sized backyard (1/3 acre lot). The backyard has really bad drainage as there is a hardpan layer underneath the ground. We haven’t watered the yard for a while and it is now covered with a mix of dead and alive weeds, with lots of bermeda grass.
We plan to add a mix of underground pipes and dry creeks to help with the drainage. As our backyard is uneven, our contractor said that we will need to grade the land as well. I assume we’ll do the drainage/digging first, and then grading, and after that I want to cover the entire yard with wood chips. My question is that whether we need to mechanically remove all the weeds before grading? My worry is that mechanically removing the weeds will get rid of some top soil as well. I appreciate your help.
Liang
Dear Liang –
You can leave the weeds there and have the grading incorporate them into the new layer. Add your wood chip mulch when the grading is done and let’s hope you get some better soil as a result of all of this work!
Thanks for your quick response, Dr. Chalker-Scott! We have a lot of Bermuda grass in our yard in California, which I have heard to be a nightmare to remove. Do you know roughly how long it might take woodchips to kill it? I heard Bermuda’s roots/seeds run deep, and our neighbor has lots of the grass as well. I’m worried once we remove the woodchips to grow other ground cover such as Kurapia/Clover, Bermuda grass will re-emerge. Any good solutions for it? Thanks again for your generous help.
Liang
Bermuda rhizomes don’t run deep they’re just very tenacious. How long it takes to kill them depends on your grow zone. Allow extra time to be sure they rhizomes are dead. You can spot spray any pockets of regrowth.
Don’t remove the chips to replant. Leave them in place to decompose and build the soil. This will also let you know if any of the Bermuda grass has survived.
hi! we would like to kill of our lawn as soon as possible to plant some native plants sometime next year, but it is fall/almost winter in the bay area/ca. should i wait until next spring or should i start now with the wood chips process?
It’s best to do it right now. That way you will be able to ensure the covered weeds are dead, and if there are any perennial weeds that manage to make it through, you can easily pull them. You could then plant in the very early spring or wait until fall.
Hi! Could I use finished compost in place of wood chips? I have compost handy but no chips. I’m in Massachusetts, it’s the beginning of winter now and I’d love to plant it in the spring. Thanks!
Compost and wood chips are not interchangeable. Compost is fertilizer, wood chips are to protect the soil and slowly decompose.
Don’t use compost until you’ve had a lab soil test done so you know what the soil nutrition levels are. Ideally, have the compost tested as well.
Chips can be used whenever you’d like, compost should only be used if directed by a soil test.
Thank you for the valuable information!
I already have planted shrubs and trees in my lawn fields. I now want to remove the lawn. I could use this method, but what around the shrubs? It seems a bad idea to put 20cm of chips surrounding the trunk.
Also: we have had a serious case of rodents in some areas this winter. I just noticed it in the area I want to experiment with your technique. Would this be a negative factor for using chips? I’ve already read one should be careful with mulch when mice etc. are at the plot.
That amount of chips next to the trunk won’t present a problem, they’ll decompose fairly quickly. You can always pull them back from the trunk a little ways if it makes you feel better about it.
Hi Linda, I live in NW Oklahoma where Bermuda is most common (and some people might say popular). My dream is to have a lawn of alternative ground cover plants such as Creeping Flox, Roman Chamomile, and creeping thyme. I saw someone mention they had success in fighting bermuda grass with your method.
While im interested in the method, im a little confused on how to go about planting my new ground cover surrounded by mulch. Of course im wanting my plants to spread as much as possible.
Would the mulch impede the spread of such ground covers? If i planted germinated ground cover plants the recommended distance from each other, would it ever fill in to become one meadow? also, before it hypothetically fills in, do i need to continue adding mulch between the growing plants?
Mulch will not stop your ground covers from spreading. They will climb over the mulch and as it settles and decomposes the ground covers will likewise settle. I always keep exposed soil covered with mulch to prevent weeds from getting a foothold. Once ground covers are established they do a pretty good job of weed control on their own.
Wonderful blog. Intrigued to try this and improve soil health.
I am preparing to create large planting beds in east TN and I can get all the arborist chips I want. However, my HOA doesn’t allow them as a visible mulch. If I created a base of arborist chips as you suggest, is it permissible to top it off with a typical double shredded, undyed, hardwood mulch that has some leaf compost as well?
Yes, that’s what I’ve recommended in similar situations. Good luck!
Dear Dr. Chalker-Scott,
Loving this blog!
I’m hoping to grow a native plant meadow on my property in Western MA. It’s a former gas station and the soil is generally sandy and dry I’d like to start planting the meadow over my leech field, using the arborist wood chip method to kill the current vegetation.
This brings me to my first question: It seems to me that this is the safest non-herbicide method, given that the wood chips will still allow the soil to aerate?
And second, does this method work well if I plan to sow seed in the fall, before the snow? Will I need to completely remove the wood chips so that the seeds are in contact with the soil? In my somewhat limited experience it is difficult to completely remove wood chips from uneven ground.
Thanks for your insight!
Have you had a soil test done to determine if there are any contaminants and what the soil nutrients levels are?
Go ahead and use the wood chips. However much is left this fall, pull back to expose the soil for sowing. If the mulch layer isn’t very deep just push it back over the seeds. It will continue to break down over the winter.
There’s no need to remove the chips and it’s not recommended to do that.
Hi Linda, thank you so much for this wonderful article. I got a little too carried away and although I scalped my front lawn, I started manually removing at least 4 inches of soil so that wood chips wouldn’t overflow too much to adjacent walkways but realized I’ve removed or disturbed topsoil. After manually removing most of the lawns current grasses, is 4” of wood chips sufficient to help smother weeds in the next 6 months or so? Is it possible to just keep the same said wood chips and if needed, add more mulch after? Thank you!!
At least 6″ is usually recommended to control weeds.
Keep the current chips in place and just top up as needed.
Did you replace the topsoil you removed?
I am learning so much!! Thank you. (I was just about to use newspaper or cardboard.)
Just out of curiosity, what would happen if I put down a nice layer of arborist wood chips around some pool equipment … and then forgot to water it? (This area is hidden and there is lots to distract me.)
Come to think of it, there are living weeds there. (This area has no irrigation, but, we’ve been getting rain this year.) But I’m sure that mulch would prevent some of them. Or at least, it won’t get worse if I do mulch, will it? I don’t know that I will be able to weed there first. (After some groundcover research, this year I bought seeds for sedum and also poppies, but, that is a medium-term project.) I might yank out the really big weeds though. That’s kind of fun sometimes.
Is there ever a downside to arborist wood chips?
I hope it’s not a rude question – that’s not my intention – it’s just, I am one of those people who like to know What Not To Do first.
Is there any way I can make a mistake? I understand that mulch will not magically get rid of the weeds that are already there. ; )
And, thanks again for this blog. It is super boss!
Scalp the weeds before applying the chips. Remove any seed heads if possible before doing so.
Make sure the chips won’t blow or migrate into the pool.
Downside to using chips?…Can’t think of any.
I forgot to ask if you have any recommendations for keeping wood chips in place on a steep embankment. I may have some ivy ripped out of the embankment. I was going to try jute netting with wood chips blown on top but most of the chips will just slide down. I do plan to plant native drought tolerant ground covers but they will take awhile to establish and I don’t want a bunch of weeds to establish as I won’t be able to access them to remove.
Laura K
Berms and swales help slow water movement and help hold mulch in place. Rocks, logs and large branches will do the same and give a natural look.
Commercial straw wattles staked in place work well if you wish to invest in them.