Our research was conclusive that coarse chunky mulches (i.e. Interesting debate about science here, which Im not going to jump into. Roots, on the other hand, never go dormant and continue to grow as long as the ground isnt frozen. The soil is clay, only clay, lacking nutrients in it. As long as its not chemically treated, a little ground-up lumber is okay in your chip pile. Plastic mulch kills everything in the soil and that is not your goal. Our gardens are miraculous in their growth and require little to no water to sustain them even through this extensive drought. Its not the type of project that funding agencies would care much about so its not too surprising that no one has done it yet. My other question is regarding the weed seeds that are currently in the soil of the flower beds. But you dont explain the relevance of the observed rates of diffusion to subsequent plant growth or productivity. Not to kill weeds ~ I actually want to grow some weeds that are a part of my diet ~ but to get rid of the grass & instead create an herb & nutritious weed garden. The data he reports indicates there is no difference in wet-weight yield between the cardboard and no-cardboard plots.
I am not allowed to post a link to this article due to publisher restrictions. The point of this post and all the others is that you dont *need* the cardboard or newspaper: there is no demonstrated, added benefit published in the literature. Not enough for my total needs, but plenty to test with. ), Dr. Chalker-Scott, the Master Composters at Clark County have build over 1,600 square feet of lasagna gardens using cardboard as a weed barrier.
Thanks! Unfortunately, people who use this as a mulch are not paying attention to details on what might be more permeable. Wow, I am super impressed by this thread and its responses! If you have allergies, or are immunocompromised, I would wear a mask when you can see clouds of spores when the pile is disturbed. How anaerobic does it have to be? Is wood chip mulch the only option? If you are planting annuals you will have to repeat this process every year. It is a sheet method that breaks down over time, returning the gas concentrations to their pre-sheet norms. In your recent post, you stated, all sheet mulches are going to restrict water and air movement. One situation is making an honest mistake and asking how to make it better.
Is it beneficial to put a few layers of newspaper under the mulch to smother weeds more effectively? I am willing to do whatever to get rid of the bermuda grass runners. When I cannot ignore it, (b) I use a really high concentration of RoundUp; let photosynthesis do its thing a few days; and then cover the plant with cardboard and wood chips (if the vine is long, I wind it up into a clump to minimize the size of the cardboard). As you know, WSU volunteers have an obligation to provide science-based information.
Around perennial plants I take a sheet of cardboard that is roughly a similar area as the dripline of the plant and cut a hole in the middle for the plant. I worry about unfriendly chemicals on some cardboards. Mycorrhizae takes a long time to really establish and tilling breaks the fibers, which disrupts the networking. It is discussed a great deal in many of Paul Stamets books. 3 months ago, I put cardboard on hard dry ground on top of a hill, and covered it with 12 inches of leaves. Here is the quote from your abstract: Thats pretty complicated and I wonder why you wouldnt just use the thick layer of chips? Thank you! Many people use multiple layers of cardboard and compost. How do we know what level of gas permeability is adequate for maintaining a healthy soil life?
What might be the implications?
Graph from above makes it seem even worse than cardboard, at least for gas exchange. Ive done a post on how to start this process you can find it here: http://gardenprofessors.com/how-to-get-rid-of-your-lawn/ Weve now published research that shows cardboard significantly reduces gas transfer compared to wood chips. Having just started a garden, I have exactly no knowledge, anecdotal or experimental, about the cardboard question.
For example, I participated in a wetland restoration project. When laying on top of each other, as they compress and if damp, they are not as three dimensional as woodchip (i.e.
Recycled Cardboard Roll is great for Sheet Mulching! The difference is probably my choice of words. Thanks.
First, I love this whole blog with a scientific bent.
Im talking from my non-scientific but practical experience. We dont recommend guerilla hair because it is forest product and can be a fire starter. We demonstrated this with research, and published the results. I stumbled onto this site looking for information about potential harmful effects of cardboard sheet mulching, especially on insects. Here's a visual guide to the recommended materials for your lawn conversion/sheetmulch project.
He talks about it a little here https://www.youtube.com/watch?v=7WdM__pw7Sk .
The link only points to a short synopsis of the study without a detailed conclusion. This soil doesnt retain much. Hi Doug Also, mulch works well at suppressing weeds and preventing many new seeds from germinating, but in my experience, there are weeds and grasses that dont care how thick your mulch is, they will still grow up through it. Thanks, Tanya, for taking the time to read the information with an open mind and think about it objectively. My experimental setup would be three experimental units: nothing, 12 of mulch, and cardboard with 3 or mulch. . But you said the turf structure is gone, so its likely that your grass is completely dead.
Sure, Beth, shredded cardboard, paper etc. Over time, weve converted over 8500 sq. It comes up through just about anything. Bare soil is not really a good standard in nature, because it becomes compacted, But again, we needed to limit variability so we could get good comparisons of the diffusion coefficients for different mulches. (comparable to cardboard?
I live in Michigan. Get seasonal tips on how best to take care of your garden and landscape, along with updates on our classes, products, resources, and more.
But cardboard mulch fans swear that they find more earthworms under cardboard than anywhere else in their garden. Youll have to let us know how it goes. Here is the article related to my concern. Some weeds I bury in several inches of compost and soil, but for the truly pernicious weeds in degraded soil its the WAY at least for me. Seed germinaton requires very little light, and some require no light at all. If local arborists could not meet local demand then it might need to be sourced from woodlands of which I have no knowledge, which may not be managed sustainably, or perhaps the woodchip is derived from ancient woodlands being cut down (which is happening here in the UK on a dreadful scale, killing so much precious and irreplaceable diversity). Leaves that are tough and crinkly, like oaks, will not. Since mycellium breathe CO2 & produce oxygen beneath the soil it seems likely that if you inoculated cardboard to be used as a sheet mulch the fungi would take care of the oxygen needs. A total success with reasonable effort on our part. Thats what pre-emergent herbicdes will do. Also, the proximity of the garden area to the house (directly adjacent) has me worried about termites being attracted to the wood mulch and/or the cardboard. Just say no! to roundup. The other significant benefits of cardboard is that it allows the limited rainfall we get to be directed towards the plants, greatly increasing moisture at the roots. Science is not something that is only accessible for lab coated technocrats. Its really not an issue! If its not in direct food contact then it is regulated in an entirely different fashion than material that has direct food contact.
As it just goes down to the Trinity River down below. This blog is science-based, so thats what we focus on. That may seem like a good thing but the fact is that in the long run it has resulted in enormous damage to agricultural soils. Unless you feel there is any value in the content for others its not necessary to post this. I have experienced first hand the rapid decomposition of cardboard as we build our gardens 12-24 high and make sure the layers are well watered. You should be. Its hardly a mulch thats going to nurture soil life. Its not a controlled experiment, which would require a completely different approach. The researchers state their bias right up front: Our farm believes strongly in our use of cardboard mulch That is going to skew their perceptions, which is seen in their unsupported claims of causation (i.e., all these great things happened because of carboard mulch), when at this point its merely correlation. I did wonder about the suffocation and upset to insect habitat (thankyou cricket) it is a big area. Obviously the folklore on using cardboard as mulch is well ingrained, and lots of people havent yet been persuaded out of it. There is logic and science behind the oxygen theory of earthworm travel, but in fact getting the earthworms to the surface is the goal (aerating the soil structure near the surface), and moistened cardboard breaks down just fine *while also suppressing weed roots*now THAT is a win/win/win! That will only exacerbate the problem. I now know that I should put a bunch of compost on topand I think its OK to till that in, since there is no existing soil structure or beneficial organisms to protect. So its good to block CO2 gas diffusion to the atmosphere to some extent because a CO2 build up and lowering O2 in the soil suppresses the action of microbes that are just turning carbon into CO2 and encourages other soil microbes like Fungi that build soil organic matter that doesnt just end up back in the atmosphere. Long time no see. We are all learning as we go, and reading stuff like this teaches me a lot!
The only time sheet mulches are mentioned is in an off-hand oh, heres how you can create habitat for worms. IAnd there are no references, so who knows where this came from? I have shredded some of them in the past and used them for mulch.
Isnt cardboard full of adhesives and recycled paper that has undergone many industrial processes to make it usable again? I agree Jay. The kill was total and we ended up planting in the chips that were on top of the cardboard. My big problem is bermuda grass. There is no theoretical plant or soil science that would support the use of cardboard, so the additional lack of any practical published evidence means theres nothing that a scientist could use to support the use of cardboard, given the collateral damage imposed on the soil ecosystem (which is totally ignored by gardeners who are solely focused on crop yields). Arborist wood chips. The barrier to natural gas exchange and moisture penetration created by layers of cardboard affects not only the troublesome roots of perennial grasses and wildflowers, or the visible soil life, earthworms, insects, arthropods and other soil invertebrates. Its taught me a lotI previously commented about having used carpet as a weed-suppressant and you strongly advised against doing so again. The three certifications to look for: The optimum mulch for lawn conversion is coarse recycled mulch either pallet mulchfrom chipped pallets or arbor mulch from tree trimmings. If you have published evidence that disagrees with the research to date on mulches of any stripe, feel free to cite it.
If you know an easy way to shred cardboard, let me know, because the effort sounds like a loss overall. Since the article is behind a paywall, it might contain information that I miss. Could you comment on https://www.groasis.com/en wouldnt these kill the soil around the plants creating anaerobic conditions? Im sorry, but this is just way too long for me to respond to.
The standard panel width is perfect, it can be found cheap, will last for years and its easy to cut. Even shredded, cardboard is still going to act in a sheet-like manner. Im going to put this idea in my back pocket just in case. Anything that reduces oxygen diffusion into the soil will negatively affect the soil ecosystem and the more diverse and complex it is, the bigger the negative impact. Cardboard is NOT meant to last. Thank you so much for your dedication. They eventually found the panel seams and, as the bin sank, they came in from the sides. There are several vendors in the Bay Area who sell compost by the cubic yard and deliver it in a dump truck. That wouldnt be very effective as a mulch. https://www.researchgate.net/publication/315662938_Using_arborist_wood_chips_as_a_landscape_mulch_WSU_Extension_Fact_Sheet_FS160E. After reading your entries, Ive come up with this what do you think? Thanks for being open to the science behind garden practices!
Its a great way to use invasive species for something useful. Its much easier to add a deficient nutrient than to remove a toxic one. He states an important point in that whatever approach is made, a gardener should consider two things (1) providing material for the worms to eat whether organic or mineral and (2) providing an environment that fosters ideal conditions stabilization of temperature and moisture. You were doing well (even if you have no science to back up your claims) until your last major paragraph. Humanity has a very long history of figuring things are OK, until it becomes painfully obvious that they arent. Failing that, then the woodchip would have to be supplied from elsewhere. Eleven years old, and not relevant to applied plant and soil research. It also kills plant roots, earthworms, and so on.
Thanks for the reply. (Obviously a vertical weed barrier would be most effective but theres a path leading through the area to get to the backyard and shed. Linda, how would explain success of Charles Dowdings no-dig method using cardboard? Theres way more to the issue than soil moisture.
Great questions regarding mulch depths.
Cardboard is made with non-toxic (usually fish-based) adhesives.
You will see a link to published research at the bottom. Wood chips will not interfere with drainage. We know that fungus breaks down cellulose material, not bacteria. millions and millions of us) decided to follow your advice, i.e. My question is this. My speculation is that in clay soils that tend to hold significant moisture and an environment that gets significant moisture this may be more of a concern. 1) To prevent seed germination, you need at least 4 of chips. When you want to plant, move aside the chips until you get to a layer that looks composty and is moist. Arborist wood chips are organic materials that most closely mimics the natural process of debris accumulation on soil. We will be publishing our research within the next year so everyone can see these data. Earthworms dont come to the surface to stay moist and cool.
I was wondering if the chemicals that are found in cardboard would also be a reason not to use cardboard for mulch. On this page you have said, among other things: The only research Ive seen that uses cardboard is for termite studies (its their preferred food)., This blog promotes science and there is no published science behind using cardboard as a mulch. The best non chemical approach so far has been deep mulch with regular hand weeding of the weed as it becomes apparent.
You also state: which is totally ignored by gardeners who are solely focused on crop yields. Summercloud, with the friendliest of intentions I would recommend that you refigure your assumption on cardboard that isnt rated for direct food contact. I really recommend you dont till annything into your soil. I would put these onto a solid surface, such as a concrete pad. About 2500 sq ft. is vegetable garden and orchard. Ive been experimenting with using cardboard in a different context.
The crown should be at grade with the soil. We dont have time to clean up science. This is a logarithmic scale. Fantastic. Unknown species, and it really doesnt matter in that regard. Its a laboratory artifact.). https://pubs.extension.wsu.edu/using-arborist-wood-chips-as-a-landscape-mulch-home-garden-series. (One of the links in the first paragraph goes to a post explaining exactly how to do this.).
I am not allowed to post a link to this article due to publisher restrictions. The point of this post and all the others is that you dont *need* the cardboard or newspaper: there is no demonstrated, added benefit published in the literature. Not enough for my total needs, but plenty to test with. ), Dr. Chalker-Scott, the Master Composters at Clark County have build over 1,600 square feet of lasagna gardens using cardboard as a weed barrier.
Thanks! Unfortunately, people who use this as a mulch are not paying attention to details on what might be more permeable. Wow, I am super impressed by this thread and its responses! If you have allergies, or are immunocompromised, I would wear a mask when you can see clouds of spores when the pile is disturbed. How anaerobic does it have to be? Is wood chip mulch the only option? If you are planting annuals you will have to repeat this process every year. It is a sheet method that breaks down over time, returning the gas concentrations to their pre-sheet norms. In your recent post, you stated, all sheet mulches are going to restrict water and air movement. One situation is making an honest mistake and asking how to make it better. Is it beneficial to put a few layers of newspaper under the mulch to smother weeds more effectively? I am willing to do whatever to get rid of the bermuda grass runners. When I cannot ignore it, (b) I use a really high concentration of RoundUp; let photosynthesis do its thing a few days; and then cover the plant with cardboard and wood chips (if the vine is long, I wind it up into a clump to minimize the size of the cardboard). As you know, WSU volunteers have an obligation to provide science-based information.
Around perennial plants I take a sheet of cardboard that is roughly a similar area as the dripline of the plant and cut a hole in the middle for the plant. I worry about unfriendly chemicals on some cardboards. Mycorrhizae takes a long time to really establish and tilling breaks the fibers, which disrupts the networking. It is discussed a great deal in many of Paul Stamets books. 3 months ago, I put cardboard on hard dry ground on top of a hill, and covered it with 12 inches of leaves. Here is the quote from your abstract: Thats pretty complicated and I wonder why you wouldnt just use the thick layer of chips? Thank you! Many people use multiple layers of cardboard and compost. How do we know what level of gas permeability is adequate for maintaining a healthy soil life? What might be the implications?
Graph from above makes it seem even worse than cardboard, at least for gas exchange. Ive done a post on how to start this process you can find it here: http://gardenprofessors.com/how-to-get-rid-of-your-lawn/ Weve now published research that shows cardboard significantly reduces gas transfer compared to wood chips. Having just started a garden, I have exactly no knowledge, anecdotal or experimental, about the cardboard question. For example, I participated in a wetland restoration project. When laying on top of each other, as they compress and if damp, they are not as three dimensional as woodchip (i.e.
Recycled Cardboard Roll is great for Sheet Mulching! The difference is probably my choice of words. Thanks.
First, I love this whole blog with a scientific bent.
Im talking from my non-scientific but practical experience. We dont recommend guerilla hair because it is forest product and can be a fire starter. We demonstrated this with research, and published the results. I stumbled onto this site looking for information about potential harmful effects of cardboard sheet mulching, especially on insects. Here's a visual guide to the recommended materials for your lawn conversion/sheetmulch project.
He talks about it a little here https://www.youtube.com/watch?v=7WdM__pw7Sk .
The link only points to a short synopsis of the study without a detailed conclusion. This soil doesnt retain much. Hi Doug Also, mulch works well at suppressing weeds and preventing many new seeds from germinating, but in my experience, there are weeds and grasses that dont care how thick your mulch is, they will still grow up through it. Thanks, Tanya, for taking the time to read the information with an open mind and think about it objectively. My experimental setup would be three experimental units: nothing, 12 of mulch, and cardboard with 3 or mulch. . But you said the turf structure is gone, so its likely that your grass is completely dead.
Sure, Beth, shredded cardboard, paper etc. Over time, weve converted over 8500 sq. It comes up through just about anything. Bare soil is not really a good standard in nature, because it becomes compacted, But again, we needed to limit variability so we could get good comparisons of the diffusion coefficients for different mulches. (comparable to cardboard?
I live in Michigan. Get seasonal tips on how best to take care of your garden and landscape, along with updates on our classes, products, resources, and more.
But cardboard mulch fans swear that they find more earthworms under cardboard than anywhere else in their garden. Youll have to let us know how it goes. Here is the article related to my concern. Some weeds I bury in several inches of compost and soil, but for the truly pernicious weeds in degraded soil its the WAY at least for me. Seed germinaton requires very little light, and some require no light at all. If local arborists could not meet local demand then it might need to be sourced from woodlands of which I have no knowledge, which may not be managed sustainably, or perhaps the woodchip is derived from ancient woodlands being cut down (which is happening here in the UK on a dreadful scale, killing so much precious and irreplaceable diversity). Leaves that are tough and crinkly, like oaks, will not. Since mycellium breathe CO2 & produce oxygen beneath the soil it seems likely that if you inoculated cardboard to be used as a sheet mulch the fungi would take care of the oxygen needs. A total success with reasonable effort on our part. Thats what pre-emergent herbicdes will do. Also, the proximity of the garden area to the house (directly adjacent) has me worried about termites being attracted to the wood mulch and/or the cardboard. Just say no! to roundup. The other significant benefits of cardboard is that it allows the limited rainfall we get to be directed towards the plants, greatly increasing moisture at the roots. Science is not something that is only accessible for lab coated technocrats. Its really not an issue! If its not in direct food contact then it is regulated in an entirely different fashion than material that has direct food contact.
As it just goes down to the Trinity River down below. This blog is science-based, so thats what we focus on. That may seem like a good thing but the fact is that in the long run it has resulted in enormous damage to agricultural soils. Unless you feel there is any value in the content for others its not necessary to post this. I have experienced first hand the rapid decomposition of cardboard as we build our gardens 12-24 high and make sure the layers are well watered. You should be. Its hardly a mulch thats going to nurture soil life. Its not a controlled experiment, which would require a completely different approach. The researchers state their bias right up front: Our farm believes strongly in our use of cardboard mulch That is going to skew their perceptions, which is seen in their unsupported claims of causation (i.e., all these great things happened because of carboard mulch), when at this point its merely correlation. I did wonder about the suffocation and upset to insect habitat (thankyou cricket) it is a big area. Obviously the folklore on using cardboard as mulch is well ingrained, and lots of people havent yet been persuaded out of it. There is logic and science behind the oxygen theory of earthworm travel, but in fact getting the earthworms to the surface is the goal (aerating the soil structure near the surface), and moistened cardboard breaks down just fine *while also suppressing weed roots*now THAT is a win/win/win! That will only exacerbate the problem. I now know that I should put a bunch of compost on topand I think its OK to till that in, since there is no existing soil structure or beneficial organisms to protect. So its good to block CO2 gas diffusion to the atmosphere to some extent because a CO2 build up and lowering O2 in the soil suppresses the action of microbes that are just turning carbon into CO2 and encourages other soil microbes like Fungi that build soil organic matter that doesnt just end up back in the atmosphere. Long time no see. We are all learning as we go, and reading stuff like this teaches me a lot!
The only time sheet mulches are mentioned is in an off-hand oh, heres how you can create habitat for worms. IAnd there are no references, so who knows where this came from? I have shredded some of them in the past and used them for mulch.
Isnt cardboard full of adhesives and recycled paper that has undergone many industrial processes to make it usable again? I agree Jay. The kill was total and we ended up planting in the chips that were on top of the cardboard. My big problem is bermuda grass. There is no theoretical plant or soil science that would support the use of cardboard, so the additional lack of any practical published evidence means theres nothing that a scientist could use to support the use of cardboard, given the collateral damage imposed on the soil ecosystem (which is totally ignored by gardeners who are solely focused on crop yields). Arborist wood chips. The barrier to natural gas exchange and moisture penetration created by layers of cardboard affects not only the troublesome roots of perennial grasses and wildflowers, or the visible soil life, earthworms, insects, arthropods and other soil invertebrates. Its taught me a lotI previously commented about having used carpet as a weed-suppressant and you strongly advised against doing so again. The three certifications to look for: The optimum mulch for lawn conversion is coarse recycled mulch either pallet mulchfrom chipped pallets or arbor mulch from tree trimmings. If you have published evidence that disagrees with the research to date on mulches of any stripe, feel free to cite it.
If you know an easy way to shred cardboard, let me know, because the effort sounds like a loss overall. Since the article is behind a paywall, it might contain information that I miss. Could you comment on https://www.groasis.com/en wouldnt these kill the soil around the plants creating anaerobic conditions? Im sorry, but this is just way too long for me to respond to.
The standard panel width is perfect, it can be found cheap, will last for years and its easy to cut. Even shredded, cardboard is still going to act in a sheet-like manner. Im going to put this idea in my back pocket just in case. Anything that reduces oxygen diffusion into the soil will negatively affect the soil ecosystem and the more diverse and complex it is, the bigger the negative impact. Cardboard is NOT meant to last. Thank you so much for your dedication. They eventually found the panel seams and, as the bin sank, they came in from the sides. There are several vendors in the Bay Area who sell compost by the cubic yard and deliver it in a dump truck. That wouldnt be very effective as a mulch. https://www.researchgate.net/publication/315662938_Using_arborist_wood_chips_as_a_landscape_mulch_WSU_Extension_Fact_Sheet_FS160E. After reading your entries, Ive come up with this what do you think? Thanks for being open to the science behind garden practices!
Its a great way to use invasive species for something useful. Its much easier to add a deficient nutrient than to remove a toxic one. He states an important point in that whatever approach is made, a gardener should consider two things (1) providing material for the worms to eat whether organic or mineral and (2) providing an environment that fosters ideal conditions stabilization of temperature and moisture. You were doing well (even if you have no science to back up your claims) until your last major paragraph. Humanity has a very long history of figuring things are OK, until it becomes painfully obvious that they arent. Failing that, then the woodchip would have to be supplied from elsewhere. Eleven years old, and not relevant to applied plant and soil research. It also kills plant roots, earthworms, and so on.
Thanks for the reply. (Obviously a vertical weed barrier would be most effective but theres a path leading through the area to get to the backyard and shed. Linda, how would explain success of Charles Dowdings no-dig method using cardboard? Theres way more to the issue than soil moisture.
Great questions regarding mulch depths.
Cardboard is made with non-toxic (usually fish-based) adhesives.
You will see a link to published research at the bottom. Wood chips will not interfere with drainage. We know that fungus breaks down cellulose material, not bacteria. millions and millions of us) decided to follow your advice, i.e. My question is this. My speculation is that in clay soils that tend to hold significant moisture and an environment that gets significant moisture this may be more of a concern. 1) To prevent seed germination, you need at least 4 of chips. When you want to plant, move aside the chips until you get to a layer that looks composty and is moist. Arborist wood chips are organic materials that most closely mimics the natural process of debris accumulation on soil. We will be publishing our research within the next year so everyone can see these data. Earthworms dont come to the surface to stay moist and cool.
I was wondering if the chemicals that are found in cardboard would also be a reason not to use cardboard for mulch. On this page you have said, among other things: The only research Ive seen that uses cardboard is for termite studies (its their preferred food)., This blog promotes science and there is no published science behind using cardboard as a mulch. The best non chemical approach so far has been deep mulch with regular hand weeding of the weed as it becomes apparent.
You also state: which is totally ignored by gardeners who are solely focused on crop yields. Summercloud, with the friendliest of intentions I would recommend that you refigure your assumption on cardboard that isnt rated for direct food contact. I really recommend you dont till annything into your soil. I would put these onto a solid surface, such as a concrete pad. About 2500 sq ft. is vegetable garden and orchard. Ive been experimenting with using cardboard in a different context.
The crown should be at grade with the soil. We dont have time to clean up science. This is a logarithmic scale. Fantastic. Unknown species, and it really doesnt matter in that regard. Its a laboratory artifact.). https://pubs.extension.wsu.edu/using-arborist-wood-chips-as-a-landscape-mulch-home-garden-series. (One of the links in the first paragraph goes to a post explaining exactly how to do this.).