Sheet Mulching – Follow This Advice For The Best Mulch
In permaculture, sheet mulching is often done near the house to prepare a kitchen garden.
Sheet mulching is one of the best methods of building an organic garden, and today I’m going to show you how to mulch correctly to make a great sheet mulch. You may have also heard it called no till gardening or lasagna gardening, both of which mean the same thing.
There are many ways to make a yummy lasagna and there are many ways to make a sheet mulch, but no matter how you do it, you can think of sheet mulching as kind of like composting right in your organic garden. It’s mostly done to create new garden beds, and occasionally in existing vegetable beds during the fallow season.
Sheet mulching is an amazing way to smother weeds and build fertility and soil structure at the same time by layering various materials anywhere from just a few inches to 18 inches high.
It has a few advantages over composting, perhaps the biggest being that it’s less work in the long run. With a sheet mulch, you don’t have to get rid of the grass first, and once you put the materials down, that’s where they stay, whereas with composting you generally turn it a few times and then have to move it into your organic garden.
Sheet mulch takes longer to break down than compost, but that also means it lasts longer as a mulch.
Sheet Mulching Disadvantages
At the same time, a sheet mulch generally doesn’t get hot enough to kill weed seeds and pathogens. Fortunately, if you keep a continuous mulch, most of the weeds will be taken care of anyway, and if you’re using a diversity of materials from good sources, the few pathogens you’ll be introducing will be taken care of, too.
Unfortunately, some tenacious weeds can be introduced when sheet mulching, giving you some occasional weeding to do, so for some people, a proper compost pile can be less work in the long run. Also, if you already have slugs, you’ll probably have more when you build a lasagna garden. They love the stuff. That’s one reason why I put my sheet mulched vegetable garden in a sunny, hot spot and don’t over water, but a few often seem to show up anyway.
Sheet Mulching Materials
It can be difficult to get enough materials to sheet mulch a big area, so it’s often best done for a kitchen garden right near the house, which will end up covered in my most important foods for daily picking, such as herbs and greens. I may even do this inside a raised garden bed.
You can use many of the same organic materials for sheet mulching that you would use in a compost pile. Your main mulch types for nitrogen are manure, fresh grass clippings and even a few food scraps. For carbon – hay, straw and leaves. Plus we put some newspaper or cardboard on the bottom and perhaps some compost towards the top.
Sheet Mulching Process
If you’re a lasagna lover, you know there are many ways to make it. When I was a kid, my mom made incredible lasagna with lots of meat and cheese. Now, I follow a mostly vegan diet, and when I visit home, she’s nice enough to make incredible lasagna without meat and cheese.
Likewise, there are many methods of making a sheet mulch. It can be as simple as newspaper on the bottom and a few inches of compost on top, but for the best results long term, you might want to do something similar to what I do.
I start with a 1/2 inch layer of newspaper or cardboard on the ground to suppress weeds, and then water the heck out of it (which incidentally stops the newspaper from flying away before your next sheet mulch layer goes on). There’s no need to pull the weeds first. Even if you do this on a lawn, you don’t have to till up the lawn first – just mow it short and leave the clippings there.
In fact, sheet mulching can be a handy way to deal with weeds you don’t want to put in your compost, or with turf you’ve removed from somewhere else in the garden. Throw them under the weed barrier layer and you’re good to go.
Some people are concerned about the glues in cardboard and inks in newspaper, but they’re mostly fairly benign and should be broken down by microbes. I wouldn’t use glossy or colored paper, but I’m okay with the ink.
My finished sheet mulch in a nice, curvy bed that integrates with the existing beds.
From the bottom up, my sheet mulch often looks something like this:
- fertilizers such as calcitic lime based on a soil test, not a pH test – don’t just guess what your soil needs because you may be wrong (more on this another time)
- 1/2 inch newspaper or cardboard, overlapping a few inches to stop grass from squeezing through
- 1 inch manure or other nitrogen material (some people put this below the newspaper layer)
- 6-12 inches hay or straw
- 2 inches fresh grass clippings (incorporate this down into the straw)
- 1-2 inches compost
- 2 inches weed-free straw or leaf mulch to top it off
So those are the basics. Did I leave anything out? Feel free to ask me questions below or let me know how you do your sheet mulch.
Question: How long before one can plant in the bed?Thanks
In the past, I’ve always waited 6-12 months, but this year, I’mexperimenting with planting into it right away. I know some things likepotatoes and squash should do well. I’ll see about the others – I’llprobably plant 30-40 things. For each plant, I just dig a hole down into thesheet mulch and put a couple of shovels of compost in. I plant towards thetop, at the level of that top compost layer.
How did it work out? We just bought ourselves a farm and nede a lot of beds in just a month for vegetables and flowers that are growing from seeds in our celler rigget now. Should we just start sheet mulch now or would it be better to just lay out newspaper and than 5 inch later of compost instead? Or do we neeed to remove the old gras first since we are already to late? For sure we need to prepare for next spring already aswell!
It works okay, but it’s definitely not optimal. I wouldn’t rely on it for your main strategy.
I could really use some advice Phil! I am planning on sectioning off a small area in my backyard for (what some might call) a semi-formal vegetable garden. Currently its covered in grass. I plan on having raised beds for the veggies and walkways between them. Should i sheet mulch the entire area?.. even where the walkways will be? I am hoping to plant into it almost immedietly after mulching and all. any advice you have is greatly appreciated. Thank you!
Hi Nicky, no need to sheet mulch the walkways. Just put cardboard or newspaper or fabric on top of the grass and your walkway material such as straw or wood chips on top of that. Then sheet mulch the beds. You’ll probably need something to hold in the sheet mulch, which could be as simple as chicken wire or as complex as a wooden (or other) frame. If you’re going to plant right away, you’ll want a decent layer of well-finished compost near the top of the layer, and extra compost for the planting holes. It’s a little hit or miss as to which plants are happy in a brand new sheet mulch, but many of mine did well this year.
Thank you so much!! 🙂
So what I am wondering is do you direct seed into the mulch (like for lettuce, carrots, beans?) or are you only putting in transplants? It seems that there would not be enough sunlight for the little seeds to germinate, and the top layers too loose to hold the seeds….or maybe these plants only work in a mature bed??? I am planning on planting hundreds of carrots, parsnips and beans this year so I could really use some advice.
You’re exactly right, Sara. I mostly transplant into a new sheet mulch, although big seeds like beans work okay. But leave an non-sheet mulched area for small seeds like carrots.
If there are trees in the area being converted from grass to garden, how close to the tree trunk should the cardboard and other materials be? Also, is adding a top layer of landscape fabric (on top of the mulch) then covered with bark beneficial for long term weed prevention? Thanks in advance!
Hi Jim, I leave the rootball uncovered to be absolutely sure there is sufficient moisture and air exchange to the roots. So no cardboard or mulch.Landscape fabric can do an okay job at stopping weeds, but the disadvantages are many, the most important being that it stops the process of organic matter and nutrient cycling when the leaves fall every autumn. If I come across it in a landscape, I pull it out.
we would like to recycle wallboard/sheetrock by includeing it in our sheet mulching. have you tried this before?
Most sheetrock/drywall has chemicals in it. Sometimes it can be quite toxic, while sometimes it’s not too bad. But I wouldn’t recommend using it in a garden. It can be recycled though, if you can find a facility in your are that takes it.
Hi Phil,I have several lawn areas I plan to sheet mulch this fall, I also have a large pile of dirt that was removed when I put in a new sidewalk to our front door. Do you see any problems if I spread this extra dirt over the lawn before I apply the sheet mulch?Thx
Hi Jim, I think that’s a great way to use the soil as long as it’s topsoil (and not subsoil), which it sounds is the case, so go for it.
I have found this just does not work in the moist weather of the UK – too many slugs and they lay their eggs in the mulch, which leads to even more slugs. Fully composted material spread as a top-dressing works better in moist climates.
Yes, most mulches can exacerbate slug problems.
Hi, I am currently planning a large scale Milkweed meadow (7 acres). We have a bit of Star thistle in the meadow. I had planned on solarization, and grazing to reduce the infestation before fall planting. However, I do have access on site to very large amounts of sawdust and mulch( its a fire wood industry )While I realize this may need to be removed before planting due to acidity, what do you think about smothering the whole area with mulch?
I don’t think you’ll get enough benefit to make it worth the effort. I expect the star thistle will still come back after.
I am doing something a little different, I am replacing my grass in the front yard with an English garden. I left the grass, but removed it from the areas I had to dig a large holes. After we planted all the plants, we put down the cardboard. Converted our sprinkler to a drip system, which we secured on top of the cardboard. The question is what do I place on top of the drip hose/cardboard? The cardboard is placed around the plants. What do I do now? Do I use cedar mulch? Manure? I am also worried about slugs, I just read they like the cardboard.
I plan on doing the same thing on the other part of my front yard. I will have a path, fountain with native plants. It is now weeds and grass. Should I do it the same way I described above? I will be planting large plants, with deep roots, not to mention the brick pathway. Any advice or help is so very much appreciated!!
1. It’s nice to use a mixture of things, as you would in a compost pile. The one caveat is if the garden is going to have annuals, wood mulch isn’t ideal, but it sounds like this is a perennial garden, so yes, a layer of manure topped off with a layer of mulch would be great. Yes, slugs may like it. If you tend to have a slug issue already and have plants that slugs particularly like, it will be a decision.
2. Yes, it sounds like the same approach will be appropriate there, too. My one concern would be whether the cardboard will suck up most of your drip irrigation water. Eventually, it will get saturated and give some of that water up, and of course eventually-eventually, it will break down entirely.
Thank you. Very good point. I didn’t even think of the cardboard holding all the water. Hmm… Something I need to consider for sure. LOL . Now my brain is working overtime.
Do you have any advice on how to use saved rain water, that I can tie into my drip system via sprinkler system?
Please keep all the great information coming. It is so very helpful.
Thank you for taking the time to respond.
I don’t have any specific advice on that because it depends on your irrigation system design, but the simplest may be to attach a drip hose right to a rainwater barrel or cistern.
My wife and I are in the process of planing a raised bed garden for next summer and using newspaper and cardboard will be the perfect solution for getting rid of the grass. I will be watching your site for mare tips.