Question for Toby about sheet mulching

Hi Toby,

Welcome back to the forums and thank you very much for your very down to earth explanations of Permaculture techniques. Your book has inspired me to transform my backyard into an edible landscape. One of my goals was to use all materials that were on my newly purchased lot, so I used everything from topsoil, to rocks, weeds etc to create 9 raised beds for growing vegetables/herbs in addition to fruit and nut trees/bushes. My question on sheet mulching is twofold.

1. I have really crappy clay soil that is so hard I had no choice but to do raised beds, and I even had to do raised areas for the trees. I basically through down cardboard, and then used a steerloader to remove existing topsoil/weed layers from empty lots. I then turned it upside down so the growth was pointing down. I then took all the wood/leaf debris from the lot and piled that on top. Then I took broken topsoil from the lot and put it on top of that mess, the soil was really compact in to large chunks. I then put more leaves on top of that and then finally mulch from a community composting site. I am now getting a lot of weedy type growth coming out of the tops of the mulch and Im not sure if its from the community mulch or the bottom layer of grass/weeds that I turned upside down.  Any ideas on how to remedy the problem and do you think this will come back next year if I pull all of them out by hand?

2. There are areas that are bare dead dirt(not soil) around my house that are basically areas in between trees. I didn’t want to seed this for lawn for several reasons, but now I have to do something because weeds are popping up all over the place and are causing an eyesore, which is not a good thing considering Im trying to convince my wife we are doing the right thing! In some areas I have planted flax to hopefully break up the soil and provide ground cover, and other areas Ive planted beans for the same reason. Are there better choices for an annual ground cover? I thought flax would be a good choice but Im not sure if I can mow it and have it come back through out the growing season. Its really an issue of things getting too tall and making that eyesore effect. So if I can grow low cover that is attractive yet annual that would be great.


Thanks very much for any advice you can provide!

PS, I have a thread here regarding using plants to sustainably keep the soil acidic. I was thinking of growing things like garlic for underground sulphur mining and using dwarf mugo pines above ground for surface acidification. This would be for areas around blueberries, lingonberries etc.  Do you have an experience with this or can you point me to a resource to understand it better?

Thread here: https://permies.com/permaculture-forums/3311_0/permaculture/sustaining-acidic-soils

Those weeds could have come from almost any of your layers except the leaves. Chunks of soil will have weed seeds; the weedy layer will have lots, and all that soil provides a nice growing medium. The top 3-6 inches of material really needs to be weed free, and I wouldn't recommend having a lot of imported soil chunks--that's not mulch, that's soil. It will contain seeds and live plants, and provide them with a sturdy growing medium that an organic mulch won't, and it will be very hard to pull the weeds out of it, unlike a loose mulch. So I think that what you did by adding big compacted soil chunks made your project not very different from tilling, rather than mulching. 

For annual ground cover, at least in the NW (I don't know where you are), various clovers is excellent, or a vetch/oat mix. It depends on when you plant--the latter is a cool season mix. Buckwheat is a good warm season cover crop, and I usually mix it with some sort of peas or beans for nitrogen. I haven't worked much with flax so don't really know how it behaves. Without knowing where you live or what your timing is, it's hard to get more specific. A great resource for making cover crop decisions is the Peaceful Valley Farm Supply catalog, which is online at http://groworganic.com Dig around there and find the various pdf guides they have to cover crops, and much else. Very helpful stuff.

So when people ask questions here, let me know where you live and details like timing, soil type, etc, so I can zero in on the issues.

OK So if understand this, you are saying that I should not have used any soil? I thought that there was supposed to be soil down inside so the things we were planting had something to grow into. From your post it sounds like I should have just used all organic non soil material and planted my seeds etc right into the mulch and not soil? The one thing I did notice is that most of the weeds just pull right out so Im assuming they were growing from the mulch layer. I am trying just leaves and compost for my potatoes. I buried the sprouts into the pile and I will see how it goes.

Sorry about my location, its in my forum profile but I should have stated it also. I am in PA, zone 6. I figured you would suggest the clover. My concern is that it will spread all over the place. The groundcover im looking for definitely has to be annual, but I need something that can be mowed so I can keep the height manageable. Would buckwheat grow back? I do have tons of buckwheat seeds at my disposal.

Did you happen to see my post about acidifying soils sustainably? Just curious if you have any thoughts on the matter.

Thanks for taking the time to answer our questions!

Yeah, generally a mulch is loose organic material that will compost and become soil, but it's not soil itself. Am exception to this (there are always exceptions!) is that you can add some compost or clean, loose topsoil in small pockets or bands on the top of sheetmulch to plant seedlings or seeds into if you are planting into fresh mulch. Big seeds like beans can go right into mulch, as they have enough nutrients in the seed to grow a bit while the mulch breaks down, but small seeds should indeed go into small soil pockets or bands.

If the weeds pulled right out, then that's a sign that the seeds came from one of the mulch materials, rather than from the soil. That's good news.

I'll try to remember to look at people's profiles to see where they live, etc, but I'm flying through all these posts pretty fast and can't linger as long as I'd like (we're selling our house, I'm prepping for these two PDCs, my wife is out of town so I'm holding down the fort alone, traveling every weekend, blah blah blah, busy like everyone else!)

Wow that sounds a lot easier than what I did. I will say that after a couple of weeks of the dirt being in with the compost, leaves etc. that the dirt is starting to turn to healthy soil! It is a dark rich color that is retaining moisture but crumbly, not the thick hard dry clay. Im assuming that if I continue to mulch on top of that with good clean mulch that next year I wont have this issue. Thanks again for the good advice! No worries about the location, I tend to forget about it since we come to the forums a lot. Good luck with your house, we just sold ours by ourselves last year amidst a lot of other things, at least you don’t have to do open houses anymore!

g'day bliz,

i know you directed your question to toby, but can anyone wade in?

those weeds as has been said could generate from anywhere even the soil you added in or maybe not enough cardboard/newspaper laid down first? if you mulch over them (up to 8"s) when they emerge then that will bring control in, there after, we simply pull any weeds we don't want (weeds can be usefull plants in permaculture gardens)as they emerge and tuck them under the mulch as extra nutrient. due to mulching practises volunteers have hard time in our gardens.

we use spent mushroom compost from the farm as or preferred medium for new gardens and with this product we can plant the garden right away.

anyhow for now if you wish you could check our bale garden and raised beds processes on our site:

http://www.lensgarden.com.au/straw_bale_garden.htm

len

Cheers len! I always welcome more information so by all means fire away! Ill check out the links.

i have dug a gazillion wheelborrow loads of quackgrass from my gardens that I have reclaimed..what would you do with it..

I'm so afraid to use it anywhere as it probably will never really die.

right now i have it in a huge pile near my woods..and i really hate to just leave it there..suggestions would be greatly appreciated

g'day benda,

could it be dreid roight out then considered dead and then used in garden with good cover of mulch? i'd be looking at rough spreading it not too far and wide in a food tree area maybe or some sort of tree area then covering it with a good cover of newspaper and then cover with at least 8"s of mulch. do't reckon on much coming through that. we get good success over nut grass that way, prior to starting garden cut low cover with at least 40 sheets of newspaper overlapped about 2"s then lay on the mushroom compost 1' thick (yes 1 foot)with 8" mulch on top.

len

Hello everyone,

I don't want to be too off topic but my question is whether I should sheet mulch or not. I live in a city and plan to break concrete to expose about 290 square feet of soil (29' by 10'). I didn't know about Permaculture last fall so, I missed the chance to lay down a sheet mulch for winter. It is now March and things are warming up, but I don't know if, after freeing the soil, I should throw down a sheet mulch or jump right ahead to sowing white clover as a ground cover, which I would like to keep as my regular mulch. Should I sow the clover into the mulch? Also, I have yet to build a raised keyhole bed for my herbs and annuals and greens (with the leftover concrete from the jackhammering), would I do this at a later date or should sheet mulch go on top? I hope my questions aren't too dizzying, but I am new to gardening and permaculture techniques so I would really appreciate any tips.

Thanks!

Dan L wrote:
Hello everyone,

I don't want to be too off topic but my question is whether I should sheet mulch or not. I live in a city and plan to break concrete to expose about 290 square feet of soil (29' by 10'). I didn't know about Permaculture last fall so, I missed the chance to lay down a sheet mulch for winter. It is now March and things are warming up, but I don't know if, after freeing the soil, I should throw down a sheet mulch or jump right ahead to sowing white clover as a ground cover, which I would like to keep as my regular mulch. Should I sow the clover into the mulch? Also, I have yet to build a raised keyhole bed for my herbs and annuals and greens (with the leftover concrete from the jackhammering), would I do this at a later date or should sheet mulch go on top? I hope my questions aren't too dizzying, but I am new to gardening and permaculture techniques so I would really appreciate any tips.

Thanks!

Dan, funny enough I just bought a house in San Jose CA and rented a jackhammer to remove 4" concrete slab. There was dirt under it but I'm sure a few inches down had to be some soil. I just took a garden hoe and scratched the top few inches up, threw a mix of cover crop in (clovers/vetch/buckwheat) and they've been coming up since the start of this week. (sown about two weeks ago).

I should also say I don't know what I'm really doing and I'm new to permaculture. This was an experiment for me.

Jovialgent:

Cool! I am leaning more towards doing what you did myself. The more I read about the benefits of white clover the more I am tempted to just rake the new soil and scatter a bunch of seed. I like the idea of sheet mulching but I live in NYC and don't have a car, so getting all the materials for sheet mulch is a real task. I have been reading up on Masanobu Fukuoka and it has given me courage, as have you! So, I guess that will be my move and then to interplant by spreading the cover apart. Thanks for the feedback!