Saturday, September 24, 2011

Sheet Mulching for Food Forest Farming


First portion of the sheet mulched area; much more ground to cover
I'm totally revamping my lawn and garden areas, moving away from the fairly traditional ways I've always planted things, and more into what is considered "food forest farming". Part of the changes include getting rid of more of the area I have to mow, and moving the food garden areas up higher away from the creek to avoid flooding. It also entails integrating fruit and nut trees with vegetables, bulbs, flowers and herbs into "guilds" that supply the needs of each other. It's a very ambitious project, and cannot be done in just a year or two.

Unfortunately, the new area is all green stuff called "lawn" (I have way too much lawn to maintain anyway!) I have neither the stamina to dig all the grass out, nor the money to hire it done... and I do not want it plowed, which only brings up more weed and grass seeds to deal with in subsequent years.

So I'm starting with deep sheet mulching (per Gaia's Garden) an area about 24' x 50' if my energy holds out. Next year I hope to double it in size. The general idea is to put down a layer of cardboard or newspapers, then cover with about a foot of mulch and wood chips. On top of that, I'll put a couple of inches of topsoil. By spring it should have somewhat decomposed and be ready to plant at least a few things.

My sister can get used cardboard where she works; all I have to do is split the boxes and remove any staples and the tape which will not decompose. 

Partially mulched starting area of 16' x 24'

I bought several bales of alfalfa hay because: 1) it was the same price as straw bales, and 2) straw bales have lots of grass seed heads in them. I'm hoping the alfalfa seed heads in these bales won't be as much of a problem as the seed heads in straw. I made the mistake with straw once before. It was mostly grass/grain seed that sprouted the next spring, but just one single mature Redroot Pigweed that could have been in any bale would contain at least 35,000 seeds that are viable for 60 years. Regardless, I sure had a mess of weeds from the straw and hope not to repeat it.

Plus, alfalfa is a legume containing lots of nitrogen, and is also high in protein, calcium, a few other minerals, and vitamins B, C, E and K. That should help feed the microbes and other soil organisms that will break the sheet mulch down over winter!

I plan to broadcast  Greensand over the alfalfa to add some trace minerals, which will also help loosen the heavy clay underneath the cardboard once the cardboard has all decomposed. (Greensand is generally Broadcast @ 50-100 lbs. per 1,000 square feet.)

After the alfalfa has had a few days of rain on it (the weatherman says this week), I will probably have to add another layer of alfalfa as it has settled. Then I'll add a layer of willow chips on top of the alfalfa. The chips are left from last year's tree work, so they are partially broken down already. I also have some of my own garden compost to add, but not nearly enough to cover much of the entire area. Stubbornly, I refuse to buy bagged compost because I don't trust what might in it... so what I have from my garden will have to do.

I will post more about this big project as I work on it, plus ideas to hold water for this new area. In the meantime my time is parsimonious, between starting this new garden, making the garden hoops with row cover for fall plants, and the house projects... all of which need finishing before cold weather.

Do I sound overwhelmed? I am!!


  1. Shouldn't be trouble with alfalfa seeds, although weeds in it are another story. Usually.. they try to aim to do the first cutting when about 10% of the alfalfa buds open. They aim for that because of protein content, leaf growth, etc.
    First cutting.. is less of a problem with weeds in higher quality bales. The bales from later cuttings it can be. They grade the bales on when it was cut, the content (as in replanted field has more alfalfa vs one that was planted 3 years ago or more) etc. to judge the quality. Alfalfa is one of those goofy plants that just won't play nice with younger siblings.. mini chemical warfare to keep it from crowding itself out. Usually it is planted as a mix with another crop (ours is with clover, which is common), or they drill and plant into fields.

    Straw.. is the dried stalks of a cereal crop. As in that crop matured.. so did the weeds growing next to it.

    Nitrogen is rather fleeting. Alfalfa is a nitrogen fixing plant, but nitrogen content drops when it dries. Most of it's impact is when it is living and working with it's bacteria buddies. Protein content also can vary by a bit according to what stage they cut the alfalfa at (before bloom break is higher).

    Hope that is useful. Best wishes for your garden!!

  2. Thanks Anne. I figured the nitrogen would be minimal since this is not "planted" alfalfa.

    Interesting about the cultivation of alfalfa, though. My only experience with it was buying it many years ago when I raised Arabians. My supplier was growing it in an experimental program for NCSU.

  3. Mike McGroarty recently sent an email describing how to convert old trampolines into hoop houses by taking the round part of the frame and cutting it in half. Then he pounds steel posts into the ground to both make the hoop house taller and to firmly anchor it. He used the straight parts of the trampoline between the hoops to stabilize and hold plastic on, and ran wide boards along the bottom.
    I use wheat straw, but let it set for a couple of seasons and get totally saturated and dry out a few times to kill the weed seeds. For some reason, Colorado potato beetles do not like wheat straw, so I successfully use it around potatoes.
    Be on the lookout for GMO alfalfa, the govt allowed it to be planted. Gross.


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