Sheet Composting

 My partner Jeff Ball bought the mother of all juicers and I am first in line when he’s ready to dump the leftover pulp. That finely processed mush of vegetables and fruit is perfect for enriching the soil in my vegetable garden.

I just dig a hole in the soil, dump in the gunk, and cover it up. Mother nature in the form of earthworms and soil microbes does the rest. They feast on that vegetable matter and quickly turn it into first class compost and then to humus that’s in place and ready to go to work at planting time.

Post Hole Digger Trick

An easy technique is to use a post hole digger to dig your hole quickly and smoothly.  Put in the gunk and empty the soil held by the post hole digger back into the hole. click here for examples of post hole diggers.

Called sheet composting, I’ve been using this method of enriching the soil for many years. In late summer and fall I collect fruit and veggie scraps, liquefy them in my blender and dump them in the garden. I even add leftover coffee along with the coffee grounds.

Sheet composting is a great way for folks who have no place for a compost pile to build humus rich soil.

The great thing about sheet composting is you can include food such as sour milk and spoiled yoghurt that should not be used in a compost heap. And don’t overlook leftover cereal and cooked grains and beans.

It’s important to liquefy the foodstuff and bury it because; the slurry breaks down quickly, does not smell and does not attract animals.

When processing be sure to add enough liquid. The consistency should be that of a milkshake. Work in short bursts so as not to overpower the machine.

Consider picking up a used blender or food processor at a yard sale or the Salvation Army and dedicate it to making liquid compost.

When I’m feeling ambitious I include corncobs in the recipe, because they’re full of nutrients. In the old days farmers recycled corncobs by grinding them up to make food for their animals. My Vita Mix blender has an industrial strength motor and can process dense chunks of material, so using a small hatchet I chop fresh corn cobs into small chunks and add them to my potion. You could do this in a regular blender but the cobs must be chopped into very small pieces before adding them to the container.

Egg shells are a great source of calcium, but take a long time to break down so I make sure they are pulverized before adding them to the soil.

Sheet composing is best done in soil that lays fallow over the winter. However, in spring the enriched soil can be moved and used in all parts of the garden and landscape.


Sheet Composting           


            Sheet composting is a procedure for disposing of yard waste without building a compost pile.  By means of several different techniques it involves spreading the waste material directly on the soil to decompose there.  Mulching is nothing more than sheet composting.  Organic materials used as a mulch slowly breakdown and are pulled into the soil by the microlife of that soil.  This is sheet composting at its simplest.  It calls in question the advisability of using mulching fabrics under organic mulch, because these textile products obstruct or slow down the entry  composted mulch into the soil.  For centuries farmers have been leaving organic materials and manures on their fields to break down and be plowed back in.  That is sheet composting. 


[Photo - Showing someone spreading organic material on to garden bed]


            Sheet Composting On The Surface -- The most common method of sheet composting involves spreading and layering organic material over a garden area of some kind, and tilling it into the soil with a hoe, spade, or roto tiller. Fall is the best time of year for surface composting, when the garden has stopped producing and the soil is cleared of plants.  It is possible to do this in the spring also, but wet soil may make it more difficult. 


            Almost anything that goes into a compost pile can be sheet composted.  Fallen autumn leaves provide the ideal organic material, as they easily till into soil and rapidly decompose.  Grass clippings, manures, garden and kitchen wastes (except meat scraps) are also good additives.  While you can layer these materials just as they come, it is easier to work them into the soil if they have been shredded or chopped first.  Usually, its a help to have some kind of holding bin where the organic materials can be accumulated until it is the right time to shred and spread them.


            To sheet compost in the fall spread a 4 to 6 inch layer of organic waste on the garden's surface.  To do it in the spring reduce the layer to 2 to 3 inches and spread it approximately 3 to 4 weeks prior to planting time. Many gardeners choose to spread some granular fertilizer at the same time they set out the waste materials.  This helps get the decomposition process cooking.  A compost activator product applied at the same time will insure sufficient microbial activity to process the waste.  Then work all this material into the soil.  In vegetable gardens a tiller is the best tool.  In flower beds where perennials and bulbs must not be disturbed work in the organic material carefully with a spading fork or hoe.


[Photo - showing roto-tilling material into soil]


            If you sheet compost in the fall, the organic materials will have pretty much decomposed and blended into the soil by spring planting time.  Material put in early spring will not be so thoroughly decomposed, but after 4 or 5 weeks it is safe to plant seeds and set in plants.  In either case, you'll notice a marked improvement in the soil structure; it will looser and more crumbly.  Its capacity for moisture retention will increase, and it will have stored in it nutrients released from the decomposition ready to enrich the plants and seeds. All these are  the benefits of using regular compost, but there are fewer steps involved in sheet composting. 


            Sheet composting with double digging -- Double digging a garden bed is a very thorough and somewhat rigorous method for preparing the soil in a garden in the fall or spring.  It is possible to incorporate sheet composting into this process. Start at one end of the bed and dig a trench across the bed about one foot wide and one shovelful deep.  The normal procedure is to then take a garden fork and loosen the subsoil at the bottom of this trench, then to step back a pace and dig a line of topsoil from across the bed over on to the newly loosened subsoil.  Following this procedure step by step down the length of the bed produces very light and loosened soil 12 to 18 inches deep over the entire area, ideal for growing vegetable and flowers.


[Line drawing  - Showing double digging technique - probably three or four drawings]


            Gardeners with lots of organic materials go one step further while double digging their beds.  After loosening the subsoil in the trench with a fork, they add a 2 to 4 inch layer of organic material before covering it with the next line of topsoil.  This added step effectively raises the bed a few inches above the surrounding area which is an advantage for better soil drainage.  The added organic material slowly breaks down, leaving the soil underneath the topsoil loose, friable, and more fertile because of this sheet composting method.  While this technique involves considerable physical effort, it need only be repeated every two or three years to maintain wonderful garden beds for planting.  For best results, do this in the fall to give the organic material time to begin decomposing so it is not competing for nitrogen with young plants in the spring.


            Sheet composting with post hole digger -- If most of your garden beds always have plants in them, making surface composting difficult or impossible, use a posthole digger to do sheet composting.  With a posthole digger you can dig a 6 inch wide hole as deep as 12 inches in a very short time.  Deposit organic material (preferably shredded or chopped) into a series of these holes in areas near shrubs and perennial plants over a period of time.  Dig a hole, bury the yard waste, and refill the hole.  When there is more waste, dig another hole and fill it.  This technique is especially attractive for disposing of kitchen waste.  It is not appropriate if you have large volumes of material to deal with. 


[Photo - Someone with post hole digger digging holes in bed]


            Sheet composting with liquefied garbage -- Kitchen wastes, except meat products, can be easily turned into liquid form for use in sheet composting.  An industrial strength blender such as a VitaMixer(TM) will reduce rinds, peelings, broccoli stems and other garbage to a puree that is easily introduced directly into the soil to decompose there.  A fair number of homeowners across the country have been liquefying their garbage for years, but instead of adding the material to a compost pile, they pour it   onto their garden beds, around trees and shrubs, and along hedges, usually under some mulch.  They report that there are no odors or pest problems and the technique eliminates the need for any fertilizer where the liquid garbage has been applied.  The garbage in this form is pulled into the soil by the soil's creatures within about two weeks.  Try this liquefied product in holes dug with the posthole digger. 



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