CREATE YOUR OWN COMPOST
If you have a mountain of leaves to dispose of this autumn, here’s a way to turn it into a molehill of nice dark compost to use around your shrubs and flowers. Ordinarily, composting is a fairly slow process. But you can speed it up by controlling three things—air, water and surface area of the organic material. (making compost bins l purchasing bins)
Some leaves, such as those from locust trees and some maples, are small and fine enough to go into the compost pile as is. However, locust stems and tougher leaves from other trees such as cottonwood, oak and catalpa need to be chopped. You can use a chipper/chopper or run your lawnmower back and forth through and over the leaf pile. Catch chopped leaves with a bag attachment. You can also chop and add other green plant materials, and mix in grass clippings to add moisture and nitrogen.
The simplest way to compost leaves is to pile them in a corner of the yard to about four feet high. They’ll decompose much faster, however, if you allow air to penetrate the pile. Start with a bottom layer of coarse material such as twigs, hedge trimmings, sunflower stalks or raspberry canes. Then add leaves in layers, interspersed with modest amounts of the coarse material.
Add water to the pile until chopped leaves feel like a well-wrung sponge. Too much water, more than 60 percent, displaces the air and kills the microorganisms that are decomposing the leaves. If there’s too little water, under 40 percent, microorganisms can’t function. Having some coarse material in the pile allows rainwater or water from a hose both to penetrate the pile and to drain out of it.
TURNING UP THE HEAT
The pile should heat up in a few days as leaves start decomposing. You may even see steam rising from it on a cold morning. To keep decomposition going at top speed you need to turn the pile over so that outside material moves to the inside and vice versa. After a few days turn it again. The pile will begin to get smaller as leaves decompose. Compost happens! If you don’t turn the pile compost will still happen, just more slowly. In fact, if it’s getting cold out don’t turn the pile, as too much heat is lost. Wait until spring to turn it again.
Not everyone cares to have a large pile of chopped up leaves in their yard and some municipalities forbid it. Simple structures can help corral the plant materials. One of the simplest is a circular bin of hardware cloth. A 12.5-foot (minimum) by 36-inch piece of half-inch hardware cloth can be bent into a cylinder and fastened together with wire. Just set it where you want it and dump the plant materials into it. To turn the pile, lift up the wire cage and set it down next to the pile. Take materials from the outside of the pile first and put them inside the wire cylinder, followed by inside materials. A wider cylinder filled up will work more efficiently than a smaller one.
You can make a similar structure from discarded wooden pallets. Set three pallets into a square and fasten at the corners. Leave the fourth side open for ease of access. Add one or two more squares , using additional pallets, next to the first square to receive the turned pile(s). An advantage of this system is when you turn the compost pile into the second square you can start a new batch in the first one.
You may decide to build a fancier structure, but remember to keep easy access to the compost pile and to have lots of open space in the side walls so air can get in.
For additional information check the University of Minnesota Extension Service web site at www.extension.umn.edu and type “compost” in the search box at the top of the home page.
Jennifer Porwit, Master Gardener, Ramsey County