Richard Bogren | 12/2/2016 3:01:14 PM
By Dan Gill
LSU AgCenter Horticulturist
(12/02/16) What we generally do with leaves that fall from deciduous tree this time of year is a shame. Most people rake them up, put them in bags and place the bags on the curb to be picked up with the trash.
There is no need to throw away this valuable resource. You can recycle these leaves back into the landscape as mulch or through the process of composting.
Returning these organic materials to the garden maintains natural biological cycles and is an ecologically sensible means of recycling organic waste generated by your landscape. It also saves your community money spent collecting and disposing of waste and reduces the amount of waste going into your landfills.
It’s easy to use leaves as mulch. You can just rake them up and put them in beds around shrubs in a layer about 3 inches thick. Think of the money this will save not having to purchase mulch. You can also rake the leaves and apply a 2-inch layer around bedding plants in flower beds or vegetable plants in vegetable gardens. If you pick up the leaves using a mower with a bag attached, the chopped leaves make nice mulch.
Compost is used primarily in preparing beds. Incorporating a generous amount of compost into the soil during bed preparation helps plants grow better. Producing it yourself saves the cost of purchasing compost, peat moss or other organic matter.
Compost piles should be located in a convenient but out-of-the-way location. A source of water nearby is helpful. Make the pile about 3-by-3-by-3 feet to 5-by-5-by-5 feet in size. Anything smaller will not allow good composition, and larger piles are more difficult to turn.
Typically, composting uses various techniques to speed up the natural breakdown of yard waste. Fungi and bacteria convert raw organic material into compost.
You can compost just by stacking organic matter in a pile, but most gardeners prefer to build the pile in an enclosure. Although a number of commercial bins are on the market, you can make your own very easily. A 15-foot-long piece of hardware cloth, chicken wire or fencing material bent into a circle and fastened with a few pieces of wire is inexpensive, easy to build and works well.
You do passive composting simply by piling up leaves and other organic matter and allowing natural decomposition to take place. It’s not really complicated, although using this method takes a bit of time. Be sure to keep the organic matter moist. Depending on circumstances, it may take six to 12 months for the organic matter to fully decompose.
Active composting means doing things to make the fungi and bacteria work faster and more efficiently.
These organisms require adequate nitrogen, oxygen and moisture to decompose organic matter rapidly. The composting process attempts to provide these requirements, and the better job you do the faster the process will occur. Shredding or finely chopping materials also greatly speeds up the process.
Adding a commercial fertilizer or an organic fertilizer, such as blood meal, that contains nitrogen will encourage rapid, thorough decomposition when brown leaves are the bulk of what is being composted. A light sprinkling of fertilizer is applied over each 8-to-12-inch layer of organic matter as the pile is built.
Besides fallen leaves, a variety of organic materials can be composted, including grass clippings, shredded hedge clippings, raw vegetable and fruit trimmings and coffee grounds from the kitchen, dead houseplants and old flower arrangements.
Never put cooked foods, grease, meat, seafood scraps, fat or dog or cat droppings in the pile. It is also best not to put into the compost diseased plants or weeds that have set seed.
Oxygen is provided by enclosing the pile in a bin that has sides with a lot of ventilation to allow air to move in and out. Turning the pile occasionally is labor intensive, but it ensures the pile is well aerated and speeds decomposition.
During dry weather it may be necessary to water the pile to maintain adequate moisture. Dry organic matter will not decompose. The pile should stay moist but not constantly soggy. A pile that stays too wet does not contain enough oxygen and may produce sour odors. If this happens, turning the pile will correct the problem.
You can throw an occasional shovel full of soil into the pile as you build it to supply the microorganisms that carry out the decomposition process. Using special compost starter or compost-maker products is not really necessary.
As materials compost they lose more than half of their volume. When compost is ready for use, it should be dark brown and crumbly with much or all of the identity of the original material lost. The time it takes to finish varies, depending on the materials used, how finely they were chopped and how moisture and oxygen were maintained. Two to six months is typical, but it can occur much faster.
Backyard compost bins can be made simply by putting wire fencing in a circle or square. Photo by Dan Gill.
Leaves can be placed in wire bins for making compost that can be used later in the landscape. Photo by Dan Gill.
Finished compost should be dark brown and crumbly with much or all of the identity of the original material lost. Photo by Dan Gill