LSU AgCenter Horticulturist
It is a pity what generally happens to leaves that fall from deciduous trees this time of the year. Most people rake them up, put them in bags and then place the bags on the curb to be picked up with the trash.
There’s no need to throw away this valuable resource. You can recycle these leaves – either back into the landscape as mulch or through the process of composting.
Returning this organic material to the garden maintains natural biological cycles and is an ecologically sensible means of recycling organic waste. 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 for mulch. You can just rake them up and put them into beds around shrubs. The layer of leaves should be about 4 inches thick. Think of the money you will save not having to purchase mulch. You also can rake up the leaves and put a 2-inch layer around bedding plants in flowerbeds or vegetable plants in the garden. If you pick the leaves up using a mower with an attached bag, the chopped leaves are particularly nice as mulch.
Compost is used primarily in bed preparation to improve the soil. Producing it yourself saves the cost of purchasing compost, peat most or other organic matter for bed preparation.
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 feet by 3 feet by 3 feet to 5 feet by 5 feet by 5 feet in size. Anything smaller will not decompose as well, and larger piles are more difficult to turn.
You can compost just by stacking organic matter in a pile, but most gardeners prefer to enclose the pile in a bin. 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 or fencing wire bent into a circle and fastened with a few pieces of wire is inexpensive, easy to build and works well.
You can create compost simply by piling up leaves and other organic matter and allowing natural decomposition to take place. This is sometimes called passive composting. It’s not really complicated, although using this method takes a while. Be sure to keep the organic matter moist. Depending on circumstances, it may take six to 12 months for the material to compost fully.
Typically, composting uses various techniques to speed up the natural breakdown of yard waste. Raw organic material is converted into compost by the action of fungi and bacteria. In active composting, you can do things to make these organisms work faster and more efficiently.
These fungi and bacteria require adequate nitrogen, oxygen and moisture to decompose organic matter rapidly. The active composting process attempts to provide these requirements. And the better job you do, the faster the process will occur. Shredding or finely chopping materials to compost 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 provide the bulk of what is being composted. Apply a light sprinkling over each 8- to 12-inch layer of organic matter as the pile is built.
Besides fallen leaves, you can compost a variety of organic materials, 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 and 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 openings that allow air to move in and out. Turning the pile occasionally is labor intensive, but it does ensure the pile is well aerated and speeds decomposition.
During dry weather it may be necessary to water the pile to maintain adequate moisture levels. Dry organic matter will not decompose. The pile should stay moist but not be 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. The use of special compost starter or compost-maker products is not really necessary.
As plant 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 well moisture and oxygen levels were maintained.
Two to six months is typical for a complete composting cycle, but it can happen much more quickly.