About the Zoo | Employment | Volunteer | Press

Backyard Composting

By Paul Reid, Botanical Educator

The Louisville Zoo received a partial grant from the USDA Forest Service Urban and community Forestry program in cooperation with the Kentucky Division of Forestry, for the Zoo to continue developing new botanical education programs. The grant funded a part-time educator to help increase public knowledge about backyard habitats, composting, the importance of trees and plants in urban habitats, and to help create and implement new curriculum.

When it comes to backyard composting, many residential gardeners imagine a messy, timeconsuming and space-occupying addition to their landscape. In reality, processing organic waste on your own can actually save time, money, and natural resources by reclaiming the many tons of material that end up in local municipal landfills. By understanding how we can take advantage of the natural process of decomposition of matter, our gardens and environment will be healthier, and fewer fertilizers will have to be purchased to replace nutrients that are thrown away.

The breakdown of organic matter is a process that in nature is done by worms, insects, bacteria, and fungi already present in the environment. Composting is just supplying the key ingredients in the proper amounts to activate the break down of organic materials into usable nutrients. These can then be returned directly to the garden in the form of an organic, slow-release fertilizer. Adding compost also improves the structure of the soil, making it drain better, hold moisture and suppresses the growth of weeds.

One of the easiest ways to save time and energy in the garden is to use a mulching mower. Mulching your grass clippings reduces them to fine pieces that dissolve, returning nutrients back into the lawn. Adding an occasional bag of saved grass clippings to your compost pile also facilitates the process of decomposition. Weeds can be used, but be sure to add them before they go to seed or  you’ll be putting the weeds back into the garden at some point.

Another great source of green matter is the scraps of vegetables and peelings that come out of the kitchen. (Never include meat scraps in your compost, as this can invite unwanted animal guests to your yard.) The other element of the compost pile is brown matter in the form of raked leaves, twigs, branches, and even shredded newspapers.

There are two kinds of composting. The first is a cold, slow, and passive process in which the  green and brown matter is put in a pile to allow decomposition to take place. This slow process is the  easiest to do, as the material is added gradually, but the process may take months or perhaps a year to create a usable result.

The second kind of composting is a hot, fast, and more active process that can create a usable product for your garden in a matter of weeks. The hot compost pile is created by first layering the green and brown matter much like lasagna, adding moisture as needed, and most importantly turning or aerating the pile.

Whether you use a slow to-rot pile or a fast-layered one, a compost bin is a useful tool to contain your material and make it easier to turn the pile. There are many varieties of bins that can be purchased.

Simple bins can be constructed using a piece of hardware cloth clipped together to form a circle. In order to turn the pile, the bin is unclipped, set up next to the pile and the contents transferred back into it. The multiple or two-bin system can be constructed using cement blocks or a constructed wood frame.

Regardless of what method you use, composting at home can, in the long run, save time, money, and our landfills, while returning many needed nutrients to the garden. There are many great books on composting and numerous websites that offer greater detail about the process of decomposition. On your next visit to the Zoo, stop by the MetaZoo Education Center and see the demonstration compost exhibit behind the building.