Composting Yard Waste Basics

Turning waste into compost

Brian Jervis: Ask a Master Gardener Saturday,

April 30, 2016

Q: I would like to compost my grass clippings and some of the other material from my gardens, but I am not sure how to get started. Suggestions? Jim, Broken Arrow.

A: Many people dutifully recycle paper and other approved wastes by placing them into the city's recycle bins but send their yard wastes to be burned — wastes that are beneficial if recycled. These materials are best added to a compost pile, and when fully composted, they produce superb additions to garden beds, either tilled in or used as a mulch.

Limitations to composting may be lack of information about the process, space for a compost bin and a determination to recycle.

The OSU fact sheet “Backyard Composting in Oklahoma” will supply the information needed to get started. This fact sheet explains the composting process, including what can be composted, how to build a bin and what can go wrong. There are also many excellent websites on composting, including the city of Tulsa’s website.

One first needs to identify a space that can be devoted to a bin. Many materials are available to build a bin, such as various types of stone, treated lumber, old wood pallets and wire fencing. These structures keep the materials together. However, some people simply make a large pile of materials to compost, although effort must be made to keep it contained.

Several versions of drums are used for composting. These may be bought or made from a plastic trash can. The commercial ones are expensive but work well and are tidy. Cornell University Extension's website has a list of suppliers for these drum composters.

It has been shown that one needs a combination of two types of materials for composting. These consist of brown materials, which are high in carbon, and green wastes, which contain the nutrient nitrogen. The browns are typically fallen leaves, straw, paper and wood wastes — chips and sawdust. The greens are often lawn clippings, green garden trimmings and kitchen scraps. If a pile has only brown material, a substitute for greens is a handful of nitrogen fertilizer.

Animal manures may also be added but only from plant-eating animals (herbivores). Cat, dog and human wastes should not be used. Also, one should not add any dairy products or fatty wastes from the kitchen.

The composting process is performed by many different types of bacteria and fungi. They decompose, or break down, the materials into garden-friendly organic matter, which is compost. These microorganisms need oxygen, water and nutrients to do their job. Done properly, the decaying process produces heat, and the core temperature may reach 140 degrees and will kill many, but not all, of any disease and insect pests. It is important to keep the pile wet and turned often. The more it is turned, the more oxygen is able to penetrate the pile and the faster it will compost.

Garden tips

§  After moving potted plants from inside to outdoors, irrigate the pots with 2-3 pot volumes of water to remove salts that may have accumulated from fertilizers.

§  Spring-blooming bulbs are best fertilized in fall and late winter when leaves emerge. After blooming, they go dormant and cannot use fertilizer applied at that time.

§  When Bermuda and Zoysia lawns are fully green, begin applying fertilizer. Bermuda grass will benefit from 2 to 5 pounds of nitrogen fertilizer per 1000 square feet in divided applications over the summer. Zoysia lawns need about half that amount. Don’t use a phosphorus-containing fertilizer unless a soil test indicates a need.