VERMONT — Effective July 1, organic food scraps will be banned from landfills. Although many recycling centers and trash haulers will accept food waste, your best option may be to start a backyard compost pile.
Compost improves garden soil by increasing its organic matter. This, in turn, improves soil drainage. Organic matter is especially beneficial in heavy clay or light, sandy soils as it reduces soil crusting and helps soil hold water and nutrients.
Microorganisms decompose materials to make compost. To do their work they need carbon sources for food and nitrogen for proteins. They are most effective when the carbon to nitrogen ratio is an average of 30 to one by weight.
You don’t need to weigh what you add to the compost pile. Just be aware of approximate amounts that you’re adding. Generally, two to three parts (by volume) of brown to one part green materials works well.
In general, coarse woody materials (sawdust, leaves), which composters refer to as “browns,” are high in carbon. Moist, dense materials (grass clippings, manure, food and non-meat kitchen scraps) are high in nitrogen. These are the “greens.”
Too much carbon material, and the compost pile will decompose slowly. Too much nitrogen and you may smell ammonia gas.
Plant materials and products that are easy to compost, and which generally decompose most rapidly, include egg shells, coffee grounds, pine needles, fruit peels and rinds, shredded paper, sawdust, straw (not hay, which often contains weed seeds), vegetables, tea bags, leaves, wood ashes and wood shavings.
Materials that are slow to decompose and may take two years to break down include coarse wood chips, branches, corncobs, corn stalks and nut shells. Breaking these materials into smaller pieces and adding high-nitrogen materials will speed up their composting.
You can use any plant material that’s not diseased, doesn’t contain mature weed seeds and hasn’t been treated with pesticides or herbicides. In addition, you can compost non-meat kitchen scraps but skip any meats, animal fats or milk products as these will attract pests.
Some gardeners also add an “activator” to help the microorganisms, which provide a source of protein and nitrogen. You can buy this commercially, or use alfalfa meal from garden or feed stores.
Several types of compost bins or tumblers are available for purchase, or you may make your own from wooden pallets stood on end and tied together. Or just make a pile.
To make compost, add five to eight inches of browns, two to three inches of greens and then a layer of soil or composted manure one to two inches deep. Moisten each layer. Repeat these layers until your pile is high enough or your bin is full.
Turn the pile weekly, adding moisture during prolonged dry periods. Turning the compost helps to aerate and improve air circulation in the pile, which in turn helps reduce acidity (pH).
The microorganisms that break down materials prefer a neutral to slightly acid environment.  Many materials you add to compost are acidic, so a sprinkling of lime will help raise the pH, or in other words, reduce acidity. Just don’t add too much lime (or wood ashes, which serve the same purpose).
The ideal temperature in the interior of a compost pile is about 120 to 130 degrees Fahrenheit. You can measure the temperature with a compost thermometer — basically a dial on a long rod — available at garden supply stores or online.
Compost piles are simple to make, but it does take time for the process to work. Be patient. In cooler climates and with small piles or bins as in most home gardens, it may take up to a year for compost to be ready.
 But your soil will benefit in the end. And you’ll be recycling all those great organic materials into your garden rather than into a landfill.
Leonard Perry is Horticulture Professor Emeritus at the University of Vermont.