When gardeners talk about amending the soil, they’re talking about adding materials that will improve drainage and soil texture and increase nutrient levels. Gypsum, lime and sulfur are examples of non-living mineral amendments. Composts and humus are made from living organisms (organic materials derived from plant and animal residues) that are in different stages of decomposition. The bacteria and fungi in composts feed on plant and animal residues in the soil as they decompose; humus has finished decomposing.
Both humus and composts are full of plant nutrient elements. In fact, soil that is regularly well-amended with compost and humus may need little or no additional fertilizers. Beneficial bacteria and fungi as well as earthworms contribute to soil fertility. The highest numbers of beneficial micro organisms and earthworms are found in the top 10 inches of soil, in the root zones of plants.
Great quality compost starts with the fruits, vegetables and eggs in your refrigerator and the coffee and tea in your cupboard. Every day we throw fruit and vegetable pits, peelings and skins, tea leaves and bags, coffee grounds and unbleached paper filters, and eggshells into the garbage-those plant and animal residues can be used in your garden to improve your soil’s health and structure.
The idea of composting kitchen waste makes many people uncomfortable. But when done right, the compost pile will not be slimy, smelly or attract insects. (Although it may attract rats, raccoons and other vermin).
Find a place in your garden where you’ll have space to set up two 2-by-2-foot piles of kitchen compost. The kitchen scraps (no bread, no meat, no grease, no bones) of a family of four can fill a one-gallon kitchen compost pail every day. It will take at least two weeks for 14 gallons of compost to make a 2‘ x 2‘ pile, since the kitchen waste will start decomposing and reducing in size immediately. Start the pile with a bag or several buckets of finished compost or humus. Add a bucket or two of leaves every week to increase carbon levels. Chop the kitchen waste into 1 or 2-inch pieces, turn the pile every couple of days incorporating some of the finished compost as you turn (I keep a shovel nearby for the chopping and turning), and keep the pile moist but not wet. Turning the pile often and covering the top with finished compost or dead leaves prevents insects from laying eggs and masks any smells. If you have a problem with vermin getting into the pile, place chicken wire over the top and anchor it with stakes or pins.
Stop adding kitchen waste when the pile remains larger than 2 by 2 and start another pile next to the first. It should only take 2 to 3 weeks with no additions for the compost in the starter pile to turn dark brown and crumbly. When you can’t see any pieces larger than than a grape, you can turn the finished kitchen waste compost into planting beds or use it as a fertilizer.
Send Elinor Teague plant questions at firstname.lastname@example.org or email@example.com (“plants” in the subject line).