Andrea L. Beaudin
Want to build up your soil? Tired of dragging bags filled with kitchen trash like coffee grounds, egg shells, and banana peels to the curb each week? How much do you spend each year on paper lawn bags that you fill with leaves and grass cuttings—and then pay to have those bags taken away?
Let it rot! Your lawn and garden will be the better for it, and you’ll be doing your bit to decrease the load on landfills, too!
According to the Environmental Protection Agency, “yard wastes account for nearly a fifth (over 31 million tons) of all garbage generated in the
What can be composted?
If it can decompose, it can be composted. Prime choices include plant-based kitchen scraps such as potato peels, citrus rinds, coffee grounds, that salad you forgot in the back of the refrigerator, that bouquet of flowers that’s no longer looking too cheery—you get the idea. You can also use egg shells, wood ashes (from real logs, and use sparingly, as they can raise the pH of the compost, and your soil), yesterday’s paper (no color inks or glossy-coated magazines), paper towels, dryer lint, even hair.
While pine needles can be used in compost piles, they tend to be very acidic. You’re better off using them to mulch strawberries, blueberries, hydrangeas, or other acid-loving plants.
Most of what is composted falls into one of two groups: “browns” and “greens.” Browns are typically dry plant material that is higher in nitrogen; think grass clippings, dried leaves, straw, old newspapers, stale cereal, twigs, ashes, and sawdust (preferably from untreated lumber). Greens are fresher and wetter, and are, as you may guess, usually green: kitchen scraps, weeds that haven’t gone to seed, and the like.
Size does matter; just like a block of ice melts more slowly than several smaller ice chips, the bigger something is, the longer it will take to decompose. If you want to compost logs or old watermelons, be prepared to wait a bit longer. To speed things up a bit, increase the surface area available to the microbes that power the composting process by chopping or even simply nicking the surface.
What cannot be composted?
Although a properly built compost pile will reach temperatures high enough to kill most pathogens and weed seeds, you would probably want to avoid composting anything that could spread diseases to you or your plants. This means no cat or dog feces (though most other manures are fine) and no plant cuttings that are diseased or infested by insects. Meat and fats decompose much slower than plant matter, and may attract rodents, so it is recommended that they be avoided. Studies have shown that while many pesticides break down during the composting process, certain herbicides (chemicals used to kill plants) may not break down as easily, and could result in a product that actually hinders—not helps—your garden. Similarly, since vinegar and table salt can both be used as organic herbicides, keep them away from your compost.
While “real” charcoal is used by gardeners, most charcoal briquettes sold for grills are treated with petroleum-based products—a definite “no-no” for the heap.
When in doubt, keep it out of your compost!
Don’t compost heaps smell?
If properly set up, not any more than the woods do in autumn or spring. An unpleasant odor is a sign that the pile is not balanced; either there are too many greens or not enough air. Adding some browns and turning the pile should bring the pile back into balance.
Won’t it attract rodents and wild animals?
Again, not if properly set up and maintained. After each application of greens, cover your pile with browns (this will help to absorb and mask any odors). If you are very concerned, you can cover your bin with a tarp or purchase a bin that has a locking cover. And remember, meats or fats in the compost pile takes longer to decompose and is quite attractive to animals. Avoid putting these in your compost pile.
What Fancy Equipment Do I Need to Compost?
In truth, all you need is organic waste (meaning plant or animal matter). Boxes or bins help to keep things tidy, but you can simply pile everything into a heap. Some people use discarded wooden shipping palates to frame a 4’ x 4’ bin (this size is considered optimum for composting). You may see compost “drums” sold, which hasten the process by making it easy to turn the pile frequently. Some people don’t even go to that much bother; they simply bury their eggshells, coffee grounds, peels, and what-have-you in the ground near plants that need a nutritional boost.
To best understand what works for you, it helps to understand the process.
So how does it work?
Nature composts constantly in a cycle of renewal. The fallen leaves of autumn decay on the forest floor, which, with a bit of help from microbes, earthworms, and time, will provide nutrients to the very trees from which those leaves fell.
Gardeners work to replicate this natural process by providing the same things nature does. A compost pile must have the aforementioned greens, browns, a little moisture, and oxygen. Most successful composters “build” their piles somewhat like a cook would “build” a lasagna: for every layer of greens, add two layers of browns. This again replicates the “layering” caused by the seasonal changes in nature: autumn leaves, winter snows, spring bulbs and greens and so on.
A successful compost heap should have a moisture level reminiscent of a wrung-out sponge: too dry, and nothing will break down; too wet, and the pile will give off odors.
Oxygen is important, since the microbes that break down the organic matter need to breathe! Don’t cram or push down the material in your pile. You may even want to aerate the pile occasionally (every week or so). This can be as simple as poking holes in the pile with a stick or as involved as using a pitchfork to thoroughly mix the whole heap. To return to the cooking metaphor, think of tossing a salad.
What’s this?
• There’s steam rising out of my compost heap! Is it on fire?
Congratulations! You have happy microbes that are busy breaking down your leftovers. Compost heaps can reach upwards of 1600F. When things cool down a bit, turn the pile again, and re-wet it if it appears to be drying out. Your pile may heat up again.
• My pile is covered with white stringy things that aren’t moving!
Another good sign! This fungus, mycorrhizae, is reported to both help in decomposition and boost the immune systems of plants.
• I have white stringy things that are moving!
Not the best sign, but all is not lost. You may be hosting some grubs or worse—maggots. Instead of taking this as a tragedy, recognize that it is a sign that you need to add some browns to dry out your pile and you should turn things a bit to get air.
• It’s full of worms!
If you have earthworms (brown or red “moist” looking creatures) and not grubs or maggots, you have done well in mimicking nature’s process. Earthworms aerate the pile and, by dining on your leftovers, aid in breaking down organic matter.
• It shrunk!
Yup, that will—and should—happen. Expect your finished compost to take up about half of the volume of the original contents of the pile.
How do I know when it’s done?
Compost actually has stages (or, as some diehard fans might say, vintages) and can be used at different stages of maturity. When the pile is approximately half of its original size and the contents are generally unrecognizable from their original state, you can use the compost to top-dress or mulch most plantings. If you wish to use the compost as a potting medium, you may wish to wait until you have so-called “black gold,” fine, crumbly, odorless or sweet-smelling finished compost. You may use a sieve or screen to separate any twigs or stones from the finished compost.
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