Is a compost starter necessary?

You do not need to spend $10 to $20 to get your pile started. There are plenty of microbes available for free. In fact, there are microbes in just about everything we throw on our compost pile—think of all those uneaten tomatoes disintegrating on the kitchen counter. If you are starting a brand-new pile, a shovelful of leaf mold or other naturally composted matter from the woods is a great source of the bacteria and fungi needed to get things going. In an older pile, the compost and soil are chock-full of all the fungi and bacteria you need to break down organic matter; scoop from the bottom and sprinkle on top as you turn.

What’s all the fuss about carbon and nitrogen?

Aerobic bacteria, the workhorses of decomposition, need carbon and nitrogen to do their job. Experts recommend a carbon-to-nitrogen ratio of 25:1 to 30:1 for the fastest breakdown of materials; however, the numbers just need to be in the ballpark. The general rule is to have enough greens for your browns. Typically, green, fresh, and colorful debris provides a good source of nitrogen. Coffee grounds are an exception; they are full of nitrogen. Other browns and beiges—chopped-up autumn leaves and twigs, wood chips, and straw—provide carbon. Although a pile of autumn leaves will eventually break down on its own, adding some high-nitrogen lawn clippings, vegetable scraps, and coffee grounds will speed things along. If your pile is just sitting there as recognizable chunks, you may need more nitrogen-heavy additions. If it’s working up a big stink, back off on the nitrogen and add more carbon-rich items, such as leaves and straw. If you’re adding both kitchen waste, which is typically high in nitrogen, and yard waste, which is generally high in carbon, then your pile should be in good shape as long as you mix the waste before or after adding it to the pile. And contrary to some beliefs, there is no need to add lime to compost. Many microbes are most active at a moderately low pH.

Can I compost weeds?

Yes. But what about the seeds, you ask? The key is to pull weeds before they set seed. There’s hope, though, if you miss that often narrow window of opportunity (as many of us do). Once your compost pile gets rolling and hits 130°F, that’s enough to kill the seeds of many species. The Weed Science Society of America, however, recommends up to 30 days at 145°F or more to disarm some tougher seeds, such as lamb’s-quarters (Chenopodium album), field bindweed (Convolvulus arvensis), and broadleaf dock (Rumex obtusifolius). Remember that even if your pile doesn’t get that hot, weed seeds will probably germinate and die as soon as you turn the pile and bury them. The same is true for spores of fungal pathogens. And the bigger the pile, the hotter the middle will be.

Is it necessary to turn my compost pile all the time?

If you are creating compost to use in the garden, more frequent turning accelerates the decomposition process. If waste reduction is your goal, turn the pile every once in a while. For those who are not interested in expending much effort at all, just keep piling it on. If you have a reasonable carbon to nitrogen mix to start with, decay happens—it just takes longer in an unturned pile.

Is it all right to compost meat, bones, and fat?

No doubt we have all heard the cardinal rule that we cannot toss animal parts into a compost pile. This is not necessarily true. Poultry farmers have been composting chicken carcasses for decades. Dairy and hog farms are giving it a try, and it may now be more feasible for the backyard gardener than previously thought. Recent research by Lynne Carpenter-Boggs of Washington State University on mortality composting (composting animal parts) demonstrates that potentially pathogenic bacteria and viruses from animal scraps are killed after three days of compost temperatures of at least 131°F. To avoid odors from animal products, put the waste in the middle of the pile—where the heat is—with plenty of carbon-heavy materials piled on top. If your concern is that wildlife (or your own pets) may be drawn to the pile, then using animal scraps may be more trouble than it’s worth.

Do I really have to take my compost’s temperature?