For the past two years, Baltimore Free Farm has taught a composting workshop at DIY Fest. The workshops have been quite successful and we hope to get even more people to start composting!
Here are some frequently asked questions that we often answer regarding compost:
What is composting?
Composting is the process of breaking down vegetable matter and other waste products into a usable, nutrient rich soil amendment.
What are the benefits of composting?
Much of the food waste and paper or cardboard trash that you would otherwise be sending to a landfill can be re-used in the form of compost. If you are a gardener, your plants will benefit from the added nutrients! If you aren’t a gardener, consider donating your finished compost to neighbors who have gardens or your local community garden. Even if you don’t have a garden or know any local gardeners, composting and simply dumping the finished compost into your yard or the woods is much better for the earth than filling landfills with food waste.
How do I compost?
In order to compost properly, you must have a balanced ratio of carbon vs. nitrogen. Nitrogen sources are things like food scraps or animal manure. Carbon sources include cardboard, shredded newspaper, dead leaves, and straw to name a few.
What can I put in my compost?
Some compostable materials include: Vegetable waste, fruit waste, Paper napkins, Hair, coffee grounds, tea bags, nail clippings, animal manures(from herbivores only!), pine needles, leaves, wood chips, banana peels, onion skins, other fruit/vegetable peels and rinds, egg shells(crush them up!), shredded paper, newspaper, moss, weeds, urine, and more.
Some things you should NOT compost include: cat or dog droppings, colored or heavily coated paper, lime, meat, fat, grease, bones, walnuts, sawdust (unless you know for sure that it did not come from chemically treated/pressure treated wood), diseased plants. Some say no orange peels, because they take so long to break down, and because over time in a closed system (where your compost is not built over bare earth) your compost will become more acidic and worms don’t like acidity.
What kind of container should I put my compost into?
If you live in an area where pests are not a concern, you may compost directly on the ground. However, if you live in a place like Baltimore City, where rats are a large problem, we suggest container composting. You can use any kind of container that will reasonably keep pests out. Large plastic bins or barrels work well; just make sure to place them off the ground (i.e. resting on top of something, like a pallet). A reasonable size for your container will depend on how much waste you need to compost at a time. In order to make sure your compost has proper drainage and air circulation, you should drill some holes into the bottom and sides of whatever container you use.
Should I turn my compost?
While your compost, if properly balanced, will eventually break down if you just let it do its thing, turning the compost helps it to break down faster. Basically, the more often you turn your compost, the faster it will be ready. A good starting point is to turn your compost once or twice a week. From there you can determine whether more or less turning is necessary for your composting needs.
What is the ratio of carbon to nitrogen that I should aim for?
Generally, the idea is that for every nitrogen source you put into your compost, you should add A LOT of carbon. The C:N ratio that some people recommend is 25:1. Another recommendation heard frequently is 2:1. So you see, it doesn’t have to be an exact science. Play with the C:N ratio and follow the recommendations below to keep your compost under control.
What if my compost is putrefying instead of composting?!
Don’t panic. The likely culprit is not enough carbon. Add more carbon!
What if my compost is too wet?
Don’t add too many liquids. Ideally your compost should be moist but not WET. If your compost is too wet, avoid adding watery fruits like watermelon, and avoid liquids for a while.
Should my compost stink?
Ideally, if your C:N ratios are correct, your compost should not smell bad. If it starts to stink something is probably wrong. Try adding more carbon.
How do I know if my compost is ready?
Finished compost should be dark brown, fluffy, and crumbly. If your compost is still hot, smells like ammonia, or there is still a lot of recognizable material, then it is not ready yet. Note that some things take longer to break down than others. If your compost is finished except for some stubborn banana peels or egg shells, simply remove the offending objects and place them into a new batch of compost. Crushing egg shells will help them to break down faster. It would be wise to let your compost sit a while longer after you think it is ready, just to be sure that the decomposition process is completely finished
How can I learn more about compost?
Google is a good starting point, and there are a lot of great books about compost out there. Here are some books that were helpful to us:
Let it Rot!: The Gardener’s Guide to Composting by Stu Campbell
Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web by Jeff Lowenfels and Wayne Lewis
The Rodale Book of Composting: Easy Methods for Every Gardener by Grace Gershuny and Debora L. Martin
ToolBox for Sustainable City Living: a Do-it-Ourselves Guide by Scott Kellogg and Stacy Pettigrew
Note: This book covers a lot of different sustainability practices and is a very useful tool for people who are interested in permaculture.