Composting is the process of taking spare organic material from things like food scraps and yard waste and turning it into a useful soil amendment for your garden.
Many cities offer community composting, either via drop-off sites or home pickup. In exchange for contributing what would usually be waste from your home, you can pick up ready-to-use compost to bolster your garden. This can be a great way to give your plants a boost and get involved in environmental efforts in your community—you may even meet a Master Gardener when you visit your drop-off site!
To find a Minnesota site near you, check out the MPCA Compost Facility Locator. Check the information on the map to see which sites take yard waste and which ones take food scraps.
In some areas, community composting may not be available or convenient. Thankfully, you can still compost right at home in your own backyard or even from an apartment balcony. Many gardeners welcome this challenge, enjoying watching what would normally be garbage destined for the landfill transform into plant food.
Benefits of Composting
The organic material added by compost helps to nourish plants. Compost helps to bolster light/sandy soil, allowing it to hold more water and nutrients, and resist erosion. In overly heavy soil, it does the opposite and helps to improve drainage and aeration. Adding compost can help to prevent diseases in plants and also helps to stabilize soil pH. Composting also protects the broader environment by cutting down on the amount of material going to landfills and even curbing greenhouse gas emissions.
How to Get Started
A compost pile can be very simple, though it pays to put a little engineering into your setup. All you need to get started is a container roughly three to five feet in diameter and made of something like chicken wire, bricks, metal or rot-resistant wood like pine or cedar. Visit the University of Minnesota’s Extension Yard and Garden Page for some great ideas on how to design, place, and maintain your composting solution. Many pre-built designs can also be found at yard and garden stores, including compact composting drums, which allow for easy rotation.
You’ll want to place your compost pile in an area with at least partial sun. . The warmth from the sun will help the pile to “do its thing” and break materials down more quickly. Compost piles can naturally reach temperatures as high as 160° Fahrenheit as the microbes go to work decomposing the organic matter. Avoid placing your compost pile in an area with low sun and high winds, as this can cause the pile to become too cool and dry for it to break down in a timely manner.
If possible, start your compost pile with a layer of dead leaves and plant trimmings, then add other compostable materials on top. Add a little water to the mix, but not so much that it becomes soggy. You can then add a nitrogen source like grass clippings, vegetable peelings or wilted lettuce or a high-nitrogen lawn fertilizer free of herbicides. Finally, if you have access to any completed compost, add some to the top of the pile as this will provide a burst of microbes so the decomposition process can start right away.
Build your pile up in layers this way until it reaches a height of around five feet. You can add small amounts of new material to your pile once it’s going, but you may want to start multiple piles if you have a lot of new material to process. Adding too much fresh material to a compost pile while it’s in the process of decomposing can slow things down.
You’ll want to stir and flip your compost pile once or twice a month to encourage even and consistent decomposition. This can also help to deal with any offensive odors. Keep the pile moist but not soaked. It can take two to four months for compost to break down to the point that it’s ready for use. You’ll know your compost is ready when the pile has shrunk to about half its original height and has a dark color, consistent texture, and pleasantly earthy smell.
What to Compost
All sorts of things can be included in your compost pile. Note that the more you can break these items up before adding them to the pile, the faster they’ll decompose. Some top composting candidates include:
Dead material trimmed from plants
Dead leaves gathered in the fall
Fruit and vegetable skins and pits
Fruits and vegetables that have started to decompose
Coffee grounds, paper filters and tea leaves/bags with no plastic or metal pieces
Egg shells (but not the eggs; more on that below)
Trimmed hair, fingernails and fur from pets
Food-soiled paper products without wax coatings or attached plastic/metal (Note that unsoiled paper products that can still be recycled should go in the recycle bin.)
Smaller amounts of sawdust, wood chips and grass gathered when working on the lawn (Too much of these materials will cause your pile to become dense and less nutrient-rich.)
Hulls from nuts and seeds, except for walnuts (See below.)
What to Bring to Your Community Composting Site
A few items may not properly decompose in a backyard composting pile, as they require a higher temperature to properly break down. Others may break down fine, but can attract unwanted wildlife or create strong odors. Bring these items to your local composting site instead, but call or check online first to confirm that they are accepted there:
Certified compostable bags
Certified compostable food service items like plates and cups (Look for BPI or Cedar Grove certification labels. Note that just the word “biodegradable” doesn’t cut it!)
Scraps and bones from meat, poultry or fish
Whole eggs and dairy
Grease and oil
What NOT to Compost
Some items might seem perfect for the compost pile, but can actually carry disease, attract wildlife, produce offensive odors, or simply never break down. These items are best left in the garbage bin rather than putting them in your home compost pile or bringing to a composting site.
– Large amounts of burnt wood or ashes
– Rocks or sand
– Known noxious weeds or their seeds
– Material that has been contaminated by pests, such as jumping worms
– Material that has been treated with herbicides
– Food service products with a wax coating, attached plastic/metal, stickers, etc. (Many items like fast food wrappers have a wax coating or tinfoil lining that is not compostable.)
– Walnuts and trimmings from black walnut trees (These contain a chemical that is toxic to plants.)
– Pet or human waste
Author’s Bio:
Scott Lore is an intern with the University of Minnesota’s Extension Master Gardener program. He lives in Saint Paul with his wife Sam and their two cats, Yoshi and Toph. Scott is passionate about nature, photography, writing, music, and tabletop games. His enthusiasm for gardening stems from a long-term goal of being able to sustainably grow his own food, cultivate native species, and support pollinators to help our environment thrive.
References and Further Reading: