Trash, Recycling & Compost

Winter Composting

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The 2020 curbside compost collection season ended on Friday, December 11, 2020. ​  It will begin again on Monday,​ April 5, 2021.

So what to do with all those plate scrapings, fruit and vegetable scraps and other materials you've been putting in the compost cart? 

We have some suggestions.

Winter means little to no leaves or yard waste, so there should be plenty of room to store plate scrapings, food scraps and other compostables in the compost cart. Here are a few ideas from Ann Arbor residents who've done it themselves:

  • Place an opened paper yard-waste bag inside the compost cart to hold the food scraps. compost bin with bag.jpg
  • Put 1-2 feet of leaves or a couple pieces of flattened cardboard (1-2 large pizza boxes are perfect) at the bottom of the compost cart before adding produce. This buffer at the bottom of the cart allows the materials to slide out more easily in the spring.
  • Add paper shreds to your compost cart to keep odors down and liquids from freezing to the cart.
  • To keep the compost cart from getting messy, wrap drippy wet items (e.g., coffee grounds, melon rinds) in 1-2 sheets of old newspaper before putting into the compost cart.
    compost bin with boxes.jpg
  • Add a layer of leaves, a few sheets of shredded newspaper, or sprinkle a shovel-full of dirt/compost if the exposed produce waste starts to get "ripe" or is looking too wet.
  • If your neighborhood has clever raccoons, secure all cart lids with a bungee cord. (Remove bungees when your carts are put at the curb in the spring pickup.) ​​

Building your own compost pile

If you would prefer to build a winter compost pile in the yard, Earth 911's Mary Mazzoni has these tips:

Prepare for the slow-down. Cold temperatures often slow or even stop decomposition, as aerobic bacteria often become more sluggish in the winter.

Even when the temperature drops, some microbes responsible for the breakdown of organic matter can remain active in the compost pile, according to the Texas AgriLi​fe Extension Service. Since the digestion process generates heat, the center of your pile may still remain warm and actively composting.

However, the outer (visible) portion of your pile will cool to outdoor temperatures. So, you may notice increased decomposition time in these areas. Don't worry about it. Once the temperature warms up, microbial activity will resume as normal as long as you maintain a healthy balance in your pile.

Build a shelter. Constructing a shelter for your compost pile is the No. 1 way to help keep it active for the entire winter season. Start by building a protective barrier around your pile with cinderblocks, bricks, sand bags or plywood, suggest the University of Illinois Extension. A barrier between your compost pile and the frigid winter air will help keep internal heat from escaping, promoting active decomposition. Not sure how to get started, a simple google search will provide you plenty of ideas to get you started.

Keep it dry. Compost piles should always be kept moist to ensure proper decomposition. But loads of winter snow and spring rain can actually drench your pile, which will force air out of pore spaces – killing your bacterial buddies. So, try to keep your pile dry and protected during the winter to ensure a healthy balance. Consider adding a roof or tarp over your compost pile and make sure it is secure.

Add the right stuff. A balanced compost pile requires carbon-rich (also called brown) materials to give bacteria energy and nitrogen-rich (also called green) materials to help them grow strong and reproduce. While equal quantities of both materials are your best bet during the spring and summer, your pile needs more "brown" matter during the winter season.

Brown materials, which include leaves, tree branches and other yard waste, give microbes the energy to continue decomposition despite chilly temperatures. So, add as much of these materials as you can when temperatures are low. In addition, try to keep green materials to less than two inches in size as frigid temperatures impede bacteria's ability to process these materials.

Dig a hole and bury it. If you're wary of loads of non-decomposed waste sitting on top of your pile until spring, take a different approach to composting until temperatures warm up. The Texas AgriLife Extension Service suggests digging a trench in the garden or flowerbed and adding organic waste (like kitchen scraps) little by little, making sure to bury the waste after each addition.

Don't have a garden at home? Just dig a one-foot hole anywhere in the yard and cover it with a board or bricks until it is full of organic waste. Once your hole is full, bury it with soil, and dig another one to keep composting all winter long.​