Composting is nature’s way of recycling. And it's easy to do right in your own backyard. Follow the simple steps below to get started.
Compost can be used as a:
- natural mulch for trees, lawn and garden plants
- soil amendment that improves the texture and moisture-holding capacity of the soil
- source of nutrients for plants
- potting medium when added to soil and sand
Backyard composting is also a great way to reduce waste.
What to Compost
Compost starts out as a combination of 25 to 50% nitrogen-rich, “green” materials and 50 to 75% carbon-rich, “brown” materials.
GREENS provide nitrogen. They are the source of protein for the microbes hard at work in the compost pile. Greens include:
• Green leaves
• Plant trimmings
• Raw fruit and vegetable scraps*
• Fresh grass clippings
BROWNS provide carbon. They are a source of energy for the microbes. Brown materials include:
• Dried grass and leaves
• Wood chips
• Small twigs and branches
• Corncobs and stalks
| *Raw fruit and vegetable scraps are the only food waste allowed for home compost bins in the City of Plymouth. Meat, dairy products or oils cause odors and attract scavengers like raccoons, rats and neighborhood pets.
Start out with a homemade or purchased composting container. It will speed composting, improve appearances and reduce the possibility of pests. A container for compost is also required by Plymouth’s city code.
Container size, type and placement
Purchase or build a container that is at least three feet by three feet in size and no larger than five feet wide by 12 feet long by five feet high.
The container must be constructed of durable materials, such as rot resistant wood, block, sturdy metal fencing or a commercially built bin designed to contain composting material.
When placing the container, look for:
• a level, well-drained area.
• accessibility from all sides.
• accessibility to a convenient source of water
Plymouth's backyard composting ordinance requires that compost bins are placed:
• in the rear yard of the property;
• at least 40 feet from the nearest neighbor’s home;
• at least six feet from any city park ,trail, property line and the resident’s house.
Preparing the materials
- Place four-inch to six-inch of base material such as dried leaves or wood chips on the ground. This will allow air circulation around base of pile. (Skip this step if using a compost mixing container).
- Alternate two to four inches of “green” organic material containing nitrogen and four to six inches of “brown” organic material containing carbon. (See above for descriptions of “green” and “brown” material.) Keep a ratio of one part green and two to three parts brown. Keep layers uncompacted so air can circulate.
- After each green and brown layer add up to one inch of an activator to introduce microorganisms into the pile. Activators such as garden soil or bone meal will provide nitrogen to encourage the reproduction of microorganisms. A pile must have microorganisms to decompose the organic waste.
- Water the pile so it’s moist, but not soaking wet. The compost should be damp enough to form a clump, but not drip when squeezed.
Tip: Save a few bags of dry leaves from fall cleanup for a source of brown material for your compost the following summer.
Maintaining a Compost Pile
Insects, bacteria, worms, centipedes, beetles and sow bugs are some of the organisms that turn yard waste and fruit and vegetable scraps into compost. They do their job best when they have adequate air and moisture, along with a mix of nitrogen and carbon materials for food.
The compost should have 50 percent moisture content and feel damp like a wrung-out sponge. Test the moisture content by squeezing a handful of the compost. It should form a clump, but not drops of water. Add moisture to the compost pile by either adding green material or sprinkling it with water.
The pile should be aerated about once a week by:
• Turning the pile, outside to inside or top to bottom;
• Stirring the pile;
• Using an air stack or aerator tool to bring air into the center of the pile; or
• Using a tumbler compost bin to rotate the pile every two to three days.
Increase the surface area to improve decomposition. Shred or cut organic material into smaller pieces.
A working backyard compost pile typically heats up to 90° to 120°. If the pile no longer heats up, it may be an indication that the compost is ready for application. If the compost is not ready, follow trouble-shooting suggestions below to improve decomposition.
With proper materials, aeration and moisture, compost should be ready in about six months. Compost is ready when it has decomposed into small, crumbly, dark brown soil-like particles. When some of the compost is ready, remove the finished compost and then start a new pile.
A properly working pile has a slight earthy smell to it or no odor at all. If that doesn’t describe your compost pile, try the following suggestions.
- To help dry an over-watered pile, add sawdust, straw or wood chips, or place wood planks underneath the pile to ensure good drainage.
- If the pile is too dry, turn it over and add greens and water.
- If the pile is damp, sweet smelling and will not heat up, it needs nitrogen. Turn the pile and add grass clippings, blood meal or urea fertilizer.
- If the pile smells like ammonia, add brown leaves, sawdust, straw or wood chips.
- If the materials do not seems to be decomposing or heating up, then add nitrogen, turn the pile and maintain 50% moisture.
- If unwanted creatures are interested in your compost, bury the food waste close to the pile’s center and avoid “compost don'ts” below.
Staw & hay
Fruit & vegetable scraps
Sawdust & wood chips
Oil or fatty foods
Weeds with seeds
Ashes or charcoal
Chemically treated yard waste
Hennepin County: How to compost
Hennepin County: Organics (food waste) composting
Recycling Association of Minnesota: Annual low-cost compost bin and rain barrel sale
Minnesota Pollution Control Agency: How to compost (PDF)
University of Minnesota Extension: Compost and mulch guide
University of Minnesota Extension: Backyard composting guide
U.S. Environmental Protection Agency: Compost information for facilities, businesses, industry
Minnesota Composting Council: Composting