Compost In Your Backyard
Composting outdoors is easy. All you need is a bin, organic waste, air, moisture, and a shovel or other turning tool! Mix and layer brown and green materials, keep it damp and aerated. Buy a plastic backyard bin at Pemberton Farms (2225 Mass Ave), Tags Hardware (29 White St), or the Boston Building Resources (100 Terrace St). Pemberton Farms will sell the same compost bin that Cambridge DPW offered in the past, for $60.
For faster decomposition chop materials into small pieces, aerate the pile frequently, add more greens – specifically fresh grass clippings. If you mix the pile once a week, the compost should be ready in 1-2 months. If you don’t turn it, it will take 6-12 months. A lack of oxygen will slow down the composting process and cause odors, so make sure to turn, fluff and poke your pile. In terms of moisture, the pile should be as damp as a wrung-out sponge, but not dripping wet. Leaves should be damp when added. Keep a cover on to retain moisture in hot weather.
What to Compost?
Browns (carbon sources)
- Pine Needles
- Wood Chips
- Straw & Cornstalks
- Shredded Newspaper
- Crumpled Cardboard and Paper Bags
- Paper Towels, Napkins, & Tissues
Greens (nitrogen sources)
- Grass Clippings
- Weeds & Garden Trimmings
- Dead House Plants & Potting Mix
- Vegetable & Fruit Scraps (Mold is OK. Rot is part of composting.)
- Bread & Grains
- Tea Bags, Coffee Grounds & Filters (Moldy or lightly soggy food scraps are fine)
- Hair & Lint
- Manure from Farm Animals
- Alfalfa Hay/Meal & Blood Meal
What NOT to Compost
- No Branches Over ½ “ Diameter
- No Sawdust from plywood
- No Treated/Painted Wood
- No Coated Photo & Copy Paper
- No Colored Paper & Waxed Cardboard
- No Meat, Fish, Poultry or Dairy Products
- No Oily Food
- No Pesticide-Treated Grass Clippings
- No Diseased Plants
- No Invasive Weeds & Weed Seed Heads (set out for Curbside Yard Waste Collection)
- No Pet Waste & Litter
How to Compost
Buy a composter from the City. Or, to make a bin, drill holes in a trashcan. All compost bins must have a secure cover, floor and openings no wider than ½”.
Set up the bin in a convenient location close to the house, preferably in a sunny spot with good drainage.
- If you can, place in a sunny spot. This will warm up the bin and “cook” the compost quicker than in the shade.
- The spot should have good drainage and if possible, close to the house to make it easy to get to in the winter.
Start the pile with a layer of coarse material and always bury "greens", or cover with "browns".
- Remember 3 parts "browns" to 1 part "greens". Alternate layers of "browns" and "greens" . You can put shovel soil on top of each layer. Place a 4-6" layer of small branches or hay inside the bin to allow for air movement and drainage.
- Fill bin at least half full with dried leaves or other "browns".
- Store kitchen scraps bound for the compost bin in a tight-lid container.
- Create a hole in the center and bury food waste and other "greens".
- Bury food scraps in pile’s center to eliminate odors and avoid attracting rodents.
- DO NOT INCLUDE meat, dairy, fish or any foods cooked in oil or butter.
- Shred or chop leaves to shorten the composting time.
Ensure your compost bin is damp and well-aerated.
- Use a pitchfork, shovel or turning tool to fluff and aerate the pile each time you add material.
- Use a screen to harvest the humus (a milk crate with openings of 1” or less works quite well).
- In the fall, a leaf shredder is handy and best shared among neighbors.
- Dry compost? Add water, turn pile, add greens and chop/remove large wood materials. A damp pile ensures decomposition.
- A complete turning of the pile - so the top becomes the bottom - in spring and fall should result in finished compost within a year. More frequent turning will shorten the composting time.
What are some best practices to keep my compost bin and garden free from rodents?
- Pick up fallen fruit or vegetables from your garden.
- Never add meat, dairy or cooked oily foods to your composter. Rinse out eggshells.
- Bury food in your compost bin or cover it up every time with “browns” such as leaves, crumbled newspaper or torn cardboard.
- Keep your composter moist and active, with the lid closed securely.
- Keep your composter at least 1 foot from any wall or fence.
- Try to move your composter to a more convenient location. Rodents avoid areas that are regularly used or passed by.
- Clear weeds or tall grass around your bin.
- Put bird food in feeders only and don’t overfeed. Store seeds in containers with tight lids.
How can I use the finished compost?
Composted materials are ready to use when it looks like rich, brown soil. Try to harvest your compost in the late summer or fall to make room for new leaves.
- Potting Soil: To make potting soil, mix equal parts of compost, sand and loam. Remove large particles and return to pile.
- Soil Amendment: Apply ½-3” of finished compost and mix with the top 4” of soil one month before planting.
- Lawn Top-Dressing: Spread it ¼” deep over the entire lawn to reseed and rejuvenate turf.
- Moisture-Holding Mulch: Apply 2-3” around garden plants, shrubs and trees.
- Compost Tea: Steep a shovel full of compost in a 5-gallon bucket for a few days to pour on plants. Use more water or less compost if watering seedlings.
Other Rodent-Resistant Compost Bins
How can we help you? I'd like...
Dept of Public Works
147 Hampshire St
Hours of Service
Recycling Center Hours
Tuesday & Thursday: 4:00pm-7:30pm
Ms. Randi Mail
Director of Recycling
Cambridge Mobile Apps
Keeping you connected wherever you are. Learn more about Mobile Cambridge