Composting and Recycling

Compost is the single most important supplement you can give your garden soil!

Composting is a simple way to add nutrient-rich humus which fuels plant growth and restores vitality to depleted soil. It's also free, easy to make and good for the environment. Composting keeps waste out of landfills, improves soil drainage allowing rain water to be absorb rather than run off and cause erosion.

compost tumbler being emptied into a wheel barrow

Composting Benefits

  • Soil Conditioner

    With compost, you are creating rich humus for lawn and garden. This adds nutrients to your plants and helps retain moisture in the soil.

  • Recycles Kitchen & Yard Waste

    Composting can divert as much as 30% of household waste away from the garbage can.

  • Introduces Beneficial Organisms to the Soil

    Microscopic organisms in compost help aerate the soil, break down organic material for plant use and ward off plant disease.

  • Good for the Environment

    Composting offers a natural alternative to chemical fertilizers.

  • Reduces Landfill Waste

    Most landfills in North America are quickly filling up; many have already closed down. One-third of landfill waste is made up of compostable materials.

What to Compost

Material Carbon/​Nitrogen Info
Table scraps Nitrogen Add with dry carbon items
Fruit & vegetable scraps Nitrogen Add with dry carbon items
Eggshells Neutral Best when crushed
Leaves Carbon Leaves break down faster when shredded
Grass clippings Nitrogen Add in thin layers so they don't mat into clumps
Garden plants -- Use disease-free plants only
Lawn & garden weeds Nitrogen Only use weeds which have not gone to seed
Shrub prunings Carbon Woody prunings are slow to break down
Straw or hay Carbon Straw is best; hay (with seeds) is less ideal
Green comfrey leaves Nitrogen Excellent compost 'activator'
Pine needles Carbon Acidic; use in moderate amounts
Flowers, cuttings Nitrogen Chop up any long woody stems
Seaweed and kelp Nitrogen Apply in thin layers; good source for trace minerals
Wood ash Carbon Only use ash from clean materials; sprinkle lightly
Chicken manure Nitrogen Excellent compost 'activator'
Coffee grounds Nitrogen Filters may also be included
Tea leaves Nitrogen Loose or in bags
Newspaper Carbon Avoid using glossy paper and colored inks
Shredded paper Carbon Avoid using glossy paper and colored inks
Cardboard Carbon Shred material to avoid matting
Corn cobs, stalks Carbon Slow to decompose; best if chopped up
Dryer lint Carbon Best if from natural fibers
Sawdust pellets Carbon High carbon levels; add in layers to avoid clumping
Wood chips/​pellets Carbon High carbon levels; use sparingly

You can also add garden soil to your compost. A layer of soil will help to mask any odors, and micro-organisms in the soil will accelerate the composting process.

Do not compost meat, bones or fish scraps (they will attract pests), perennial weeds (they can be spread with the compost) or diseased plants. Do not include pet manures in compost that will be used on food crops. Banana peels, peach peels and orange rinds may contain pesticide residue, and should be kept out of the compost. Black walnut leaves should not be composted. Sawdust may be added to the compost, but should be mixed or scattered thinly to avoid clumping. Be sure sawdust is clean, with no machine oil or chain oil residues from cutting equipment.

For kitchen wastes, keep a container with a lid and a handle under the sink. Consider using a stainless steel compost pail with air filter, or the ceramic model. If you don't mind occasional smells, use an old ice-cream pail. Chop up any large chunks before you toss them in. When the container is full, take it out to your composter and toss in the contents.

With yard and garden wastes, different composting materials will decompose at different rates but they will all break down eventually. If you want to speed up the composting process, chop the larger material into smaller pieces. Leaves and grass clippings are also excellent for compost, but should be sprinkled into the bin with other materials, or dug in to the center of the ple and mixed. Avoid putting them on in thin layers - they will mat together and reduce aeration, which slows the composting process.

How to Compost

  1. Start your compost pile on bare earth. This allows worms and other beneficial organisms to aerate the compost and be transported to your garden beds.
  2. Lay twigs or straw first, a few inches deep. This aids drainage and helps aerate the pile.
  3. Add compost materials in layers, alternating moist and dry. Moist ingredients are food scraps, tea bags, seaweed, etc. Dry materials are straw, leaves, sawdust pellets and wood ashes. If you have wood ashes, sprinkle in thin layers, or they will clump together and be slow to break down.
  4. Add manure, green manure ( clover, buckwheat, wheatgrass, grass clippings) or any nitrogen source. This activates the compost pile and speeds the process along.
  5. Keep compost moist. Water occasionally, or let rain do the job.
  6. Cover with anything you have - wood, plastic sheeting, carpet scraps. Covering helps retain moisture and heat, two essentials for compost. Covering also prevents the compost from being over-watered by rain. The compost should be moist, but not soaked and sodden.
  7. Turn.Every few weeks give the pile a quick turn with a pitchfork or shovel. This aerates the pile. Oxygen is required for the process to work, and turning "adds" oxygen. You can skip this step if you have a ready supply of coarse material, like straw.

Once your compost pile is established, add new materials by mixing them in, rather than by adding them in layers. Mixing, or turning, the compost pile is key to aerating the composting materials and speeding the process to completion.

Note: If you want to buy a composter, rather than build your own compost pile, you may consider a buying a rotating compost tumbler which makes it easy to mix the compost regularly.

Carbon/​Nitrogen Ratio

Carbon to nitrogen compost ratio is 30 parts carbon to 1 part nitrogen

All compostable materials are either carbon or nitrogen-based, to varying degrees. The secret to a healthy compost pile is to maintain a working balance between these two elements.


Carbon-rich matter (like branches, stems, dried leaves, peels, bits of wood, bark dust or sawdust pellets, shredded brown paper bags, corn stalks, coffee filters, conifer needles, egg shells, straw, peat moss, wood ash) gives compost its light, fluffy body.


Nitrogen or protein-rich matter (manures, food scraps, green lawn clippings and green leaves) provides raw materials for making enzymes.

A healthy compost pile should have much more carbon than nitrogen. A simple rule of thumb is to use one-third green and two-thirds brown materials. The bulkiness of the brown materials allows oxygen to penetrate and nourish the organisms that reside there. Too much nitrogen makes for a dense, smelly, slowly decomposing anaerobic mass. Good composting hygiene means covering fresh nitrogen-rich material, which can release odors if exposed to open air, with carbon-rich material, which often exudes a fresh, wonderful smell. If in doubt, add more carbon!

Simplest Composting Methods

"No-Turn" Composting

The biggest chore with composting is turning the pile from time to time. However, with 'no-turn composting', your compost can be aerated without turning.

The secret is to thoroughly mix in enough coarse material, like straw, when building the pile. The compost will develop as fast as if it were turned regularly, and studies show that the nitrogen level may be even higher than with turned compost. With 'no-turn' composting, add new materials to the top of the pile, and harvest fresh compost from the bottom of the bin.

fallen maple leaves

Composting Leaves

If you have too many leaves to incorporate into the compost bin, you can simply compost the pile of leaves by itself. Locate the pile where drainage is adequate; a shaded area will help keep the pile from drying out.

The leaf pile should be at least 4' in diameter and 3' in height. Include a layer of dirt between each foot of leaves. The pile should be damp enough that when a sample taken from the interior is squeezed by hand, a few drops of moisture will appear. The pile should not be packed too tightly.

The pile will compost in 4 - 6 months, with the material being dark and crumbly. Leaf compost is best used as an organic soil amendment and conditioner; it is not normally used as a fertilizer because it is low in nutrients.

Leaf-Mould Tea

You can also use leaves to make a nutritious "tea" for your plants. Simply wrap a small pile of leaves in burlap and immerse in a garbage can or large bucket of water. Leave for three days, then remove the "tea bag" and dump contents into the compost. Scoop out the enriched water with a smaller bucket and use to water your plants and shrubs.

Enclosed Compost Bins

For small-scale outdoor composting, enclosed bins are the most practical. The least expensive method is to build one yourself from a heavy-duty garbage can. Simply drill 1.5-cm aeration holes in rows at roughly 15-cm intervals around the can. Fill the can with a mixture of high-carbon and high-nitrogen materials. Stir the contents occasionally to avoid anaerobic pockets and to speed up the composting process. If the lid is secure, the bin can be laid on its side and rolled; a length of 2" cedar ( use a 2x2 or a 2x4) can be bolted to the inside, running top to bottom, to help flip the material. Without this, the contents tend to stay in place while the bin is rolled.

Another option is a compost bin, sometimes called a 'compost digester'. Compost bins are enclosed on the sides and top, and open on the bottom so they sit directly on the ground. These are common composting units for homes in residential areas where bins tend to be smaller, yet enclosed enough to discourage pests. These bins are inexpensive, but it is difficult to turn the compost, so it can take several months to produce compost. These bins are thin-walled plastic, and may chip along the edges, especially during a freeze.

The most efficient enclosed bin method is the compost tumbler. It's possible to maintain relatively high temperatures in drum/tumbler systems, both because the container acts as insulation and because the turning keeps the microbes aerated and active. An interior "paddle" aids aeration and prevents clumping of the composting materials. This greatly speeds up the composting process.

An enclosed 'tumbler' system offer the following benefits:

  • Speeds up the composting process
  • Can compost year-round, due to higher internal temperature
  • Cannot be accessed by rodents, raccoons, dogs or other critters
  • Keeps compost neatly enclosed and odor-free, well-suited for residential areas

Tips for Successful Composting

Activate Your Compost

'Activators' can be added to your compost to help kick-start the process and speed up composting. Common compost activator materials are: comfrey leaves, grass clippings, young weeds, well-rotted chicken manure.

Flying Insects

Small fruit flies, especially, are naturally attracted to the compost pile. They can be discouraged by simply covering any exposed fruit or vegetable matter. Keep a small pile of grass clippings next to your compost bin, and when you add new kitchen waste to the pile, cover it with one or two inches of clippings. Adding lime or calcium will also discourage flies.

Unpleasant Odors

This can be a concern in urban and suburban areas with small lots and neighbors living close by. Odors can be reduced, or eliminated, by following two practices: first, remember to not put bones or meat scraps into the compost; second, cover new additions to the compost pile with dry grass clippings or similar mulch. Adding lime or calcium will also neutralize odors. If the compost smells like ammonia, add carbon-rich elements such as straw, peat moss or dried leaves.

Steaming Compost Pile

No problem. A hot, steamy pile means that you have a large community of microscopic critters working away at making compost.

Soggy Compost Pile

This is a common problem especially in winter when carbon-based materials are in short supply. You can restore your compost to a healthy nitrogen-carbon balance.

To learn how restore your compost pile, read the article How to Fix a Soggy Compost Pile.

Matted Leaves, Grass Clippings Clumping Together

This is a common problem with materials thrown into the composter. The wet materials stick together and slow the aeration process. There are two simple solutions: either set these materials to the side of the composter and add them gradually with other ingredients, or break them apart with a pitchfork. Grass clippings and leaves should be mixed with rest of the composting materials for best results.

Problems With Raccoons

If there's a population of raccoons in your area, they will be naturally attracted to your compost pile. The best solution to this problem is to bar their entry to the compost. (Traps and poisons are more trouble than they're worth.) A wood or metal lid can be easily hinged to the bin described above.

A Movable Feast

The soil beneath a compost bin becomes enriched as nutrients filter down with successive waterings. You can place your bin on a plot of earth which you plan to use for a future vegetable or flower bed, or fruit tree. Each year, you can move the bin to a different area; you'll get a double benefit - the compost from the bin, and a bed of nutrient-rich soil ready for new plantings.

Additive Only

Compost should be used as a soil additive, and not exclusively as the growing medium. Compost is a source of rich organic matter which provides nutrients for growing plants, but should be thought of as one component of a healthy garden bed. To learn more about developing healthy soil, read the article 6 Tips for Building Soil in your Raised Garden Beds and Planters.

Take Advantage of Autumn's Bounty

The biggest challenge for small-scale backyard composting is finding enough carbon-rich materials to balance the regular input of nitrogen-rich materials which come from kitchen scraps, fruit and vegetable peelings, coffee grounds, grass clippings and other fresh materials. To learn how to make the most of autumn's bounty, read Autumn Composting Tips.

Composting and weed seeds

fallen maple leaves

A liability in composting is the unexpected introduction of new weed seeds to your garden. This is caused by slow or incomplete composting which did not generate enough heat to kill any and all weed seeds. Weed seeds in compost are a nuisance because once the compost is transferred to your garden beds, the compost acts to fertilize the weeds and make them even more persistent!

With home compost bins or piles, the way to eliminate weed seeds is twofold:

  1. Make sure your compost is hot enough.
    Reach your hand into the center of the pile - it should be almost too hot for comfort. Specifically, the temperature should be 130 - 150 degrees F. It takes about 30 days at 140 degrees to kill all weed seeds.
  2. Mix your pile.
    While your compost may be hot in the center of the mass, the outside of the pile is cooler, giving seeds a chance to survive. Mixing brings cooler material to the warmer area and also increases aeration which helps attain the higher heat levels. Compost tumblers are very useful for this.

If you are buying bedding for animals, mulch or carbon-rich material to bulk up your compost pile, be aware of introducing seeds to your garden, via the compost. For example, make sure to get straw, and not hay, since straw is mostly weed-free. Ask the sales staff if there have been any complaints about seeds in these products.