Composting, Vermicomposting and Organics



Composting is a natural process that recycles leaves, grass clippings, and small twigs into rich organic matter. Composting returns organic matter to the earth for reuse; and compost is one of nature’s best mulches. It can benefit even the smallest yard or garden and can be used around trees, shrubs, and in planter boxes.

Because it is easily turned into a resource, yard waste is banned from landfill disposal and, therefore, cannot be disposed of with regular trash. Residents have three options to manage their yard waste:

  • Subscribe for yard waste collection through their trash hauler or municipality;
  • Take yard waste directly to a commercial composting facility where it is composted (fees vary by facility);
  • Compost the yard waste in their own backyard.
How Can I Compost?

The breaking down of organic matter is a cycle that occurs in nature without any human intervention. When you compost in your backyard, the goal is to provide a satisfactory environment for nature’s decomposers (bacteria, fungi, and invertebrates) to do their work. Composting can be done actively, with frequent turning, or passively, with little to no turning. Active piles break down faster, but the basics for both methods are the same.


Choose a level area in your backyard with good water drainage – partially shaded is best. The availability of water is a plus. Compost bins are not necessary to make good compost, but they help. You can simply rake your compost ingredients into a mound. The key is to keep the pile large enough to hold heat (at least 3’ x 3’ x 3’) but small enough for air to reach the center (no more than 5’ x 5’, but it can be any length).

Composting Bin

For best results, compost should contain alternating layers of “green” and “brown” plant matter. Brown materials provide carbon to the pile and consist of dried leaves, small twigs, wood chips, and straw. Green materials provide nitrogen and include grass, flowers and stems, and fresh plant trimmings.

When composting, do NOT use:

  • Meat, grease, or dairy products;
  • Weeds that have gone to seed;
  • Diseased or infected plants;
  • Animal waste.

Compost piles need watering or they will become dormant; however, too much water can cause odors. In general, keep the pile as moist as a damp sponge. It is best to water the materials as you add them.


If choosing to maintain an active compost pile, the most effective way to determine when to turn the pile is by monitoring pile temperature. The pile should be turned whenever there is a substantial decrease in heat. A simpler method is to turn the pile five to ten days after new material is added (a pile will benefit by turning, but it is not essential). You can also use a broomstick or a pitchfork to poke holes in the pile to allow air in.

Finished Compost
Finished Compost

The compost is “finished” when it is dark and crumbly and the materials are no longer recognizable. The compost can now be used as a soil amendment, mulch, or as a seed starting mix.


The Saint Louis County Waste Code requires backyard compost piles to comply with the following:

  • It must be managed to prevent the harborage of rodents and pests.
  • It must be maintained to prevent odors.
  • Meat scraps, bones, fatty foods, and pet feces are not permitted in a residential compost pile.
  • It must be located at least three (3) feet behind the front of the main residential structure.
  • It must be located to prevent leachate (the water that has come in contact with the compost) from flowing onto adjacent property or into natural or human-made storm channels.
  • Compost piles abutting adjacent properties must not be visible from adjacent property (shielded from view by shrubbery or an enclosure).
  • Composting enclosures must comply with all local zoning regulations.

Composting is easy, but there are some common problems that can be avoided. The following table is a simple guide to keep your pile “breaking it down”!

Composting Trouble-Shooting Guide
Symptom Problem Solution
The compost has a bad odor. There is not enough air. Turn it.
The center of the pile is dry. There is not enough water. Moisten the pile while turning it.
Pile is damp and warm in the middle but nowhere else. The pile is too small. Collect more material and mix the old into a new pile.
The pile is damp and sweet smelling but it won’t heat up. The pile lacks nitrogen. Add green material.

To learn more about composting, visit the Missouri Department of Natural Resources’ website: Homeowners' Composting Guide, How to Manage Yard Waste

Grass Cycling - "Mulch" Easier than Bagging

A healthy lawn and grass cycling go hand in hand! Do your back and your lawn a favor and kick the bagging habit! (Some people may refer to it as “grass recycling”, but the proper term is “grass cycling”.)

Grass clippings are a valuable source of nitrogen-rich organic matter. When mowing, remove no more than one-third of the total plant height so that the clippings are small enough to sift back down into the turf and break down quickly, thus returning valuable nutrients back to the soil. Using a mulching lawn mower or simply converting your existing mower with a mulching attachment is an easy way to practice grass cycling.

Mulching your grass clippings does not cause thatch! Thatch is a layer of living and dead organic matter that occurs between the green matter and the soil surface. It is actually the tough fibrous part of the grass stem (which takes much longer to decompose) that contributes to thatch buildup. However, clippings are very high in water content and break down rapidly when returned to the lawn after mowing (assuming the lawn is mowed regularly and that no more than one-third of the leaf blade is being removed during mowing).

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Vermicomposting: Amazing, Grazing Worms

Think you don’t have room to compost? Think again! You can still turn your organic garbage into an amazing nutrient-rich fertilizer, even if you do not have a backyard. All you need is a little help from worms. Worm composting – or vermicomposting – is a way for you to bring organic waste recycling indoors. It requires little space and maintenance.

Vermicomposting takes advantage of natural decomposition processes. Worms and other organisms get their energy from carbon in decaying plant waste and protein from the nitrogen found in fruit and vegetable waste. The decomposers convert your leftover food and plant waste into a useful waste material called castings. Castings are rich in nitrogen, phosphorus, magnesium, and potassium so they benefit soil health.

Starting Your Worm Bin

There are four things needed for a successful vermicomposting system: a worm bin, bedding, worms, and food. Once you have all the necessary components, you can begin turning your garbage into natural fertilizer for your garden or house plants.

Building Your Bin

A shallow container, about 6 – 12 inches deep, made from plastic or wood is ideal. Drill quarter inch ventilation holes into the sides and bottom of your container so the worms can breathe. Slightly elevate the bin over a bin lid or cafeteria tray.

Habitat for Worms

For bedding you can use various materials such as shredded newspaper, phone book pages, cardboard, or coconut fiber. Moisten the bedding with water and fill your bin about halfway. The bedding should be as moist as a wrung out sponge. Add a handful of soil and now your bin is ready for worms. The best worms to put in your worm bin are red wigglers, known scientifically as Eisenia foetida.

What to Feed Your Worms

Worms can eat up to half of their body weight and love any combination of plant-based food wastes such as fruit and vegetable scraps, coffee grinds, tea bags, eggshells, pizza crusts, and even oatmeal. Before placing food into the bin, increase the surface area by cutting the food scraps into small pieces, and you will significantly speed decomposition. Cover the food completely with moist bedding. Avoid dairy and meat products because they generate odors and may attract unwanted pests.

Keep an Eye on Your Worms

Maintaining a worm bin is simple but here are a couple of tips to keep your worms happy and healthy.

  1. Rotate placement of food waste.
  2. Check the moisture content. Add water if the bedding is too dry or add dry bedding and fluff, if it is too wet.
  3. If you get more fruit flies than desired, consider reducing the amount of fruit in your bin. Another option is to place a piece of cardboard or plastic on top of your buried food waste.
  4. Add a new layer of bedding to replace the bedding already processed by the worms every so often.
Harvesting Your Vermicompost

After a few months you will see that the worms have transformed the bedding into castings also known as vermicompost. This is the time to harvest. You may leave the worms without food for about a week so they completely break down any remaining food waste. Move all the bedding material to one side of the bin. Add fresh bedding and food to the other side. After several weeks, all the worms will have migrated to the fresh side allowing you to collect the finished vermicompost.

Another way to harvest is to place all the bedding material from the bin onto a large plastic covering. Divide the material into small piles. Shine a light on a pile and as the worms burrow down, remove the top portion of castings. The worms will continue to move deeper until most of the vermicompost has been harvested. Place the remaining worms and material into fresh bedding.

How to Use Your Vermicompost

Mix the finished vermicompost with soil in a garden or house plants. Add castings to seedlings and transplants. Using worm castings as a soil amendment will increase the water and nutrient holding capacity of the soil or you can simply sprinkle it on your lawn.

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Diversion of organic waste from landfill disposal is a growing trend nationwide. Saint Louis County is currently increasing efforts toward this goal through encouragement of composting programs.

What Are Organics?

Organic wastes are materials that can be broken down into nutrient-rich humus through the natural compost process. The Saint Louis County Waste Code defines organics as any carbon-hydrogen based material by-product from food production, clothing, agricultural and horticultural operations, landscape maintenance, forestry and timber industry, animal and human waste, bio-solids or other materials originally from plants or animals.

One of the main constituents of the organic waste stream is food waste. The EPA estimates that 100 billion pounds of food waste – about 3,000 pounds per second – is generated each year in the U.S. Although the waste diversion rate for many materials has substantially increased since the 1970’s through implementation of single stream recycling programs, the generation of food waste has increased by approximately 50% during the same time period.

Another major constituent of the organic waste stream is yard waste. Yard waste is comprised of grass clippings and trimmings from bushes, trees, and other yard vegetation. Disposal of yard waste in landfills is generally not necessary (and in most cases banned), as these materials are easily composted into a resource that enriches soils and gardens. Since the yard waste ban went into effect in the early 90’s, backyard composting has become quite popular and commercial composting is a growing industry.

Management of Organics

The best way to manage organic waste is to reduce the amount generated (Source Reduction). The EPA suggests following the hierarchy in the adjacent graphic to manage food wastes. Reducing, recovering, and recycling organic waste diverts organic materials from landfills and incinerators, reducing greenhouse gas emissions from landfills and waste combustion. The use of recycled organic waste (compost) has many environmental benefits such as: improving soil health and structure; increasing drought resistance; and reducing the need for supplemental water, fertilizers, and pesticides.

In Saint Louis, the infrastructure is not quite there yet for widespread organics collection. You can express your interest in adding organics to yard waste collection programs by contacting your local officials. In the interim, try composting or vermicomposting.

Organics Pyramid