Compost Methods: A Quick “How to” Guide

Hot (Active) Compost is composting at high temperature to create the best environment for microbes to decompose organic material. Frequent upkeep is needed to maintain the best ratio of compostable materials and the right balance of air and water. But if managed correctly, the pile’s high temperature will destroy most weeds, plant diseases and insect larvae or eggs. Under ideal conditions, finished compost can be produced in 4 weeks but in general will take 4 to 6 months.

How to Hot Compost:

Cold (Passive) Compost is the less precise version of hot composting. The effort for upkeep is low as organic materials are added at will and aeration and moisture levels are not as important. While moderately warm due to biological activity, the compost can be susceptible to pathogens, excessive wetness, and odors. This method is ideal for those with little organic waste and not much time to spend on upkeep. The process is slow, taking up to a year to produce finished compost.

How to Cold Compost:

Vermicompost is typically done in a well-ventilated plastic or styrofoam bin. Fill half of the bin with moist, shredded newspaper to be used as worms’ bedding. Add a handful of garden soil and a pound of worms (e.g., red wigglers). Place the bin in a cool dark location with minimal temperature fluctuations; worms benefit from minimal external disturbance. Feed the worms compostable nitrogen-rich materials (e.g., fruit scraps, coffee grounds, leaves). Layer carbon-rich materials (e.g., newspaper, cardboard) on top. To prevent overfeeding, place small amounts of nitrogen-rich materials every 1-2 weeks to figure out when and how much to feed the worms. When it is time to collect worm castings (i.e., finished compost), move the castings to one side of the bin and add nitrogen-rich materials to the other side. Within a couple of weeks, the worms will migrate over to feed, and the castings can be removed. Finished compost can be made in up to 6 months. 

How to Vermicompost:

Black Soldier Fly Composting is efficient and low maintenance. Labor is only required to assemble the black soldier fly larvae (BSFL) farm. Typically, a farm consists of a plastic bin, a cardboard nest, a leachate drainage pipe, and an optional larvae ramp with an external collecting bin. Fill a third of the bin with bedding (e.g., shredded newspaper, wood chips, dirt) and add a small quantity (100+) of BSFL. Add waste materials like kitchen scraps; BSFL feed on anything that is fed to them. Keep the farm dark, moist and enclosed to encourage activity. When the BSFL pupate, they migrate away from their feeding grounds. If you choose, install a ramp into the side of the bin to collect the migrating BSFL and feed them to chickens, fish, or other animals. Tape pieces of corrugated cardboard on the sides of the bin for female adult black soldier flies to lay their eggs and repopulate the farm with BSFL. This is the cardboard nest. Install a PVC elbow joint to one end of the bin; this will drain the leachate the BSFL produce. Finished compost can be made in as little as a week. 

How to Build a BSFL Farm:

Direct Composting involves burying organic waste to make compost where it is needed. Direct composting requires no maintenance other than digging in waste material; however, large-scale composting efforts can be difficult because holes and trenches are not reusable. Finished compost can be produced in as little as 12 months if not sooner in ideal conditions.

How to Make a Compost Trench:

Sheet Compost or sheet mulch, is made up of alternating layers of cardboard/newspaper, mulch, and organic waste. Sheet composting builds fertile soils on top of existing lawns and beds. This method is used to improve soil structure, create perennial borders, convert lawns to vegetable beds, and minimize weeds. Sheet composting is a slow, cold composting process that requires advance planning to gather enough organic material and can takes 6 months to a year to make. Yet while demanding in time and material, it can be started in the fall so that decomposition occurs over the winter and new beds can often be ready for spring planting.

How to Sheet Compost

Leaf Mold produces partially decomposed leaves that have a pleasant earthy aroma, crumbly texture, and are dark brown to black in color. Unlike traditional composts, leaf mold is not nutrient-rich or used to fertilize. Leaf mold is used as a soil amendment primarily to regulate the soil climate (e.g., moisture retention, minimize runoff and temperature moderation) and improve soil tilth. Other benefits of leaf mold include moderating soil pH, promoting a crumbly soil texture, building a habitat for soil organisms like earthworms and beneficial bacteria, and weed control. Finished compost takes 6 months to a year to form.

How to Make Leaf Mold:

Bokashi is fermented organic material made from pre-processing food waste (e.g., meat, dairy, bread, cooked food) that is typically sent to landfills and generally not composted through traditional methods. The highly nutritious byproducts (liquid and fermented material) are made in a few weeks but can be too acidic for plants. It is suggested that the liquid be diluted with irrigation water for application and the solids be either buried for direct composting or added to a compost bin to complete breakdown. This second option should be avoided with meat and dairy byproducts to avoid attracting unwanted animals. Bokashi is made in a sealed container, making odors and pest attraction negligible. This makes bokashi indoor-friendly.

How to Use a Bokashi Bucket: