Which compost bin do master gardeners prefer?

by / Featured, Gardening No Comments

Post By RelatedRelated Post

Simply placing the material back into the bin is all the turning necessary.

Simply placing the material back into the bin is all the turning necessary.

Many home gardeners recognize the value of composting, but the thought of wrangling big, unwieldy bins is overwhelming. So many never get started.

The master gardeners at the Sacramento County Cooperative Extension hope to make the task easier for you.

To test which of the many styles of compost bins are most effective, master gardeners set up a variety of bins and used them this year to see which ones produce the best compost and are easy to handle. The answer is surprising.

Large, expensive bins on stands, even if they had cranks and other mechanisms to allow for turning, proved to be too heavy to manipulate once filled. Virtually all of the plastic bins had insufficient air flow, and emptying the compost was a bit difficult.

On the other end of the spectrum, large wood frames with chicken wire had too much air flow and kept the compost too dry. They also took up quite a bit of space and were difficult to move.

The perfect compost bin

The master gardeners’ favorite bin ended up to be a combination of the two extremes. As a bonus, they were also the cheapest and simplest to use.

A geobin is a 3-foot-high cylinder made of thick black plastic with holes. They cost from $30 to $45 and are available at many garden centers, or can be purchased online. (See this geobin at the Little Green Wheelbarrow store).

Master gardeners' favorite bin is easily removed.

Master gardeners’ favorite bin is easily removed.

The advantage of this style of bin is that it is easy to lift off the compost pile and set down in a new spot to be refilled. Or if necessary, it is easily taken apart and reassembled. Here’s how it works:

1. Fasten the edges together to create a cylinder (many new styles have easy-release hooks).

2. Set the bin in a convenient area in your garden where you will be able to maneuver as you add material. Leave a space next to it where the bin can be moved when it’s time to turn the compost material.

3. Build your compost pile with layers of what the master gardeners call “brown” material and “green” material. “Browns” are dry, woody material like fallen leaves, wood shavings, straw, coffee filters or eggshells. “Greens” are nitrogen-rich materials like grass clippings, green leaves, young weeds, fruit and vegetable waste. Layer browns and greens to build up your first pile, then store new material elsewhere. Do not add it to the pile once it begins composting.

compost thermometer

Bacteria and fungi thrive at temperatures between 122-131 degrees F.

3. Master Gardener Rosella Shapiro recommends using a compost thermometer to test the temperature of the pile; it will get warmer as the bacteria and fungi do their job. Take the temperature when you first establish the pile, and check often. (Shapiro just leaves the temperature gauge in the pile and looks at it occasionally.) Bacteria will thrive at temperatures of 122-131 degrees F. Don’t let the pile get above 160 degrees F, though, or the bacteria will die and the compost process will stop.

4. If the pile is getting too hot, or if the temperature isn’t rising any more, it’s time to turn the pile. Turning aerates the pile and redistributes the fungi and bacteria. Lift the plastic cylinder off the pile and set in its new location. Use a pitchfork with closely spaced tines to move the material into the bin again.

Add water to each layer of compost material.

Add water to each layer of compost material.

5. Water between layers; the pile should be kept as wet as a damp sponge. If you’re not getting rain, water the pile occasionally. “If it’s too dry the bacteria and fungi can’t live and everything stops,” Shapiro says.

6. If pests are a problem, cover the bin. Otherwise, just leave it open to the air.

For more complete instructions, see this detailed guide to composting from the University of California Cooperative Extension, which offers many fine handouts on a variety of gardening topics.

Some tips on working with compost

Keep in mind that composting is the process of breaking down organic matter into a soil amendment. This occurs by the action of bacteria and fungi, and you don’t want that bacteria in your lungs or on your hands. So always wear gloves when working with composting material. Keep piles wet so you don’t breathe bacteria-laden dust.

Turn the pile about once a week, and with this mixed compost technique you should have rich brown compost after three to eight months. Scatter it throughout your garden and wish your plants a bon appétit!

Kristi Garrett

Kristi Garrett is the Publisher, Editor and Chief Veggie Enthusiast of Little Green Wheelbarrow. After 16 years in journalism and corporate communications, she figures it's time to get some dirt under her nails.