It is worth the time and money to invest in a good composting system, so before you begin, consider these factors:
Location, location, location
The best compost system for you depends on where you garden.
• If you’ve got 10 acres, you’ll need multiple bins, each being big enough for the pile to retain moisture and heat, but small enough so you can turn it with relative ease. A simple system made from wooden pallets and tucked behind the barn works. With this system, cold composting (also called passive composting) is easy. Simply pile leaves, grass clippings, and other organic yard waste in several of the bins and stockpile finished compost in the others.
• Even in a smaller garden, you may have room for three bins, tucked behind a garage or hidden in a side yard. With three bins, put non-decomposed material into two of the bins while you dig out compost from the bottom of another. (The bottom of the heap, the oldest part of the pile, is where all the good black stuff is.)
• In a small city garden or a tiny plot attached to a condo, a single compost heap made from pallets, stacked concrete blocks, or chicken wire stretched around some stakes driven into the ground works. But if you have to look at it every day, you may want to invest in a sleek, tidy commercial unit—these units also keep out various vermin.
Hot or cold?
The system you choose also depends on whether you want to do cold composting or hot composting.
• Cold compost rots at a relatively low temperature. It develops after a year or two of collecting leaves, clippings, and other waste and leaving the pile alone. It helps if you add moisture (or protect it from too much moisture) and turn it occasionally, but it will still break down even if you never touch it. Cold composting is sometimes called passive composting.
• Hot composting, sometimes called active composting, requires paying attention to the ratio of brown materials (carbon-rich things like autumn leaves and dried-up perennial foliage) and green materials (nitrogen-rich waste such as grass clippings and green foliage). Hot compost also requires correct moisture levels—moist but never soggy, and enough space to stockpile green and brown materials so you can mix them together in the right ratio.
• You can also let worms do your composting (called vermicomposting). You’ll need to keep a container of specially purchased red wiggler worms (not earthworms from the garden) evenly moist at an even temperature and feed them kitchen and yard waste. The worms don’t produce a lot of compost, but they give a rich, valuable blend of compost and worm castings for the garden. Vermicomposting takes up little space, so you can compost indoors in a closet or the corner of a heated garage.
Volume control
The composter you choose also depends on how much material you want to compost. Perennials that need to be cut back every spring and autumn leaves each fall can all add up. If you have a very small amount of waste—some grass clippings, two or three bags of autumn leaves, and a steady supply of kitchen waste—a one-bin system will work.
Choosing a composter
•Traditional multi-bin system
o Ideal for: Gardeners with lots of space who don’t have to worry about the appearance of their compost heap.
o Advantages: Can handle lots of plant materials and waste. Ideal for cold composting.
o Disadvantages: Takes up a lot of space. With some bins, you have to take them apart to get to the compost on the bottom. Not necessarily attractive.
o Cost: Free if you use salvaged materials. Wire bins are about $25 to $50 each. Up to $400 for store-bought all-wood kits with three bins.
• Rotating bin system
o Ideal for: Dedicated compost junkies who want a constant supply.
o Advantages: Can handle lots of plant materials and waste. Ideal for cold composting.
o Disadvantages: Can’t be used alone—you need a holding area to store raw materials.
o Cost: $125 to $300.
• Enclosed bin system
o Ideal for: Small-space gardeners.
o Advantages: Contained, tidy-looking. Usually rodent-proof, depending on design. Container helps control moisture.
o Disadvantages: Handles small volume only. Best for cold compost.
o Cost: $25 to $175. Free if you use salvaged materials. Wire bins are about $25 to $50 each. Up to $400 for store-bought all-wood kits with three bins.
• Wire or flexible plastic cyclinder
o Ideal for: Gardeners who like to compost smaller amounts in a variety of spots around the garden.
o Advantages: Assembles in a snap. Easy to lift to reach compost at the bottom. Portable so you can position in various spots around the garden, such as behind shrubs, for temporary compost piles.
o Disadvantages: A bit flimsy; bends and cracks over time. Can tip if not partly buried or anchored.
o Cost: $20 to $50.
• Worm box or bin
o Ideal for: Avid composters, especially those in temperate climates who are able to compost outdoors.
o Advantages: Can be used indoors or out. Compost includes highly beneficial worm castings.
o Disadvantages: Worms must be kept at 50°F to 75°F. If you’re not fond of worms, there’s the “ick” factor. In cold-winter climates, must be done indoors, limiting the amount of compost produced.
o Cost: Worms cost around $20. Box or bin is free if made with salvaged materials; otherwise $75 to $300.
Veronica Lorson Fowler is a garden writer in Ames, Iowa.