Tried making compost and failed? Wound up with vermin instead of garden food? We asked Paul Paddock, a partner in Sonoma Compost, to give us the low-down on some common composting concerns.
Q. Do I have to buy a composting bin to make compost?
A. There are several reasons to consider the use of a compost bin:
In regions with significant rainfall, a compost bin can prevent compost from becoming saturated. When compost becomes waterlogged, the process can slow down or stop — causing the materials to become anaerobic and generate unpleasant odors.
Containers can help small compost piles retain heat in really cold regions.
Containers can help confine your compost pile to a specific part of your yard.
Some containers are designed to make it easy to turn the organic matter as it composts.
Containers can help discourage rodents or small animals from grazing on your composting scraps.
Q. What can I put in my compost?
A. When making compost and composting yard trimmings, the ratio of carbon- and nitrogen-rich materials is important. An easy way to achieve the optimal mix is to blend roughly equal parts of carbon-rich “brown” materials such as dead leaves, straw, sawdust or chipped branches with “green” materials such as freshly cut grass or recent prunings of green foliage from your garden. Get more tips here on what you can put in your compost.
Q. Doesn’t all that food in the compost bin attract mice or get smelly?
A. Not if you do it right — but don’t let that intimidate you! You don’t have to hand-hold your compost daily. If you don’t follow a few basic rules of thumb, compost can indeed attract pests like mice, or start to stink. But if it does, just resume good compost “hygiene” and your compost will get hot enough to deter pests and prevent offensive odors.
Check for these five most common causes of backyard composting problems to troubleshoot any compost misbehavior:
1. Too much of a good thing. Efficient composting requires the correct ratio of carbon- and nitrogen-rich materials. In the summer, compost piles often contain too much freshly-cut green grass, resulting in an anaerobic goo that’s neither pleasant or likely to compost. A fall blend of too many dead leaves can result in a pile that’s carbon-rich and nitrogen-deficient. These problems are easily adjusted by adding more of the needed carbon or nitrogen material. Here’s a useful tip: Save a portion of your fall leaves in tightly closed waterproof containers or bags (make sure they’re thoroughtly dry first) so you can keep adding them into your compost bin during the summer months when dry, brown materials are in shorter supply.
2. Materials added are too big. Large, woody branches will not readily decompose. On the other hand, if everything in your compost recipe is ground or chipped to a very small size, your pile will settle tightly on itself as it decomposes and will lack the porosity that allows oxygen to reach the interior of your pile. The composting process will often slow down or halt. Strive for an average particle size of between 1 and 2 inches.
3. Too wet or too dry. Organic materials generally compost most efficiently in a moisture range of 50 to 60 percent. A good rule of thumb is to keep your pile moist enough so it glistens, but isn’t dripping wet.
4. Lack of oxygen. The microbes that are digesting your organic blend are living creatures that need oxygen to survive. Provide them with a pile of organic matter porous enough to allow air to move into the sides of the pile during the heating process. And don’t forget to turn your pile when it begins to cool. This ensures an adequately oxygenated pile.
5. Not enough compost in the bin or pile. To keep an aerobic compost pile at optimum composting temperatures requires a pile with enough mass to heat up and stay warm through the night and during cooler seasons. Typically, in a backyard, a pile at least one cubic yard (3' X 3' X3') in size will be sufficient.
Q. How often should I turn the compost?
A. If you don’t have a compost thermometer and don’t want composting to be too fussy or involved, just turn your compost or spin your composter every couple of days. So long as you’re not attached to having finished compost in 30 days flat (more on this below), you don’t have to get that technical about it.
If you want to play by the book, use a 24-inch thermometer (available through garden supply sellers). When temperatures go below 120 degrees, it’s generally time to turn the pile. Follow the directions that came with your compost bin or thermometer.
If you create your pile with the right ratio of carbon-rich to nitrogen-rich materials materials, keep moisture content optimal, and have a sufficient amount of compost collected in your pile or bin, your pile should rapidly reach temperatures in the 140- to 150-degree Fahrenheit range.
Be sure to turn the pile so that the outside parts end up on the interior, ensuring that all parts of the pile are exposed to the hottest area. Commercial composters generally maintain temperatures over 131 degrees F for at least 15 days. Because home composting typically happens under less consistent conditions, yours will likely take longer.
Q. How long will it take before I can use the compost on my garden?
A. This depends on how your compost pile or bin is created and maintained. It’s possible to get fairly finished compost in three to four weeks if you’re diligent about maintaining the right blend of materials and moisture and you’re turning the pile every day or two. But most backyard gardeners find they get better compost and enjoy the process more if they take a leisurely, philosophical approach to their efforts.
The fact is, nature is composting plant life all around us at a pace that’s often measured in seasons rather than weeks. And the compost that results is as good as it gets. So I suggest tuning in to the natural rhythms of your garden and compost pile. Appreciate that fine compost, like fine wine, may take a little longer but is well worth the wait.