Composting in a Drum

By Dr. Francis Gouin

Making compost in a drum composter is very different from making compost in a bin on the surface of the ground. When you’re composting in a bin on the ground, any excess water drains from the compost into the ground. Any moisture released in the air surrounding the pile is quickly disbursed by wind and air currents.
Composting drums have vents, but most of the moisture released during decomposition condensates on the surface and drops back into the composting materials. As temperatures increase, more water is carried by the warm air.

Knock Them Onion Tails Down

If you planted onions this spring, it will soon be time to knock those onion tails down if you want to extend their keeping quality. As soon as the onion tails begin to turn yellow, knock them down by using the back of a steel rake. Or do what commercial onion growers do and drag a log over the bed so that the onion tails are lying flat on the surface of the ground. By knocking down the tails, you will be preventing the spores that cause neck rot from entering the space between each onion tail.
After you have knocked them down, allow the onions to remain in place until the tails dry. If we get a wet spell, you can harvest the onions and hang them under a roof until the tails dry.

   Once that moisture exceeds 60 percent, the system becomes anaerobic. Anaerobic conditions create strong odors, acid and alcohol. This problem can be solved by feeding dry leaves, shredded paper, peat moss, hay or straw into the composting barrel to absorb the extra moisture. The composting mass should be moist but not wet.
   If you are going to add crab chum (blue-crab waste generated from eating crabs), add an equal amount of peat moss or pine bark mulch to the composting barrel. Crab chum tends to be wet with viscera, and crab shells are basic or alkaline in nature. The peat moss or pine bark will not only absorb the extra water but also neutralize the alkaline crab shell because both peat moss and pine bark are acid in nature.
   Peat moss or pine bark keep odor down and provide efficient composting conditions.
   Composting drums do not function well during periods of cold weather. The entire composting system is surrounded by ambient air, and there is insufficient volume to maintain minimum temperatures for microorganisms to function. Unless you are monitoring the composting drum two or three times each week and turning the drums at least weekly, the contents can quickly develop strong odors, especially if you keep adding fresh vegetable matter regularly.
   Year-round composting in composting drums can be achieved by moving the units into a small greenhouse or into an insulated garage. In a warm atmosphere, temperatures of 140 degrees can be measured for several weeks in an active composting drum. During my years of research with composting drums, I was able to heat a 40-foot by 60-foot glass greenhouse during the winter months using six composting drums. When the system was working well, it was impossible to keep my hands on the surface of the drums because they were so hot.

Ask Dr. Gouin your questions at [email protected]. All questions will appear in Bay Weekly. Please include your name and address.