December 26, 2015
1 - There are alternative methods of composting available to New Mexico gardeners during the winter.
Yard and Garden December 26, 2015
I saw your article about composting in the winter in New Mexico and wanted to offer some suggestions:
A useful approach might be to distinguish the two composting processes: Hot & Cold - The hot method (actively managed) generates internal heat as the microorganisms transform the carbohydrates in the feedstock. This method requires specific intention & method in order for pile to heat up & sustain the heat. The operation must be turned & churned so that oxygen is available to a high energy process. The pile is only slightly influenced by the ambient air temperature.
A cold method (can be static or actively managed) sometimes called "Dump n Run". In this method there is no intention to generate appreciable, sustainable heat, although hybrids are possible, for example "warm piles".
The operation temperature will vary with the ambient air temperature, but will balance out over the 12 month seasonal temperature variations. Insulation of a "cold" operation may be useful. Once the pile temperature goes below 50F there is a slowing of microbial activity, but it does not stop. So, yes continue to add feedstock in winter months.
Another option for the question is the Bokashi bucket method which could be started indoors in winter, then buried in the soil at an appropriate time.
- John Zarola
New Mexico Extension Master Composter
Thank you for writing, John. I stayed with information about a heated compost pile in the previous article due to limitations on space during this season when advertising is an important part of newspapers. I also wanted to stay with the hot compost piles for that topic because such piles are best for reducing potential problems with diseases and weeds in the garden. However, I do use the "Dump n Run" method you described (though I had never heard of that name - I like it!). This relies on the fact that "compost happens". It is a natural process and things will decompose naturally, even when we do not closely manage the process. I also use the Bokashi bucket method to dispose of things indoors and infrequently add them to the outdoor compost. These are great techniques and I am very thankful that you mentioned them.
A variation on the "Dump n Run" that I like is the "post-hole composting" technique in which a series of post-holes are dug in the garden before the ground freezes. Kitchen wastes can be put into these holes and covered with a foot of soil (to keep animals from digging) through the winter. If the holes are covered or filled with straw until adding compost, at a depth of one foot or greater the soil temperatures will remain warmer, allowing decomposition through the winter. However, such composts are not maintained by turning. They are more in the line of what the Pilgrims were taught about putting fish heads in holes under corn seeds. The results will be similar.
John also shared with me a composting website that New Mexico gardeners may want to use: www.nmcomposters.org. He recommends looking at the "Desert Composting" link on the left column. There is good information there for gardeners wanting to compost or to improve their compost. Thank you, John.
Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: firstname.lastname@example.org, office: 505-865-7340, ext. 113.
For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.
Please copy your County Extension Agent and indicate your county of residence when you submit your question!