Ask a Farmer: How do you Maintain your Compost in the Winter

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By Gael Minton, Acequia del Monte del Rio Chiquito

Gael Minton and husband Ty are the owners-operators of Squash Blossom Farm (SBF), a 2.2 acre parcel of historically irrigated land on the Acequia del Monte del Rio Chiquito in Taos, NM. They have operated SBF since 2001. In New Hampshire Gael helped start a CSA (Community Supported Agriculture) and after gardening for 2 summers in Taos, she started SBF-CSA & Apiary, which is now in its 13th season with 17 member families plus the Minton family. Gael believes small farms are the backbone of a healthy community and is encouraged by the revival of local agriculture in Northern New Mexico.

Question: How do you compost and/or maintain your compost pile in the winter?

Composting is an age-old worldwide method of utilizing field biomass/dry crop residues, animal manures, green hay and kitchen waste to increase soil fertility and water retention and to decrease soil erosion. I have been composting for my gardens for 45 years in 4 states: Vermont, Maine, New Hampshire and New Mexico. Conditions are very different in the high altitude arid state of NM from the 3 wet New England states. New Mexico soils are rich in minerals but very heavy with clay and compact easily. Organic matter like compost rich in microbial activity must be added to loosen the soil so that plant roots are supplied with oxygen, nutrients and water.


In northern NM, it is important to protect compost from drying out during the spring, summer and fall seasons by surrounding the piles with hay bales or covering compost rows with heavy carpet and occasionally adding water. The compost process requires moisture and heat to break down dry materials (carbon) and kitchen waste, grass clippings, green hay and animal manure (nitrogen). I aim roughly for a balance of 30 parts carbon/dry brown materials to 1 part green nitrogenous materials to obtain nutrient and humus rich compost.


The activity of millions of different microorganisms (microscopic, living, single- and multi-celled bacteria, some fungi) and larger organisms including animals like rotifers and worms can take place in a cold pile or a hot pile. Finished compost, complete breakdown of all the materials to a soft dark brown fresh scented mix, can take from 6 months and up to 18 months depending on heat, moisture and turning/mixing of the pile. In order to inactivate pathogens in animal manure a pile must reach a temperature of 130°F and up to 170°F for 3-4 days after each addition of manure before spreading on edible crops. The process of breaking down materials occurs if there is a relatively steady temperature of 120°F for prolonged periods during the growing season. Breakdown biological activity continues at a slower pace in lower temperatures.

In early winter, I continue to add in layers of kitchen waste, hay, manure and dry crop debris that I clip, crush and break into small pieces. Some farmers use a shredder. Before frost settles in to the piles, the temperature is between 40°F-50°F and it is possible to dig a trench or a hole in a pile to bury kitchen waste and to mix materials. Later as the piles become frozen and covered with snow, I cover the kitchen waste additions with hay and sometimes a tarp and discontinue any digging or mixing.

In early spring, late March, I turn the piles down to the most decomposed layer to expose the unfinished materials to the billions of living organisms for digestion. When the piles are fully thawed in late April and early May, I fork off the top 1-2 feet of un-decomposed material into the bottom of an empty bin and roughly screen the finished compost to turn in to the vegetable and flower beds. I dig out my compost bins every 12-18 months and begin again.


Making compost for a backyard garden or a small farm is very rewarding because all organic materials have a place and a purpose. Nothing is sent to the landfill. Even large animal bones can be used to line the bottom of a compost pile or buried in a deep hole on the edge of a field. Creating an environment for healthy plants and fruit trees requires building and maintaining healthy soil through cover-cropping, rotation of crops, adding compost, keeping ground covered with perennial herbs, native shrubs and mulch as well as leaving some parcels fallow for a period. Unhealthy plants and trees are an indication that soil is deficient or out of balance. In addition to the soil practices mentioned, remedies might include soil and compost testing. The two most important aspects of a healthy farm and garden are living soil and plant diversity.

Among my favorite references: The Soil and Health Albert Howard, Teaming with Microbes Jeff Lowenfels & Wayne Lewis,
The New Organic Grower Eliot Coleman, andA Biodynamic Farm Hugh Lovel. For practical composting tips: Gardening the Southwest Carole Tashel and Compost Clar