January 26

1 - Winter composting is possible in New Mexico, but care must be taken to keep the compost moist and to manage other factors important to maintaining the composting organisms.

Yard and Garden January 19, 2013

Q.

My compost pile has not reduced in size much this winter. In October I raked up all my old leaves, pine needles, and dead plants and piled them up to make compost. I was hoping to have plenty of fresh compost in time for spring planting, but now I am not expecting much compost. Is it possible to create compost during the winter from the autumn garden debris?

A.

This has been a difficult winter in most of New Mexico and the conditions were not optimal for composting. However, it is possible to compost garden and landscape wastes through the winter, but you must pay close attention to certain factors to optimize compost formation.

The most important factor for winter composting in New Mexico is maintaining adequate moisture in the compost pile. The lack of precipitation has made it necessary to frequently add water to the compost pile. The materials you mentioned putting into the compost pile are fairly coarse materials and, unless you shredded them to reduce their size, they created larger air spaces and channels between the particles in the compost pile. This is good for providing much needed aeration (to provide oxygen needed by the composting organisms), but it also allows for rapid heat loss (slowing composting) and rapid drying (also slowing the composting process). Addition of water will help maintain the activity of composting organisms, with will generate heat in the compost pile to counter the cold temperatures effects on composting. Shredding the material will help hold heat to speed composting, and help slow water loss. You can add water just as water, or you can puree vegetable wastes from the kitchen in a blender and add this puree to the compost pile. By adding the puree, you will add water and a food source with a large surface area (due to the puree process)to speed the activity of the composting organisms.

Another factor to consider when composting is that there must sufficient nitrogen (from green wastes, manure, kitchen vegetable wastes, or fertilizer) to properly feed the organisms breaking down the garden wastes to make compost. The materials you mentioned (dried leaves, pine needles, dried plant material) are all low in nitrogen. They are a good source of carbon containing materials needed for composting, but low in nitrogen.

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: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

Links:

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.

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