With our local weather bouncing around all over the place, I took advantage of a short break between storm fronts to do some outdoor chores. Like checking on the over-wintering plants and re-filling bird-feeders. And a favorite, turning compost.

There are four large compost bins sitting side by side against a south-facing block wall in the back yard. Each is built 30 x 30 x 24″ (inside diameter) using stacked cement blocks and topped with a framed, wooden top to keep out neighborhood critters. They’re not very pretty nor as efficient as some of the ones seen in gardening magazines, but they serve.

The bulk of my yard waste comes in the fall when the flower and vegetable beds are cleared. The morning glory and tomato vines, the pulled up green beans, peppers and squash all head for the piles. My neighbors donated bushels of damaged apples. I carefully layered with other materials to balance the mix.

If you live in almost any other part of the country, then a pile of this sort would decompose in a matter of no-time-flat. Here in Santa Fe, however, is yet another aspect of “The City Different”. Rotting requires moisture. Since my bins are not sealed, the contents require watering and mixing, so the stuff on the edges doesn’t dry out and sit there in perpetuity.

An archaeologist some years ago showed me a corncob she pulled from a packrat nest–a perfect little popcorn-sized cob. ‘This is what corn looked like in the 1300’s’, she said. The packrat had tucked the cob into a spot out of the wind and weather and it had stayed happily intact for 600 years. My tomato vines would threaten to do the same were it not for my efforts.

A common high-elevation mushroom, Hawk’s WIng

In our wilder landscape there is only Mother Nature to turn the compost piles. It seems more chaotic to us perhaps, but the system works over its own timescale. At higher elevations, there is somewhat more moisture. Soil fungi thrive in riparian (stream side) locations and north-facing slopes. On south-facing slopes where the sun warms and dries the ground more, a greater accumulation of debris may appear. This becomes self-mulching, and a little breakdown of the lowest layers may occur during moist periods.

The lower in elevation one goes, however, the drier it is. Less snow and rain, more sunshine, relatively higher temperatures. Grasses and other plants rely on soil bacteria more than fungi to release nutrients from dead material. But it’s not an efficient system. Local nutrient starvation is evident where “rings” of grass appear, the clump dead in the center. A pile of stiff tumbleweeds (see previous post) stacked high against a fence can persist in the drying wind for a very long time.

Two weeks re-growth in native grass after fire.

The big recycling system here is wildfire. The plant structures and compounds (like terpenes) that would resist breakdown by other methods are obliterated by fire, releasing their simpler elements to the soils. Dramatic, far-reaching, and ruthlessly efficient. Fire is the big re-boot for us in the Southwest.

Short of torching my backyard, though, I’ll have to rely on subtler methods. When the temperatures warm a bit, I’ll be out to my compost piles with the watering can to cheer on my bacteria and fungi.