Thanks, decomposers

With the May Day spotlight on under-valued workers, I’m grateful for the work of decomposers in the garden. Last fall I lamented my depleted compost supply. Now I’m rejoicing to see lots of fresh compost in my bins. This strengthens my impression that compost is like sourdough starter, full of what’s needed to reproduce itself. Once you’ve got the process going, it gets easier and quicker over time.

Under a layer of fall leaves in the bin, I found new compost

    That’s despite my lazy woman’s composting approach. I just pile on the garden waste as it comes. I don’t turn the piles or bother balancing the amount of “brown” high carbon and “green” high nitrogen materials. Compost still happens.

Adding fall leaves to a bin I emptied last fall

    Composting is central to my garden. With a renewed supply of compost, I’m ready to add some oomph to the perennial beds by improving soil from above—no need to dig in that extra organic material, because soil organisms will incorporate it.

Things go better with compost

    I’ll also save some compost for making homemade potting mix. By mixing it with coir, or coconut fiber, I make peat-free potting mix that works just as well as the bagged stuff I used to use for container plants.

Peat-free potting mix: because harvesting peat contributes to climate change

    In 2011, I had my compost tested for biological activity by Soil Food Web, a lab in New York. I highly recommend this experience. The lab reported the populations of the types of organisms in my compost sample: bacteria, fungi, protozoa, and nematodes. They calculated the ratio of fungal to bacterial biomass and observed that the compost was mature, bacterial-dominated, and becoming more fungal. 

     I even got a note, “One of the better compost samples I’ve seen in a while. Keep up the good work.” The only caveat: “Need to work on nematode diversity a bit more.” To that end, they recommended inoculating the pile with forest duff, the mix of half-decomposed material that lies on the forest floor. You can bet I did that right away.

Beneficial nematodes thrive on the forest floor

    Looking out at the thick layer of fall leaves I left on the beds last fall, I recognize that the whole garden depends on the same work these small organisms do in the compost pile. It’s often said that without the work of detritivores--animals such as earthworms that take in, break up, and digest dead stuff—and decomposers--bacteria and fungi that absorb nutrients from dead materials--we’d be living on top of huge piles of dead animals and plants.

    I don’t just count on these small organisms in the compost bins. They’re also hard at work building soil and turning fallen leaves into leaf mold. The wood chips that I spread on paths and around trees and shrubs last a long time, but they too are broken down, predominantly by fungi that can digest lignin, the polymer that makes wood rigid and resists rot. Without those fungi, I’d have everlasting mulch, but it would do a lot less for the underlying soil.

Wood chips would be around forever without decomposing fungi

    Composting is just a half-domesticated way of speeding up what’s happening all around us, thanks to those unseen workers.

As soil organisms break down fall leaves, they make good soil for spring flowers