Raining on the Mulch

Google images will reveal all colors of disgusting molds that grow on mulch, but the key growth is almost microscopic.

When our helper and I finished all the mulching - I promise - for this year, I thought. "We should hose it down." Sometimes his children come along to help, so I was ready for them to help - with a suitable length of garden hose and a brand new nozzle. We had plenty to do and no children to help, so the mulch stayed dry...for a few hours.

That night we had a heavy rain, enough to build a puddle across Scott Street (my rain gauge). Aha, I thought, the mulch has started to rot.

The idea behind mulch and straw bale gardening is the decomposition of the medium. I did not think so at first. I imagined that mulch would hold moisture in the soil (true) and prevent wind erosion (also true). I understood that soil creatures liked shade rather than blazing sun (beyond dispute), but I wanted wooden mulch to last forever. No wonder they sell people on various non-rotting media - even plastic "weed barriers" that make weeds worse.

Contact with the soil will begin the rot. Leave a log on the ground and it will look the same for years, but underneath it is eaten away by fungus and soil creatures, leaving its inside soft enough to crumble with a little finger pressure.

The newsprint layer is a bit of a barrier, but mostly there to block the sun and hinder weed growth. Newspapers are sponge-like in absorbing water but they let air through, so they foster decomposition.

From Emlab:
Fungi do not ingest their food like animals. Instead, they release enzymes into their surrounding environment to break down complex materials into simpler ones that can be absorbed by the fungus in a process known as absorptive nutrition. For these enzymes to leave the fungus, remain functional and to break down complex substances, water is necessary. Once the complex substances have been broken down and dissolved in water they are absorbed by the fungus.

I want the fungal strands (hyphae) to attack the wood and begin feeding the broken down chemicals into the soil. The rain promotes the growth of other microscopic creatures, so they prosper together and generate more biomass. The biomass (all creatures great and small, the Lord God loves them all) holds nutrition in the soil in a vast Vanity Fair of buying, trading, and crafty swindles.

I consider sacks of mulch to be soil amendments. I do not have to rototill mulch into the soil to get the effect, because God's Creation takes care of the distribution. Rototilling would wreck the system that goes into action for all decomposition.

Did I have to rototill the lawn to plant spinach? No, I mulched and waited, then opened a section for planting, with all the grass and weeds rotted into the top layer, serving as cafeteria for earthworms, bacteria, protozoa, and nematodes.



I have garlic bulbs to plant in the rest of the row. As hardy bulbs, their cloves will grow into fresh garlic bulbs for the spring.