When we began our incremental move back in December, we had a few days each visit to accomplish what we could. My number-one priority was gathering leaves from beneath the maple trees to mulch an area for the garden. My husband and I raked 10 heaping trailer loads and spread an 8-inch layer over 1,800 square-feet of ungrazed pasture.
The soil beneath was red clay– intimidating to tame for a first-year garden. Plus it had long been growing grass with no manure return. I worried about being able to add enough organic material to sustain our vegetables.
Several weeks later I spread several barrels of compost and re-covered the earth with leaf mulch. Then in March, we dug our first potato trench, and I was amazed at the improvement, already. The soil had darkened and become more granular. The smell was lovely and the shovel sliced in easily. The grass and weeds beneath the mulch had died off and broken down into the earth.
In April, we mowed the field and spent a day raking grass clippings to add another layer of mulch, as the leaves had broken down perfectly.
Now, in only six months of mulching and doing little else, we’ve converted inert clay to rich garden soil. The areas that lack mulch are rather like concrete, since exposed clay essentially bakes into bricks.
We’ve seen mulch in action. Here’s why it works so well:
Mulch protects the worms and microorganisms and allows them to do their work of breaking down organic material. Soon the bottom layer is converted to rich humus.
It prevents evaporation, allowing water to nourish the plants rather than vanish into the air. This makes mulch an essential element of water conservation in this time of drought on the West Coast.
Mulch also retains heat in the winter months, protecting roots from frost, and cools the soil in summer. Especially important for plants like tomatoes, which are susceptible to fungal problems, mulch prevents splash-back when watering (don’t water the leaves!).
Finally, mulch is the best possible way to suppress weeds. With no chemical sprays– even organic sprays can do damage to the soil and surrounding plants– nutrient-hungry weeds are simply smothered and turned into compost.
While we used leaves and grass clippings, there are a multitude of options for how to mulch.
Wood chips are a huge reservoir of nitrogen, an asset to the soil as it breaks down. The process takes longer than other mulches, which can be a positive or a negative.
Bark dust and straw are great options, but keep in mind that hay– as opposed to straw– can contain grass and weed seeds that may add to your troubles.
Pine needles, as well as some leaves, have a high acid content, so check your pH before applying, or use them only on acid-happy plants like blueberries. Lime can be applied to raise the pH if necessary.
Plain brown cardboard or a thick layer of newspaper– the ink is soy-based– topped with bark or other mulch is especially effective against weeds. Simply cut holes where vegetables or flowers will be planted.
At the end of the season, mulch can simply be tilled in to decompose and return its nutrients to the soil, or new layers of compost and mulch can be added on top for “lasagna gardening,” a popular no-till method.
For more information on lasagna gardening, read:
Building Soil with Lasagna Gardening at Homestead Honey
Lasagna Gardening at Learning and Yearning
3 Great No-Till Gardening Methods at Northern Homestead
Lasagna Gardening at New England Permaculture Homestead