Initial Sheet Mulching

Wowza! It has already been a week since we began to build the soil at the Tefft House! It’s about time I fill you guys in!

Before we start putting in new plants next spring, it is important to build rich, healthy soil so the plants have all they need to succeed. For most, it is pretty standard to dig up the grass on the lawn, and till in compost. For those practicing permaculture, this standard approach is not ideal for a few reasons. First off, soil is not just minerals and nutrients; soil is alive. Trillions of microorganisms form symbiotic relationships with plants’ roots underground, and soil life carries out many functions in an ecosystem, including playing crucial roles during nitrogen fixation. Disturbance of these organisms’ habitat via tilling is not beneficial to the ecosystem we’re trying to create. The goal is to foster growth, not to create stresses. Tilling also causes erosion, or soil loss, which is exactly the opposite effect we’re going for. Aeration and decompaction of the soil can instead be accomplished by simply taking a pitchfork, inserting it into the ground, pulling back a bit, and repeating for the entire area. At the Tefft House, the lawn had already been professionally aerated as a part of regular lawn maintenance. Secondly, all that grass on the lawn is a resource that can be composted into soil. It doesn’t make much sense to let it all go to waste. This is where sheet mulching comes in. In order to utilize the potential in the grass, sheets of newspaper or cardboard are laid down on top of the lawn to prevent sunlight from striking it, and thus beginning the decomposition process. Then a layer of compost is laid down, and then finally mulch. Some people find putting down compost first, and then cardboard or newspaper, and mulch on top is more successful. Others suggest laying down any other compostable items, like leaves or vegetable scraps, before the layer of cardboard to decompose with the grass. Any of these variations on the process will build soil, but here’s how we went about it:

It was recommended to me to sheet mulch in the fall, or very early spring, to have the most successful results. The design hasn’t begun yet, but it was important that the soil be built up to replace the lawn in the fall, so there is time for composting during the winter. The main priority was to determine locations that were not to be sheet mulched. Although the majority of the front yard will become a garden, a small section of lawn will still remain a functional space for the owners’ grandchildren and dogs. Other spaces in the garden that will not need to be sheet mulched are the active and reflective social areas: a small patio and gazebo. Some preliminary observations revealed some patterns that informed where the best garden zone is likely to be, and thus the best areas to avoid sheet mulching. The most direct sunlight shines on the south side of the property, so to avoid shading, any high structure, like the gazebo, should be on the north side. Likewise, a patio area with tall screening from the highway would also be on the north side. And for the lawn to be placed efficiently, close proximity to the house (“Zone 1”) is ideal since the occupants will be walking there multiple times per day. Marsha had expressed that she’d like the remaining lawn to be in a shape of a circle, so we came up with this:

Plan for fall sheet mulching.

To lay out the plan, we used landscaping paint and a measuring tape.

Marking the mulch boundary around the patio area.

For the circle, we measured 10 feet on a cord to serve as the radius, and then my Dad stood in the center of the circle while I swung around, keeping the cord taught and spray painting as I went along.

West half.

East half.

The gazebo is an octagon with a radius of 4 feet. We found an online geometry calculator that informed us each of the 8 sides must have a length of 3 feet. We used a measuring tape to mark 4 of the sides 4 feet from the center, each 3 feet long, and then connected the remaining 4 sides.

The octagon gazebo.
There is some debate about exactly how safe it is to consume vegetables that have been grown in soil composted with inked paper products, so to err on the side of caution, any cardboard with ink printed on it went around the edges and on the north side. The south side of the land, which receives the most sun for annual production, was covered in newspaper (contains non-toxic, soy-based ink generally) and the backs of used notebook pads (ink free).

To keep the newspaper from blowing away with the wind, the pages were soaked with water from the hose.

It’s also good form to be sure any cardboard that does get laid down is free of any tape or staples, and refrain from using the glossy ad paper from the newspaper.

After the sheet layer comes 3 inches of compost. We measured the consistency of depth with this simple tool:

This is just a small piece of wood with a sharpie line drawn at 3 inches.

And finally we topped it all off with a layer of mulch, just enough to completely cover the compost. In the spring, we will use this as a blank slate to build upon.

Kendra and Blake hard at work.

The wind was giving us quite the fight during this section. Layers would fly up into the street with one gust of wind, even with the cardboard soaked in water. We had to modify our procedure to keep them in place. First, someone laid down the cardboard, overlapping an inch or two. Then it was sprayed with the hose, and immediately a small amount of compost was added on top to add extra weight. For good measure, we then moistened the compost with water again. This seemed to work well, although it slowed our pace.

With all this commotion on Broadway, it was time to put up the sign. First, we had to dig post holes. The soil was very dry and compact, so it was a bit of a challenge. But with water, and some patience, it went up.

My Dad and Eric digging the post holes.

Drilling the sign to the posts.

We didn’t quite finish up the entire lawn; the front most section on the west side with a steep slope is yet to be completed. But all in all, a very productive weekend! A huge thank you to everyone who came out to help!!

Up next is the design! It was so exciting to watch the front lawn change, and I’m looking forward to the full transformation. For another example of sheet mulching, here’s a link to the UMass Permaculture Garden YouTube video on the subject.