Sept 8th, 2013

Andrew:


As Lindsay wrote about a bit earlier in the year, we are in the process of designing our communities "Zone 1", the area immediately around our main gathering and living spaces - the physical environment we interact with the most.

view of the East facing side of the spiral

In general, we are looking to create both gathering spaces, as well as space efficient, food/fuel/medicine producing systems that serve to create a luscious and wind-sheltered environment for us to live and gather in.

One nifty feature we added to this garden space is a mollison-style herb spiral.

Like circles, Spiral's are naturally space efficient. You can get more of bed space in relationship to footprint when utilizing a vertical spiral shape than if you where to use two dimensional liner forms.

Spirals also helps to maximize the productive use of the fertile "edge" space in the bed. The edge space is the area where two distinct media meet.

In the case of the spiral, and many garden beds, it is the area around the outside of the garden bed.

In general, the edges of systems tend to be more productive and diverse that the interiors of them. There are interactions and dynamics present at the edges of things, at the meeting of distinct media, that are not present in more homogeneous.

One of the most simplified ways of explaining how to go about designing an ecosystem that has the productivity and resilience of a natural ecosystem is to maximize the amount of productive edge space in the system. To plant diverse species, with diverse forms, and add structural features that enhance the growing space.


spirals have the same area as circles but greater edge space

Often times in gardening, the edges of the beds have more undesirable "weeds" than the center. I reckon this is because the materials used to edge the bed help to create beneficial microclimates that are more sheltered, wetter and more heavily mulched.

With the herb spiral, we wrapped the exterior edge in on itself, so that the plants we are wanting to grow can make use of that beneficial microclimate.

Because it's three dimensional, you are also making use of vertical space, providing more bedspace, and facilitating good drainage of the top soil areas, and easy harvesting. It also creates several microclimates for growing herbs that prefer varying degrees of light and moisture.

view of the west facing side of the completed spiral

Herbs that like drier soil can live at the top, and those wanting more moisture live at the bottom where water naturally collects.

Herbs that like more sun can live on the south and east facing sides, those that like more shade or milder sunshine can live on the north and west side.

Since we are trying to provide herbs for a whole community, our herb spiral does not have the diversity of herbs commonly found in a "single family" spiral.

Instead, we decided to plant the spiral with three perennial herbs in larger quantities. Thyme, Oregano, and Rosemary.

Other culinary and medicinal herbs will be found throughout the rest of the herb-garden growing spaces.

Making the Spiral


Digging up a storm.

First Faun, Katy and I removed all the top soil from the area and made a separate pile for it.

It's important not to mix together the different soil horizons! It's taken a long time to form concentrated top soil, and you can undue all of that really quickly with a few scoops of the shovel.

Then dug a circular hole into the clay subsoil about 1 foot deep.

I then began placing the foundation stones that will form the supporting structure for the spiral.

I then made sure the courses were well packed in and wetted down. Laying successive courses one on top of the other.

To make the spiral, I did not lay stones all the way to the outside edge of the wall. Instead, stopping short a few feet with each course.

Overall there were 5 courses to the wall. 1.5 of which ended up being burying by the backfill.


The first course is laid in.

I incorporated a large amount of organic material into the heart of the herb spiral, to help give it a greater moisture holding capacity, and to help water more easily infiltrate to the bottom layers of soil

We back filled around he outside of the spiral with clay subsoil to help prevent weeds from spring up in unwanted places. We we able to incorporated most of the high-quality topsoil into the bed, along with the extra organic material.


wetting everything as I go so we can plant in it right away.

All in all, the plants at the top of the spiral will have about 4 feet worth of good soil to reach down into, and the lowest levels of plants will have at least one foot of soil.

Looking forward to seeing how well this feature works out.