Lessons in Permaculture #011

This is the eleventh installment of a multi-part series on permaculture. Future installments of Lessons in Permaculture will be posted at a rate of one or two per month. Be sure not to miss upcoming installments by subscribing to the Sustainable Future website (it is free, of course). The sign-up box can be found at the top of the website's right-hand column.

Lessons in Permaculture #011

Another important principle of permaculture, as identified by David Holmgren, is to Use Edges and Value the Marginal. In his e-book, The Essence of Permaculture, Holmgren says this:

"Tidal estuaries are a complex interface between land and sea that can be seen as a great ecological trade market between these two great domains of life. The shallow water allows penetration of sunlight for algae and plant growth, as well as providing forage areas for wading and other birds. The fresh water from catchment streams rides over the heavier saline water that pulses back and forth with the daily tides, redistributing nutrients and food for the teeming life.

Within every terrestrial ecosystem, the living soil, which may only be a few centimetres deep, is an edge or interface between non-living mineral earth and the atmosphere. For all terrestrial life, including humanity, this is the most important edge of all. Only a limited number of hardy species can thrive in shallow, compacted and poorly drained soil, which has insufficient interface. Deep, well-drained and aerated soil is like a sponge, a great interface that supports productive and healthy plant life."

As many of you may know, one of my many career hats is that of a research technician. I have assisted on a number of biodiversity studies over the last decade or so. Most of my work has been with arthropods. I know from personal experience that the edges between two habitat types are incredibly diverse in terms of the amount and diversity of life. The amount of insect life in the edges between forest and field, for example, is much greater both in diversity and in raw numbers than deep within the forest or the field themselves. Wherever two or more habitat types meet, that is the place where field biologists want to be.

In my yard, I try to take advantage of this natural productivity boost by building hedgerows. And I increase the margin, the edge, by not building them in straight lines, but in curvy, "S" patterns. Let's say that I have two points, A and B, that are forty feet apart and I want to build a hedgerow between them. If I build the hedgerow straight from point A to point B, I get forty feet of edge (my hedgerows are on the edges of my property, so I am only counting one side of the hedgerow in this discussion). However, if I include lots of curves and out-croppings, I can actually squeeze in sixty feet or more of edge into that forty feet.

My hedgerows consist of small fruit & nut trees and berry bushes for food, various herbs for spices, teas and other uses, native wildflowers to encourage and support native bees, butterflies and other pollinators, as well as some thick evergreen bushes and some flowering trees such as dogwoods to provide nesting areas and shelter for birds and other wildlife. I also use the fallen leaves each autumn for my compost heaps and layers for my lasagna gardens, and collect any fallen twigs and branches to use as kindling.

More on Hedgerows

I've written a couple of essays on hedgerows in the past as part of my forest gardening series - On Verges and Hedgerows and Building Hedgerows. Check them out for lots of tips, info, photos and resources.

Hedgerows only touch on one possible application of this permaculture principle. Needless to say, this and every other principle can have many different aspects and applications to consider. Entire books can be written on each principle. These essays are only intended as starting points to get you thinking of how to apply permaculture in your life.