Monday, April 29, 2013

An edible forest garden

Back in March, Susan and I did a weekend course in Melbourne with US edible forest garden expert Dave Jacke. A fun, informative weekend it was too: Dave's knowledge of all things edible and forest-dwelling is remarkable. His two-volume work Edible Forest Gardens must surely be the most detailed, informative book on the subject yet written.

But what is an edible forest garden?

An edible forest garden is an example of ecosystem mimicry. Observing a complex, self-sustaining forest ecosystem, understanding its key elements, interrelationships and processes and attempting to replicate them using plants which are human food crops.

At its most basic, a forest ecosystem might comprise:
  • canopy layer – tall trees that need full sun
  • understorey layer – smaller, shade-tolerant trees and shrubs
  • herb layer – herbaceous perennials
  • groundcover layer
The idea of edible forest gardening is to fill all of these niches with plants that are edible or otherwise useful to gardeners, and to do it in such a way that competition is kept to a minimum and mutually beneficial (symbiotic) relationships are maximised.

That's a very rudimentary attempt to describe the theory; now for the practice!

A year ago Jill and Mike removed four cypress trees from their garden, leaving a grass-covered space about 20 x 8 metres. That much real estate right next to The Patch was not something I could ignore, and so I came up with various ideas to fill it, including a large polytunnel and various animal husbandry schemes more suited to a 10-hectare farmlet, before hitting on the idea of … you guessed it: an Edible Forest Garden. Henceforth known as the EFG.

Jill and Mike have been good enough to indulge my new passion, and we're starting on the EFG this winter. Here's a plan showing what the EFG should look like after about 8–10 years:
Click image for a larger version
The coloured circles represent the trees and shrubs. Informal bark paths provide access for harvesting (and wandering around) and also break up the area into patches, each of which will be dominated by one or more combinations of herbs and groundcovers.

The choice of trees and shrubs was determined to some extent by what's already in Jill's and Mike's garden: they have a wide variety of fruit trees, and there seemed little point in planting more of the same. Carob is a stately, pyramid-shaped evergreen tree from the Mediterranean area and will increasingly dominate the site visually. The design mimics an open woodland rather than a closed-canopy forest, with the tree and shrub layers covering less than 50% of the area.

When selecting the species I also attempted to bring together plant communities that would work well together and to this end I compiled a table with the key characteristics of the species I was looking at.

It will be interesting to see how far the reality of this Edible Forest Garden comes to resemble the plan!
Click image for a larger version

No comments:

Post a Comment