Doing site analysis is one of the first steps in designing an Edible Forest Garden. Obviously you have to know what can be grown in your area before figuring out what you will try to grow.
I had always known that there was an interesting East-West divide in the greater Melbourne region where the east would get more rain. Turns out that Werribee is a particularly unusual area. It gets the lowest annual rainfall of any location south of the ranges. On average, the area gets only just under 500mm of rain a year. About 40% less than eastern suburbs. More interesting still, it’s about 40% less rainfall than locations only 30 to 40kms due north. This puts the climate in the semi-arid category as far as rain goes. In general, the climate can be categorised as somewhere between semi-arid/Mediterranean and warm temperate.
Next step was soil analysis. I found a very useful site from the Victorian Government by which I gather that the soils in my area are of a sandy clay loam. Pretty good. What’s been interesting is the variety of soils on the property itself. In the back south-east corner, there was significant topsoil which was dark brown, friable and loamy. Only 5 metres to the west was the browny red sandy loam mentioned on the government website. And just 10 metres further north of that was a hard, rocky section that had very little topsoil at all. In any case, the pH is consistent across my property with readings mostly between 6.5 and 7.
My block faces N-NW, is dead flat and gets full sun all year round. In addition, there is a very large peppercorn tree in the neighbours house due south which provides very nice protection from any southerly winds and also some nice free mulch. However, the property is very open to cold winter northerlies and hot summer northerlies. I aim to mitigate this by planting some windbreak trees on the nature strip and have also taken other design measures to counteract it.
With that basic analysis in mind, I turned to figuring out exactly what plants I wanted in my garden. Starting with the trees which produce food that I already eat a lot of seemed sensible. My initial list of desirables therefore included macadamias, almonds, avocados, apples, pears, lemons and olives. I also had many other exotic and enticing examples on the list but, in the end, I have elected to focus on the main crops I am sure to eat. As such, I’ve mostly planted at least two of the trees just mentioned. Sometimes there are necessary reasons for this (eg. requiring pollinators for apples and pears) but I also think it’s a good strategy to mitigate the risk that a particular tree or a particular location in the yard might lead to low yields or outright failure to survive or produce. It also means that there are less variables overall and I can try slightly different approaches with each tree to see which works best.
In any case, I’ll put here my initial three backyard designs. None of these ended up being much like what I’ve ended up with and they reflect a basic assumption that I later discarded (more on that in a later post). Nevertheless, they give the gist on how I went about the initial designs and they are quite similar to what is recommend in the Edible Forest Garden books.