Comparing this year to previous years it is clear that 2015 has been the most productive so far. There has been about three times as much produce as past years, with the exception of 2011 which had a major potato crop (I planted the whole front garden with potatoes to clear it).
Interested in how productive the garden is per unit area I came up with a figure of 7.24 ton/ha. I've found it hard to come up with good numbers to compare this with, but I've seen 31 - 40 ton/ha quoted for high intensity allotment growing so the garden is less productive than an allotment, but then it is much lower maintenance too. I've also got some numbers for agricultural production at around 3.7 - 7.8 ton/ha so it's near the top end of that. As AnniKelsey pointed out in her blog recently, it's not just how productive you are per unit area, but how productive you are per person. On that basis I'm very pleased with the garden this year.
Thinking a little more broadly about the role for forest gardens and the type of produce they can yield, I'm starting to think that they make a lot of sense as a low-maintenance use for back gardens and public spaces. They can complement higher intensity allotment and other forms of growing to provide a diverse range of local food as well as their myriad of other benefits, not least the aesthetic ones. Hopefully these productivity figures add a little weight to that argument. I'm going to keep on recording and see what next year brings.