Fig 1.
The EG gardens and their yields per square metre per 30 days.
Table 1.
Comparison of average yields (kg/m2) and (kg/m2/30 days) among previous research and the EG results.
These results were calculated for the previous studies.
Fig 2.
The seasonal proportions of the total harvest quantities from each of the method-crop categories.
Table 2.
All monitored garden-related activities and time spent on each1.
Fig 3.
Scatter plots of the negative correlation between area under production and the inputs and outputs.
All values are presented as per square metre per 30 days. The lines represent the upper envelope of the results.
Table 3.
Significant results from comparisons among the garden size categories.
Fig 4.
The WUEgross, WUEnut and WUEfin results for the garden size categories.
The blue circles represent the WUEgross and WUEnut values of the two gardens from the Cleveland et al. [5] study as previously calculated in [16], while WUEfin results have been adjusted to the 2018 AUS$ value. The pale grey band represents the global average WUEgross scores for ‘vegetables’, ‘roots and tubers’ and ‘fruits’ from Mekonnen and Hoekstra [36].
Fig 5.
A comparison of the WUEgross, WUEnut and WUEfin scores for each of the five main method-crop categories.
Outliers are identified by the arrows, and the chkn-egg WUEnut scores required its own axis. The additional yellow lines on the WUEgross chart represent comparative WUE values of related foods from Mekonnen and Hoekstra [36]. The grey band represents the estimated WUEgross range for chicken eggs (irrigation only) as based on a brief review of online poultry keeping websites.
Table 4.
Significant results from WUE comparisons among the method-crop categories.
Table 5.
A comparison of the median input, output and WUE results of each of the five main method-crop categories.
Table 6.
A comparison of the related costs and time required to break even for each of the five main method-crop categories.
Table 7.
Results from comparisons in ongoing costs and labour requirements among the method-crop categories.
Table 8.
Comparison of the Edible Gardens survey question on households saving money and a similar question from the 1975 Adelaide study by Halkett [39] on household fruit and vegetable requirements.
Fig 6.
A progression of the setup, 1-year and 5-year net position of the different garden size categories (N = 34).
Table 9.
Percentage distribution of the calculated time to break even.
Fig 7.
Net return (m2/30 days) plotted against labour (m2/30 days).
Additional lines represent the lower (AUS$5/hour), Australian minimum wage (AUS$18.93) and upper (AUS$30/hour) bounds of the returns for labour.
Fig 8.
Comparison between the net return curve modelled by Ward & Symons (2017) and the upper net return envelope of those EG gardens with more than 3 months of data (N = 28).
Fig 9.
The impact of applying a wage rate to invested labour and how this impacts the net position of the EG gardens.
Fig 10.
Comparison and ranking of the five main method-crop categories by their inputs and outputs per square metre per 30 days.
The number of stars represent the best performers in that category.
Fig 11.
The nutritional content and retail value of the four food types.