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Small-scale traditional agricultural ecosystems, commonly known as homegardens, were studied in the semi-arid central and the humid southwestern parts of Ethiopia. Hundred homegardens, with fifty in each of the two areas, but otherwise randomly sampled, were scored as being in pioneer, intermediate or climax stages. In the southwest, the percentage of climax gardens was 11% above country average, while in central Ethiopia it was 10% below average; the opposite was the case with intermediate gardens; the percentage of pioneer gardens was nearly the same in the two areas. Qualitative information recorded from observation of gardens at different stages was used to discuss general trends in the development of homegardens. In central Ethiopia homegardens are generally established outside agricultural land, often on stony or rocky ground ear-marked for living quarters, while in the southwest homegardens are usually established in forest clearings where useful forest plants are deliberately retained in situ. Microhabitats diversify as the homegardens mature, vertical and horizontal patterns develop, and the diversity of cultivated species increases, as well as the range of variation in horticultural, physiognomic and phenological features. The vertical structure and complex intercropping is more developed in homegardens of the southwest, while there is more emphasis on the horizontal structure of the homegardens of central Ethiopia. Homegardens in southwestern Ethiopia utilise many species of the natural ecosystem and recruit promising new crops through an open-door strategy, which facilitates geneflow between spontaneous and homegarden populations of crop species, as well as with their wild relatives. Conservation can learn a lesson from traditional management of rural homegardens in southwest Ethiopia, but these homegardens will no doubt be poorer if the surrounding natural forest continues to disappear.