Weeds or useful medicinal plants in the rural home garden?

Background. Traditional medicines remain an important health-care service among African indigenous cultures. In South Africa, medicinal plant use (bark, roots, bulbs, and herbs) threatens biodiversity and the sustainability of this informal industry. Several realities have stimulated experimental and adaptive management research into cultivation of key high-demand medicinal plant species in and around the home gardens of poor rural communities for domestic use and for trade: declining supplies, localized extinctions, increasing market prices, and economic opportunities for commercializing traditional medicinal products. Objective and methods. This paper reviews three recent South African studies aiming to create alternative medicinal plant resources to reduce dependency on the dwindling wild resources: commercial production of medicinal crop plants; chemistry of wild versus cultivated plants, and of bark versus leaves; and growing of forest tree seedlings in rural home gardens. Results. Cultivation trials and chemical testing indicated that different agricultural treatments suit each species differently in terms of either rapid growth rates, strong chemical concentrations, or both. Wild-harvested plants of some species have stronger chemical concentrations than cultivated plants. For several tree species, the bark and leaves contain the same active components associated with healing. Conclusions. Successful propagation is not dependent on elaborate and expensive equipment and technologies, but rather on some basic principles of plant growth and methods of manipulating these under controlled conditions. An alternative cultivation method for tree species is the production of leaves as opposed to bark. Cultivation could be done successfully at the school, in home gardens, and in production systems in the village.