Orchid mycorrhiza fungi (OMF) play a part in the mineral nutrition of both seedlings and adult orchids. Thus, OMF can substantially reduce the chemical fertilizer requirements of orchids. OMF also increase resistance and tolerance of the plants against root pathogens, secrete growth-promoting substances and most importantly, reduce transplant shock from in vitro to in vivo conditions. Dendrobium plants inoculated with OMF have higher growth rate, produce more bulbs and keikis, and bear flowers earlier and longer and with more flower spikes compared to uninoculated ones. OMF can be applied by mixing a small amount of inoculant in the soil before repotting.