Brazil nut trees are one of the more difficult types of nut-bearing trees to reproduce. They need full sun while they're seedlings and saplings, and it can take close to 2 decades before a Brazil nut tree begins actually growing Brazil nuts. Native to South America, the Brazil nut tree is one of the largest trees growing in South American rainforests, and undisturbed, they can live from 500 to 1000 years.
Part of the reason Brazil nuts are so difficult to grow is because they rely on a very particular and undisturbed rainforest ecosystem.
Preserve an area of rainforest where Brazil nut trees can sustain. If the area has been decimated, allow several years for the ecosystem to rebalance. A recent New York Times article has noted that rainforests regenerate much more easily than previously imagined (see Resources below for link).
Find an expert on rainforest plant biology, or a native expert on Brazil nut trees. Contact the Association of Brazil Nut Exporters for help with this.
Locate a Coryanthes vasquezii orchid, which attracts orchid bees that are capable of pollinating the Brazil nut flowers. When they are present near a Brazil nut tree, then natural pollination will occur.