Only Brazil nuts are cultivated. Wild Brazil nuts are the most economically important non-wood forest product in the Amazon basin. Despite its name, the biggest exporter of nuts in Brazil is actually Bolivia, where the nut is called Brazil nut. Both rural and Brazilian Bolivians rely on collecting and selling nuts from Brazil as their primary source of income.
The felling of naturally growing trees in Brazil has prevented deforestation for this reason in many areas of the Amazon. Brazil's walnut trees (Bertholletia excelsa) are the only species in the monotypic genus Bertholletia, named after the French chemist Claude Louis Berthollet. While some use equipment or shake trees by hand to release the nuts, most harvesters wait for the trees to drop theirs before picking them up. The walnut tree, which is a variety of American walnut, can grow to over 130 feet, with a thick truck that can be over 6 feet in diameter.
The harvest is done by shaking the trees (manually or mechanically) to loosen and drop the ripe nuts from the tree. Growing your own Brazil nuts will require a bit of patience, and while difficult, it's a rewarding endeavor. Like many nuts, almonds grow on small trees, about a foot wide at the trunk and up to about 12 feet. Peanuts are by far the most consumed tree nuts in the world, more than 45 times more than almonds, their next favorite.
It can take up to three years before a cashew tree starts producing nuts, but up to eight years produces enough cashew nuts to be sold. Because of this, although attempts have been made to plant trees in Brazil, natural cultivation has proven to be more reliable. Because climates are different from country to country, the time when a specific nut is harvested in each country varies. Pecans are usually harvested between October and November, as the trees collect walnuts that have fallen from the ground.
If you take them from the bag of shelled blended nuts mentioned above, you won't be able to spread them. Walnuts are harvested in early to mid-autumn, from September to November, shaken or dropped from the tree and then picked where they fall. Hazelnuts, or more specifically Filberts, are mainly cultivated in Mediterranean climates, although warmer climates in other countries also produce them, including the United States and China.