Nut trees
In many climates there are wild and cultivated nut trees from hazel, to pine nuts to pistachio. Whether you live in a temperate, mild, sub-tropical or tropical environment there will be a nut tree you can grow. The only trouble will be below hardiness zone 4 you would struggle to keep it alive.
Nut trees originate from all over the world and can be grown in cooler climates with some varieties only growing in zones 10 and above for any real production. Soil type and potentially local varieties should also be a consideration when growing trees. This means trees that may have natural immunity or a treatment viable for diseases and known pests with a range of fixes. Trying something new may mean a learning curve and regular attention, also be aware if any varieties could be an invasive species if unmanaged or seeds dispersed by birds.
Typical issues can be fungus, mould, coddling moths and squirrels/chipmunks/mice, however, specific varieties may be more prone to one or the other.
Cold tolerant nuts
These trees can tolerate temperatures down to zone 4 (-28 degrees Celcius). sweet chestnuts, Hazel, pecan, pine nuts and walnuts. If you live in zones 4 - 6 the production from trees may be much lower than zones 7 - 10.
Trees will start to flower in spring, however, walnuts can flower until the next year. Nuts are produced September - October or November in warmer areas.
There are different varieties of trees, for example, American and European hazel or black, English and white walnuts. The variety may depend on where you live or stocked cultivars at garden centres and nurseries. Many countries have a list of plants that they consider invasive or unwanted so check on a local government site or plant forum. Alternatively you can ask a local nursery.
Temperate nut trees
Trees in this category can be grown from zones 7 - 10, especially when kept relatively frost free. Almond, pecan and walnuts do well in these zones. Although pecans and walnuts appear in the previous category, due to the severe frosts that can occur in zones 4 - 6, crops will be limited, especially for walnuts.
These trees flower from spring and produce nuts for the autumn from September through to late October. Many people associate almonds with Brazil nuts but they are suited to lower temperature than warm climates as opposed to Brazil and macadamia nuts.
Warmer climate trees
These nut trees prefer warmer climates from zones 9/10 - 13, which are relatively frost free with hot summers. The nuts in this category will take more heat and sunlight to ripen. Brazils, cashews, macadamias, pistachios all need the warmth. Often associated with Austtralia, California, the Mediterranean or South America where they grow well nut can also be suitable in southern Asia, Africa, channel islands, warmer western Europe, Pacific islands and central America.
Again if these trees are not locally grown check with a garden centre, nursery or government website for species considered invasive. These trees will flower in spring and produce nuts from early autumn. However, as these are tropical please not that southern hemisphere summers are December - February.