Avocados are large fruit that are classed as berries. They grow on evergreen trees that can reach heights of 40 to 80 feet tall, according to the University of Hawaii. The avocado tree is native to tropical and subtropical areas in Central America, from Southern Mexico through Guatemala. As tropical and subtropical plants, avocado trees need warm, mild weather in which to thrive. Avocado varieties are split up into three main groups.
West Indian avocado trees are native to tropical lowlands so they needs warm climates in which to grow well. Young trees can only handle a chill down to 28 degrees F, while mature trees can handle 25 degrees F. It blooms from February to March and the fruit matures in about five to eight months, from May to September. The West Indian avocados are one of the largest, usually from 1 to 5 lbs. in weight and have smooth, dark green skin. The West Indian avocado has a low oil content, but the trees have the highest salt tolerance. Purdue University lists some West Indian cultivars as 'Pollock,' 'Ruchle,' 'Russell' and 'Waldin.'
The Guatemalan avocado is native to tropical highlands, and the young trees can hand chills down to 26 degrees F and mature trees can handle 24 degrees F for short periods. This type of avocado blooms from March to April, but the fruit does not mature until almost 10 to 15 months later, from September to January. The Guatemalan avocado varies in size from ½ lb. to 5 lbs. They have rough skin and a medium to high oil content in the fruit. Some Guatemalan cultivars, according to Purdue University, include 'Edranol,' 'Hazzard,' 'Pinkerton' and 'Tonnage.'
The Mexican avocado tree is also native to tropical highlands, but it is more cold hardy than the Guatemalan type. Young Mexican avocado trees can handle temperatures down to 24 degrees F while the mature trees can handle down to 18 degrees F. They flower from January to February and the fruit matures six to eight months later, from June to October. Mexican avocados are the smallest as they are all either 1 lb. or under and they have smooth skin and a medium to high oil content in the fruit. Purdue University lists some cultivars of Mexican avocados as 'Ganter,' 'Gottfried,' 'Mexicola' and 'Puebla.'