The classic, buttery fruit of the avocado tree (Persea americana) is a boon to the backyard garden, but before you take the time and expense to plant and nurture this delicate tree, make sure you have enough room. While avocados aren’t huge trees, they do grow to a considerable height quite quickly.
Avocados are also called avocado pear and aguacate. There are three types in the species -- Guatamalan, Mexican and West Indian -- divided on the basis of origin, ripening time, skin appearance, oil content and cold hardiness. They are now grown all over the world in tropical and subtropical areas. A delicate evergreen, avocados are winter hardy in U.S. Department of Agriculture plant hardiness zones 9b through 11. In many yards they provide shade as well as fruit.
Height and Shape
Avocados can reach a full height of between 30 and 65 feet, with a canopy width of 25 to 35 feet, but it's more common to see them 30 to 45 feet in height. Canopy shape is usually regular, symmetrical and smooth, meaning branches and leaves fill the crown in uniformly. Avocado trees also look quite similar from one member of the species to another. While younger and middle-aged trees grow in more of a pyramidal shape, avocado trees become progressively more rounded as they get older.
Avocados have a fast growth rate, and can add 2 feet or more to their height in a single growing season. Assuming an avocado tree reaches a full 65 feet, you can expect it to hit maturity in roughly 20 years, perhaps less. When struck by freezing temperatures, avocados may die to the ground; if they survive, they will rebound with the same quick growth rate. Although the difference is only a few degrees Fahrenheit, mature trees can tolerate colder weather than young and still growing trees.
You may prune your avocado tree any time of year when you want to improve its shape, remove damaged branches or reduce its height. However, you should keep heavy pruning to a minimum except in late winter or early spring. This will stimulate the tree to produce more twigs and leaves -- vegetative growth -- at a time when they can harden off before the cool months return. Although you can control tree height by pruning, removing large branches will encourage the avocado to grow taller.