The Size of a Full-Grown Avocado Tree
Avocados are native to Central America and probably were first cultivated in Southern Mexico. As a semi-tropical understory tree, avocados grow to a medium height, reaching up to 60 feet (18 meters) in the largest recorded specimens.
Avocado trees also naturally grow broad and wide, spreading laterally to a width up to 30 feet (9 meters) with multiple lateral branches and leaves, creating shade under the canopy.
However, careful pruning of avocado trees produces trees smaller in stature with a smaller diameter canopy.
Most avocado trees reach full-size and begin producing fruit in 7 to 15 years.
Factors Affecting Size of Full-Grown Avocado Trees
Besides pruning for keeping trees small, the type of soil the tree is planted in, the amount of fertilizer, and irrigation practices also affect the ultimate size of the tree.
Avocado trees grow to their largest size when planted in humus-rich, well-drained soil with a neutral or slightly acidic pH level.
When planting new trees in heavy, clay soil, digging a planting hole approximately 6 feet (1.8 meters) in diameter and 2 feet (.6 meters) deep and filling it with loamy soil or a mix of sand and native soil, allows the tree to develop a better root system and grow larger.
In areas with very poorly drained soil, installing a French drain connected to the planting hole may be necessary, if you want the tree to grow to maximum size. Poorly drained soil can lead to disease problems in the roots, keeping the tree small and unhealthy. You can also build up a mound of soil to raise the roots out of wet conditions.
Growing the tree in a container also limits the ultimate size. Terracotta containers with a diameter of approximately 2 feet (.6 meters) or larger allow for good aeration of roots while also keeping the full-grown tree to a modest height and width but still growing large enough to produce fruit.
How much you fertilize the tree also affects size and vigor. Avocado trees thrive when they receive several applications of fertilizer each growing season. Liquid fertilizer can be applied along with irrigation water, or the trees can be top-dressed with a granular type of fertilizer.
Organic fertilizers which provide moderate amounts of nitrogen, phosphorus, potassium, and trace minerals include:
- Fish emulsion
- Blood meal
- Fish meal
In order to grow to full size, avocado trees need regular watering in warm and dry weather. Generally, trees need deep watering once or twice a week during the growing season. Letting the soil dry slightly between watering helps prevent disease problems in the root system.