Growing Avocados

Although sprouting the seed is simple, the plant may not bear fruit for up to 15 years. Commercially, avocado trees are propagated through grafting, which means the stem of one avocado variety is spliced onto another avocado variety.

The technique yields quicker harvests (within 3 to 4 years), a consistent fruit quality and disease-resistant avocado trees. Pollination, climate, soil, water and diseases are among variables that affect growing a healthy, fruitful avocado tree.

Climate
The condition most limiting to growing an avocado tree is cold weather. All three primary avocado species, the West Indian, Guatemalan and Mexican are all tropical plants. Mostly all avocados grown in the Philippines is of the West Indian specie while the Hass variety is a Guatemalan Mexican hybrid. Worldwide, the Hass variety dominates 80% of the export and local markets.

Soil, Water and Fertilizer
An avocado tree can grow successfully in a variety of soil types and in soil with acidic or alkaline pH levels, but the tree requires soil that it must have good drainage. It declines in poorly draining and saline soil. Because West Indian varieties are more salt-tolerant than Mexican varieties, they are better choices in coastal regions. An option is to plant a Mexican variety that is grafted onto a West Indian rootstock. Although an avocado tree cannot tolerate wet soil, it needs at least 1 inch of water every week during periods of insufficient rainfall. Not fertilizing the tree until it is 1 year old is recommended. Young trees need four applications of a balanced fertilizer, such as 14-14-14, and older trees need twice-yearly applications of a high-nitrogen product applied in early summer and late winter.

Diseases
Avocado root rot is the most serious disease of avocado trees. This disease, which is caused by the pathogen Phytophthora cinnamomi, thrives in poor drainage conditions. Pale leaves, wilted leaves, branch die-back and small fruits are consequences. Applying a layer of gypsum and a 4- to 6-inch layer of an organic, coarse mulch underneath the avocado tree’s canopy but several inches from the tree’s trunk supplies calcium and suppresses the development of root rot.