Soft, buttery and full of nutrients, avocados have been included in meals for centuries. Avocado trees are thought to have originated in Mexico, and European explorers are credited with carrying them to other warm regions with mild winters, like Hawaii and Florida. Guatemalan, Mexican and West Indian avocado species exist, as do hybrid forms of those types. In cooler climates, they can be grown indoors in containers. Three specific growth phases characterize these evergreen trees.
The tree prepares itself for the following season's crop. Floral differentiation occurs in the spring. Avocado flowers bloom in late spring and early summer. The blooms are panicles that include 200 to 300 small, yellowish-green blooms. Each panicle produces up to three fruits, although a report by the South African Fruit Growers' Association states less than 1 percent of all flowers develop into fruit. Therefore abundant flowering is not necessarily indicative of a large crop.
Bees and other flying insects are usually pollinators of an outdoor-growing tree. Some out-of-season blooms may appear and grow fruit. Some varieties bloom and set fruit in alternate years.
Flowering continues. Bees and other flying insects usually serve as pollinators of flowers, which can be successfully pollinated for only a few hours when they are open and in the female stage. Many flowers open as males only. Cooler temperatures can inhibit pollination by discouraging flowers from opening and bees from being active.
Following flowering, the fruit begins to set and drop, taking about 3 months. Their size and color varies by variety, with West Indian types producing large fruit that weigh up to 2 lbs., Guatemalan types growing medium-sized pear-shaped fruit and Mexican trees growing small fruit weighing up to 10 oz. Growth is slow and selective. Fertilizing at this stage will encourage good fruit set and development.
As the fruit drops, it begins to grow more rapidly and its eventual size is determined. More tree watering encourages fruit growth because the trees tend to draw water from the fruit as it matures. Drought periods will stunt the fruit sizes because of this. Vegetative growth also occurs, encouraging growers to apply fertilizer. Phase 3 ends when the fruit is mature and their growth reaches an apex. Harvesting occurs at this time.