California avocado trees are unique from other fruit trees. Unlike deciduous fruit trees, which have defined seasons and go dormant annually — avocado trees are subtropical/tropical fruit trees that never go dormant. In other words, they are always growing and developing — even in winter (growth/development is just slower then). Understanding this simple fact — that avocado trees do not go dormant — is just one critical factor in understanding how an avocado tree grows and how that affects your productivity and profitability.
This section outlines the basic facts about California avocado trees and provides California avocado growers with an overview of the critical two-year growth cycle of avocado trees.
To begin with, we start with a few basic facts about the avocado tree.
- Avocado trees are broad-spreading trees (this is important to know as regards pruning).
- The most productive leaves grow on the outside of the avocado trees and they contribute the most to the tree.
- Avocado trees bear fruit on peripheral new growth.
- Avocado trees require nutrients in order to grow and support their avocado fruit crops. Sugars, nutrients and hormones are transported from the top of the avocado tree to the roots using phloem tissue. Some nutrients, like water, hormones and mineral nutrients move from roots to top of the tree via xylem cells.
- Irrigation is critical to avocado trees because they do not search for water and the roots are only in the top six inches of soil under the canopy. This top six inches of soil has a tendency to dry out and can stress the tree because healthy avocado trees need moist soil. At the same time, avocado tree roots are sensitive to water logging and can drown, so careful irrigation calculations must be made (www.cimis.water.ca.gov/cimis/welcome.jsp).
- Avocado flowers are modified shoots and various flower tissues (petals, stigmas, anthers) are modified leaves.
- Avocado flowers occur in a much-branched group (compound inflorescence).
- Each flower has male and female parts that open on different days. The female phase usually occurs the day after the male phase.
- Blossoming occurs from late winter through early summer, but most harvested fruit develop from flowers that are pollinated during two months in spring.