Growing Avocados in the Desert Posted on February 23rd, 2010
THE APPLES and ORANGES of AVOCADOS
The following guidelines for growing Avocados were paraphrased from a
presentation by Julie Frink at the California Rare Fruit Growers, Inc.
Festival of Fruit in September 1998 at Balboa Park in San Diego,
California. My own observations are in Italics. Her title, “Avocado,
Cultivars and Care” reflects a long association with the industry in
Southern California. The data presented are germane to avocados of any
variety in any locale where the fruit can be grown. A small number of
healthy avocado trees presently growing and producing in the Salt River
Basin are evidence that avocados, while probably not a commercial
viability, can survive in home landscapes in the Phoenix area.
AVOCADO: CULTIVARS AND CARE
The many cultivars of avocado have been divided into three
“horticultural” races, West Indian, Guatemalan and Mexican. Numerous
other varieties are hybrids of the three. Mexican fruit is smallish,
smooth skin, large “tight” seed with leaves and flesh that have an
anise odor and taste. Seeds generally do not run true but the Mexican
variety has a better chance of doing so.
Mexican is the hardiest rootstock to use to graft other
varieties. We don’t yet know if that is true for this area; we
believe it is.
Avocados require good drainage. Standing water is always fatal.
The tree likes full sun but exposed boles on young trees should
be protected from sunburn. Paint with white latex. Adult tree trunks
are usually fully shaded with their own foliage. If defoliation
occurs at any time for any reason, immediately paint all exposed
bark with white latex.
Trees may be heavily pruned for height. Pruning doesn’t hurt them
unless new or previously protected stems or trunk are exposed to
direct sun.
Avocados are subject to severe salt burn. (A critical fact in the
Salt River Valley with saline irrigation water and alkaline soil.)
When planting, Julie sets the pot on level ground then builds a
compost mound around it. After the mound has settled in, she removes
the container and replaces the tree in the hole. One could plant in
a raised-bed over gravel for the same effect. Avocado roots are
relatively shallow. Basin chimneys aid drainage where it is bad. If
leaf tips turn brown from salt, The root zone should be flushed to
reduce salt concentration. A layer of mulch will reduce the
concentration of salt by evaporation in the root zone but may also
keep the soil too wet. Do not mulch in the winter.
Avocado sex is unusual. Well, kinky? There are types A and B and
an oddball or two that may fall somewhere in the nether. A typical A
or B alone will set enough fruit for an average family. A scion from
a B may be grafted to an A or visa versa for cross-pollination.
Planted in close proximity, either type is more productive. Most
common varieties are distinctly an A or B. All Avocado flowers have
both male and female paraphernalia. “A” flowers open in the morning,
receive pollen and close. They open again the afternoon of the
following day and release their pollen. “B” flowers are receptive to
pollen in the afternoon but don’t release pollen until the morning
of the next day. Julie said the female pistil is a prominent feature
and male parts are the little “fluffies” in the middle. Pollination
requires insects.
Young trees require shading to avoid sun damage.
Compiled by Dick Gross, Founder of Arizona Rare Fruit Growers
