[Arid_gardener] Question from Home-Hort WWW page

Wed Nov 28 13:47:24 MST 2007

Pauline, seeds make lovely trees and every seed will eventually set fruit 
but it could require five to ten years to reach maturity and bloom. The 
resulting fruit may or may not be fit for consumption unless you graft or 
bud a known variety on it. In that case you may get fruit identical to the 
scion the second or third year. It is, unless you want to experiment or just 
do things the creative way, best to buy a grafted tree from one of the local 
nurseries. Plant it in full sun but get out your phone book and start 
calling. Any cultivar will do okay here, in my opinion, but all are frost 
tender and will need protection if you are in a cold spot or if a rare cold 
spell hits your area.

There are eight or ten seedlings bearing edible fruit around the valley but 
I have lost track in the past several years. That is how I know, without a 
doubt that, with the right care and luck, Avocados will procuce here but 
don't invest your life savings in an orchard.

Attached is an article and several email responses from the Arizona Rare 
Fruit Grower's club that might help you get started. If any trigger 
questions, don't hesitate to inquire.

Dick Gross, Sec/Ed AzCRFG
Arizona Rare Fruit Growers

----- Original Message ----- 
From: Dick Gross
To: File, Dick Gross
Sent: Friday, April 29, 2005 12:05 AM
Subject: APPLESandOranges of Avocados

http://www.azrfg.org/

Ciso:
The trick with irrigation is to keep the leaves turgid without excessive 
water and anaerobic conditions in the root zone, a condition that suffocates 
the tree and encourages rot. With feeder roots compromised, they cannot keep 
pace with transpiration and leaf cells with insufficient liquid collapse and 
wilt is apparent. When foliage appears limp and loses luster, you can be 
reasonably certain the organism needs a drink. If wilt reaches the point of 
no return, the leaves drop exposing the bark to sunburn. Avocado foliage, 
like citrus, grows naturally all the way to the ground limiting the amount 
of direct sun exposure of thr stem and branches to a safe level. There may 
be small windows through openings in the foliage but those exposures migrate 
in correlation with the suns movement across the sky. Avocados require full 
sun to bloom and set fruit but it is necessary to start them in Arizona 
bright morning sun with afternoon shade until the root system is established 
well enough to keep pace with transpiration that is also its cooling system, 
if this amateur perceives it correctly.
Dick Gross, Secretary/Editor
Arizona Rare Fruit Growers.

Your information was very good.  Stewart is a possibility.  It is the best 
Mexican variety.  The seed is small and the fruit is usually excellent, 
handsome and about 8 oz in weight.  An odd year occurs now and then where 
the fruit has too much fiber but this has been rare for us. The tree usually 
has both female and male flowers so is a good pollinator.  Some avocados 
hold their fruit better if they are pollinated by a different variety.  Some 
like Reed set fruit and hold it for over 1 1/2 years with no pollinator at 
all. Gwen produces heavily with a pollinator but hardly sets fruit at all 
without one.  I'd recommend trying the Stewart if it can be found in the 
area.  It is not unusual at nurseries here but sometimes is hard to find.  I 
am really not sure of its cold hardiness but since it is Mexican and doesn't 
hold fruit over Dec. Jan. and Feb. it may be worth trying.  Fuerte is pretty 
cold hardy but blooms early and if the nights (or the days) are cold will 
often not produce female flowers.

Julie Frink

_____________________________________________________________________________

ARIZONA RARE FRUIT GROWERS

A CULTIVAR OF THE CALIFORNIA RARE FRUIT GROWERS, INC.

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. We know of three trees in the Tucson; one seedling 30+ 
years old and fruiting in a Benedictine Monastery courtyard and two fruiting 
Zutano varieties in a member's yard.

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, Secretary/Editor Arizona Rare Fruit Growers Email; 
rkgross3 at cox.net

MISC. NOTES ON AVOCADO
AB: The germination percentage of avocado seeds, mainly the Mexican race 
Indio (Desert), was significantly higher when the seed coats were removed or 
the seed tips were sliced off, as compared with sowing intact seeds. Peeling 
plus tip slicing gave better seed germination than peeling alone. Removing 
slices from the sides of the seeds also improved germination. The optimum 
stage for carrying out germination counts to assess treatment differences 
was 33 days after sowing.

VARIOUS RESPONSES TO EMAIL INQUIRIES:

AVOCADOS IN THE SALT RIVER BASIN?

We know of 5 full-grown, healthy, fruiting avocado trees
started from seed in the Phoenix area. They are 20 to 30 years old and
15 to 20 feet tall. The homeowners say the fruit is good although I
haven't yet had a chance to sink my teeth into one. We know, however,
that seedlings don't run true and quality would vary. There are
undoubtedly others we have not located. If you know of any, please let
us know. We theorize that a good way to find out what will survive here
is to look in front and back yards to see what is already growing.

All avocado flowers, classified as A and B (with a whole bunch falling
in between) have both male and female parts. A difugalty is that an A
flower will open as a female that can receive pollen but its own male
parts refuse to give it up. The B flower at that time won't receive
pollen but its male component generously yields pollen to an insect that
makes it available to the A flower. The next day, they reverse the role.
Having said all that, I suggest you forget it. There is enough overlap
to supply the needs of an average family. If you have both an A and B,
all other things being equal, you could get a heavier but not guaranteed
fruit set.

If a given tree is defoliated, scratch the bark lightly just above the 
ground level. If there is green, assume some life remains but don't bet too 
heavily on it surviving. If a shoot shows up below the graft union, the 
resulting tree will not be the one you bought. Its fruit is likely to be 
edible, nonetheless, if you nurture the shoot from the base stock to 
adulthood, a period that could vary from 10 to 20 years. That shoot can be 
used to graft again, however, and get fruit in four or five years from the 
graft.

Avocados are sensitive to salt and wet feet will kill them readily. They
must have good drainage, controlled flood irrigation to flush salt from
the root zone and well managed mulching to prevent evaporation from
accumulating salt in the root zone. If drainage is questionable, they
can be planted on a mound or in a raised bed. Drainage vents filled with
rounded river rock can be drilled in the outer edges of the planting
hole. Roots are relatively shallow.

Established trees, those with a strong, healthy, root system do best in
full sun and most varieties will survive our mild frosts with minimal
damage but if the weatherman threatens a hard freeze, protect them. The
bark on avocados is sensitive to sun burn. A well foliaged tree is
adequate protection but exposed bark should be painted with white latex
paint even in the winter. Young, tender trees should be sheltered from both 
direct sun and frost. Filtered light is ideal. An exposure with full sun in 
the cool morning and some hot afternoon shade is also adequate. Remember 
that the tree thrives on light and will do its best with the most it can 
tolerate.

Browning leaf tips are usually the result of salt burn. Both soil and water 
in the Salt River Basin have about an 8.5 pH. The salt can't evaporate and 
the high concentration is toxic to the leaf cells. Dead tissue creeps 
further and farther up the leaves until they drop. The dead tissue can no 
longer produce carbohydrates through photosynthesis and the tree dies a slow 
agonizing death from starvation. Deep irrigation (flushing the root zone), 
mulching to prevent salt build-up from evaporation in the basin and beyond 
the drip zone with good drainage may keep salt levels to a tolerable limit.

----- Original Message ----- 
From: <pvsavini at yahoo.com>
To: <arid_gardener at Ag.arizona.edu>
Sent: Tuesday, November 27, 2007 2:26 PM
Subject: [Arid_gardener] Question from Home-Hort WWW page

> Pauline Savini
> 85201
> pvsavini at yahoo.com
>
> I would like to know how to plant and maintain an avocado tree here in 
> Maricopa County.
> I read that propogating from an avocado seed will produce a plant, but one 
> w/o fruit.  Is that true?  If so, where can I purchase an avocado 
> plant/tree?
>
>
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> Arizona 