Avocado Growing in the East Bay
compiled June 2011, by John Valenzuela, Cornucopia Food Forest Gardens
cornucopiafoodforests.wordpress.com
The name avocado derives from the Spanish aguacate, from the Aztec Nahuatl word ahuácatl (meaning
testicle, a reference to the shape of the fruit), known by the Aztecs as the fruit of fertility.
Introduced to California by seeds with Spanish Missionaries from Mexico about 1871. Popularized in the 20’s
and 30’s, it has became an important California export specialty crop. A very thirsty plant for Southern
California, it needs much water. There were even commercial avocado groves in the Los Altos Hills (South Bay)
50 years ago.
Early introductions (pre-1900) of avocado trees in our area included Los Gatos, Berkeley, Napa Soda Springs,
and Yountville. Largest trees in the Alameda and Contra Costa Counties are 2-3 ft in diameter and up to 40 feet
tall, and bear fruit regularly. Perhaps because of the large size, few newer trees have been planted.
Adaptability of Avocados to the East Bay:
Good Drainage, plant on hillside (see Microclimate, below) or mounds, for NO chance for winter water logging.
Mild climate needed
Winter Microclimate: Enjoys good cold air drainage on hillsides, evergreen winter protections above (Hardy
palms) that allow low winter sun angle to penetrate. Some varieties taking as low as 20 degrees F, frost
tolerances for each variety are listed below. Heavy winter winds can cause heavy fruit swing wildly and damage
the trees
Heat and Sun Enjoys a mild to warm summer climate 70-80 degrees F. Sun on bare branches can cause bark
damage, protect them with white wash or Bio-dynamic tree paste. Temps over 100F cause flower and fruit drop
and can damage leaves.
Shallow roots- Do not till underneath, need mulch (leave the leaves where they fall) and compost, add 3” of
wood chips or green waste, avoid excess manures which contain many salts. Let dry between frequent shallow
irrigations. Adequate irrigation is important for young trees.
Supplement quarterly fertilization with micro-nutrients (like soluble kelp) If mature tree has yellow leaves,
try more Nitrogen first, if leaves are smaller than usual and are mottled yellow, make zinc more available by
reducing pH, increase organic matter, and don’t over water.
Intolerant of salts (symptoms show as brown leaf edges), caution with greywater use. (West Indian types are
more tolerant, but are cold sensitive) Flush every month with rain water. 6- 10 drippers or sufficient sprinklers
Pollination with ‘A’ and ‘B’ types: Many recommend that "A" and "B" type avocados are needed, which X
cross pollinate each other (A= female morning + male afternoon, B= male morning, female afternoon). In
Northern California, cool weather allows the flowering to overlap, so avocados can often self-pollinate. While
partially self-fertile, they will benefit from cross-pollination with those A and B types, with bees and other
pollinators being very helpful.
Stacking/Shade tolerance Makes very dense shade, along with heavy mulch over shallow roots, limits root
crops or sun loving plants, within the drip line at least.
Pests Rats and Raccoons can consume the mature fruits, prune away any branches that provide a bridge to
other plants, trees or buildings, and wrap main stem with sheet metal. Mites can be a problem.
Diseases: Root rot main problem, do not over water, let dry between frequent shallow irrigation,
Propagation: Seeds are sprouted (Mexican types for cold resistance, or West Indian types for salt tolerance in
frost-free areas), grown until pencil size, then grafted or budded. Older trees can be cut back severely and topworked. Clonal rootstocks are propagated with etiolation of seedling shoots. Roots are brittle and fragile, use
root trainer containers, to avoid root circling. Productive older trees should be documented, propagated, and
distributed.
Page 1 of 4
Avocado Growing in the East Bay
compiled June 2011, by John Valenzuela, Cornucopia Food Forest Gardens
cornucopiafoodforests.wordpress.com
The main types of avocados: Persea americana: West Indian- most tropical, leathery skin, low with oil
content, Guatemalan- thicker sometimes granular skin, and Persea drymifolia: Mexican- anise scented leaves
used in cooking, thin (often edible) skinned, most cold hardy, and hybrids of West Indian X Guatemalan, and
and Mexican X Guatemalan types (the latter being some of the best).
Two sure bets for the Bay area would be ‘Mexicola’ and ‘Bacon’. Many others varieties are possible:
Notes on Varieties, with references at end
Mexicola (A)
Origin Coolidge, Pasadena, 1910. Mexican. Tree
tall and spreading, vigorous. Fruit small, 5 oz.,
round pyriform, skin paper-thin, purplish black,
waxy bloom. Flesh highest quality, seed very large.
Hardiest cv. known, seedlings useful as rootstocks
in far north. Recovers rapidly from freeze.
Defoliated at 20° F, trunk killed at 17° F. Season
September. (Fruit Facts)
'Mexicola' (Mex. originated about 1910 at
Pasadena, California; propagated about 1912);
very small; skin black; flesh of excellent flavor; seed
large. Season: Aug. to Oct. Grown only in home
gardens in California. Bears early and regularly;
very heat- and cold-resistant; much used as a
parent in California breeding programs. (J. Morton)
Mexicola Grande
Seedling selection of Mexicola. Mexican. Tree tall
and spreading similar to Mexicola. Fruit 15% - 25%
larger than Mexicola and somewhat rounder in
shape with better seed/flesh ratio. Skin paper-thin,
purple-black. High quality flesh with high oil
content. Hardy to about 18° F.
Duke (A)
Origin Bangor (Oroville), 1912. Tree vigorous,
open, resists wind. Fruit small, 12 oz., elongated
pyriform, waxy green, skin paper-thin. Flesh
excellent, oil 21%. Seeds commonly used for
rootstocks, resist root rot. Extraordinarily hardy,
recovers quickly from freeze, to 22° F. Season
October (Fruit Facts)
Duke (Mex., originated in California in 1912);
elongated; rather small 5 1\2 to 7 oz (150 200 g);
flesh of good quality, 14.5% oil. Season: Sept. to
Nov. in Calif.; late July or mid Aug. to mid-Sept. in
Israel. Tree is large, symmetrical and wind and
cold-resistant, and also highly resistant to root rot,
especially when grown from cuttings. It is a poor
bearer in some areas of California; has borne 168
lbs (78 kg) annually from the 6th to the 15th year in
Israel. (J. Morton)
Topa Topa (A)
Origin E.S. Thatcher, Ojai, 1912. Mexican. Tree
columnar, vigorous. Fruit handsome, elongated
pyriform, small to medium, 8 oz., smooth dark
purple with white waxy bloom. Skin paper-thin.
Flesh rather poor, oil 15%, seed elongated.
Seedlings commonly used for rootstocks. Hardy, for
far north. To 23° F.
Ganter (B)
Origin Albert Rideout, Whittier, 1905. Mexican. Tree
tall, spreading, open. Fruit small, to 8 oz., long
pyriform, skin paper-thin, pale waxy green. Flesh
good, oil 18%. Oldest avocado cv. in California.
Quite hardy, for Central Valley floor and far north.
To 23° F. Season October. (Fruit Facts)
'Ganter' (Mex., originated in 1905 in California;
introduced into Israel in 1943); small, about 5 1/2
oz (150 g); of good quality, 18% oil; seed small to
medium, usually loose. Season: Oct. to Dec. in
Calif.; second half of Sept. in Israel. Tree is small,
yields no more than 44 lbs (20 kg) per year. Poor
shipper. (J. Morton)
Bacon (B)
Origin James Bacon, Buena Park, 1954. Guat X
Mex.Hybrid. Tree broad, productive. Fruit small to
medium, to 12 oz., round-ovoid, smooth green.
Flesh only fair, almost colorless,seed cavity molds
rapidly. Hardy for Bay Area, Central Valley. To
25° F. Season December. (Fruit Facts)
'Bacon' Guat. X Mex. Hybrid, Quality of flesh
slightly better than 'Zutano'. Season: slightly later
then 'Zutano'. Tends to be affected with end spot,
an external blemish. This cultivar and 'Zutano' are
the only 2 reasonably productive of 60 cultivars
tried in Los Angeles and Orange Counties in
California. In 1957, top working of all the others to
these 2 cold hardy cultivars was strongly
recommended. 'Bacon' is a good choice fo9b0r
tropical American highlands about 5,200 ft (160 m).
(J. Morton)
Page 2 of 4
Avocado Growing in the East Bay
compiled June 2011, by John Valenzuela, Cornucopia Food Forest Gardens
cornucopiafoodforests.wordpress.com
Zutano (B)
Origin R.L. Ruitt, Fallbrook, 1926. Hybrid. Tree
columnar. Fruit small to medium, to 10 oz.
elongated smooth green, resembles Fuerte but
inferior, has fibers. Hardy for Bay Area, Central
Valley. To 25° F. Season November. (Fruit Facts)
'Zutano' (Mex. hybrid, originated in 1926 at
Fallbrook, California; registered in 1932); pear
shaped; medium-small, skin light green, very thin,
leathery; flesh watery, 15 to 22% oil; seed medium.
Season: Dec. and Jan. in California; Apr. and May
in Queensland where it is considered of poor
quality delicate to handle, and prone to disease
during ripening. Tree is a good bearer. Ranks
among 6 leading commercial cultivars in California,
being grown where it is too cold for 'Hass'. (J.
Morton)
The following tolerate less frost than those above:
Hass (A)
Origin Rudolph Hass, La Habra Heights, 1926.
Seedling of Lyon. Guatemalan. Tree rather open,
not tall. Fruit medium, to 12 oz., pyriform, skin thick,
pebbled, coppery purple. Flesh good, oil 19%, seed
fairly small. Currently the standard of the industry.
To 26° F. Season July. (Fruit Facts)
'Hass' (Guat. X Mex. hybrid, seed planted at La
Habra Heights, Calif.; registered in 1932); pear
shaped to ovoid; of medium size; has a tendency to
be undersized except in New Zealand; skin tough,
leathery, dark-purple or nearly black when ripe;
pebbled; fairly thin; flesh of good flavor, 18 to 22%
oil, generally; up to 35% in Queensland; seed
small. Season: begins in mid-Mar. in California;
Nov. to Jan. in Queensland; mid-Nov. to Mar. in
New Zealand; Aug. and Sept. in New South Wales.
Formerly accounted for 20% of California avocados
shipped; now is the leading cultivar (70% of the
crop in 1984). Tree bears better then 'Nabal' in cool
areas of California, but grows tall and requires
topping. This is the leading cultivar in New Zealand,
representing 50% of all commercial plantings; 25%
in Queensland. It is second in importance to
'Fuerte' in Chile. (J. Morton)
Fuerte (B)
Origin Atlixco, Mexico, intro. Carl Schmidt, 1911.
Hybrid. Tree open, spreading, tall. Fruit large to
very large, 16 oz., elongated pyriform, skin dark
green with numerous small raised pale spots, waxy
bloom, skin thin. Flesh good, oil 18%, seed
medium. Formerly standard cv. of California
industry. Tends to bear in alternate years,
unproductive near coast or in north. To 26° F.
Season December. (Fruit Facts)
'Fuerte' (a natural Guat. X Mex. hybrid originated at
Atlixco, Mexico; introduced into California in 1911);
pear shaped; small to medium or a little larger; skin
slightly rough to rough, with many small yellow
dots, thin, not adherent to flesh; flesh green near
skin, 12 to 17% oil; seed small, tight. Season Jan.
to Aug. in southern California; Dec. to Feb. in
Israel; Apr. and May in Queensland, and New
South Wales; mid-Aug. to Oct. in New Zealand.
Tree is broad, very productive, but tends to bear
biennially. Subject to scab and anthracnose in
Florida. Formerly very popular in California (61 % of
all avocados shipped); now second to 'Hass'
because of a trend to summer instead of winter
production and marketing that began in 1972. It is
the leading cultivar in Chile where it bears more
dependably than in California. It is a very erratic
bearer in Israel. Represents 42% of all Australian
plantings. Has long been the leading avocado on
the European market. (J. Morton)
Fuerte. — Form pyriform (not necked) to oblong;
size below medium to above medium, weight
10 to 16 ounces, length 4 to 41/2 inches, greatest
breadth 21/2 to 2⅞inches; base pointed; the
stem inserted obliquely in a small shallow cavity;
apex obliquely flattened, depressed around the
stigmatic point; surface pebbled, sometimes slightly
wrinkled around the stem, dull green, with
numerous small yellow dots; skin about 1/24 inch
thick, separating readily from the flesh, pliable
and leathery in texture; flesh rich cream yellow in
color, greenish near the skin, of smooth buttery
texture, and very rich flavor; quality excellent; seed
small, tight in cavity, seed-coats closely
surrounding cotyledons. Season January to August
in southern California. Originated at Atlixco, state of
Puebla, Mexico; first propagated in 1911, in which
year it was introduced into California. An unusual
variety, apparently a hybrid between the
Guatemalan race of Persea Americana and the
Mexican race (P. drymifolia). It is characterized by
great vigor of growth, hardiness, good
productiveness, and a long season of ripening
differing from that of nearly all Guatemalan and
Mexican varieties. The fruit contains as much as 30
per cent of fat, and is of very pleasant flavor.
(Popenoe)
Queen (B)
Origin Antigua, Guatemala, intro. by E.E. Knight,
1914. Guatemalan. Tree broad. Fruit exceptionally
large, to 24 oz., elongated, purple, flesh excellent,
oil 13%. Fairly hardy for large cv., worth trying in
Bay Area. To 26° F. Season August.
Page 3 of 4
Avocado Growing in the East Bay
compiled June 2011, by John Valenzuela, Cornucopia Food Forest Gardens
cornucopiafoodforests.wordpress.com
Ryan (B)
Origin Albert Rideout, Whittier, 1927. Hybrid. Tree
low, spreading. Fruit medium, to 14 oz., elongated,
otherwise resembles Hass, skin thick, pebbled,
purple. Flesh good, oil 25%. For Inland Empire, Bay
Area. To 26° F Season August.
Other types found in Julia Morton’s ‘Fruits of Warm
Climates’:
Guatemalan types:
Macarthur' (A) (originated in 1922 at Monrovia,
California); pear-shaped; large; skin thin, pliable;
flesh has sweet, nutty but watery flavor, contains 13
to 16.7% oil; seed medium to large. Season: Aug.
to Nov. in California; Aug. and Sept. in Queensland
where it is rated as of poor quality. It is one of the 6
leading commercial cultivars in California, where it
is very cold-hardy.
'Pinkerton' (A) (seedling, probably of 'Rincon', found
on Pinkerton ranch in Ventura Co., California, in
1970; patented); early crop roundish; later, pear
shaped with neck; of medium size, 8 to 14 oz (227397 g); skin medium-leathery, pliable; flesh thick,
up to 10% more than in 'Hass' or 'Fuerte'; smooth
textured, of good flavor, high in oil, rated as of good
quality but inferior to 'Hass' and 'Fuerte'; tends to
darken in the latter part of the season; seed small,
separates readily from the flesh with the coat
adhering to the seed. Season: first crop, Oct. or
Nov., 2nd crop, Dec. or Jan. Fruit ships well and
has good shelf life, but the neck is a disadvantage
on the fresh fruit market; accordingly, the lateseason fruits are sent to processing plants. The
tree is of low, spreading habit; bears early and
heavily; is as cold-sensitive as 'Hass'. About 1200
acres (486 ha) in California in 1984.
'Reed' (A) (originated about 1948 on Reed property
in Carlsbad, California, as a seedling, possibly of a
'Anaheim' X 'Nabal' hybrid; patented in 1960; patent
now expired); round; medium to large, 8 to 18 oz
(227-510 g); skin slightly rough, medium-thick,
pliable; flesh cream-colored with rich, faintly nutty
flavor; doesn't darken when cut; rated as excellent
quality; seed small to medium, tight; coat adheres
to seed. Season:July to Oct. in California; late Feb.
to Apr. in New Zealand where it is one of the most
promising cultivars. Tree erect, can be spaced 15 x
15 ft (4.6x4.6 m); bears early and regularly; about
as cold-sensitive as 'Hass'. In 1984, about 1,000
acres (405 ha) in California.
GUATEMALAN X MEXICAN hybrid
'Sharwil' (originated in Australia); similar to 'Fuerte'
in shape but a little more oval; of medium size, skin
rather rough, fairly thin; flesh rich in flavor, of high
quality, 15 to 26% oil. Season: May and June in
New South Wales and Queensland. Tree bears
regularly but not heavily. Represents 18 to 20 % of
all avocados in New South Wales and Queensland.
Disease-free during ripening.
References:
CRFG Fruit Facts
http://crfg.org/pubs/ff/avocado.html
Julia Morton, Fruits of Warm Climates
http://www.hort.purdue.edu/newcrop/morton/avoca
do_ars.html
Gary S. Bender, Ph.D. UCCE San Diego Farm
Advisor, Avocado Production in Home Gardens
http://www.mastergardenerssandiego.org/download
s/Avocado%20Production%20in%20Home%20Gar
dens.pdf
WILSON POPENOE, Agricultural Explorer, United
States Department Of Agriculture
MANUAL OF TROPICAL AND SUBTROPICAL
FRUITS EXCLUDING THE BANANA,
COCONUT, PINEAPPLE, CITRUS FRUITS,
OLIVE, AND FIG, THE MACMILLAN COMPANY,
1934 (Originally published 1920), NEW YORK,
(Avocado Chapter, pages 9-78)
http://books.google.com/books?id=kTAaAAAAYAA
J&pg=PA9&lpg=PA9&dq=manual+of+subtropical+fr
uits+avocados&source=bl&ots=Xo9VNn5P0w&sig=
BNj9VmQNZUyOAiiRxBdgzb1LklM&hl=en&ei=BqY
ETvXsC4iftwf4tPngDQ&sa=X&oi=book_result&ct=r
esult&resnum=2&ved=0CB8Q6AEwAQ#v=onepag
e&q&f=false
Prof. I. J. Condit, College Of Agriculture, Berkeley,
THE AVOCADO IN CENTRAL AND NORTHERN
CALIFORNIA
http://www.avocadosource.com/CAS_Yearbooks/C
AS_03_1917/CAS_1917_PG_35-39.pdf
Pam Pierce’s Blog, http://www.sfgate.com/cgibin/article.cgi?f=/c/a/2011/05/12/HOOM1JDCIB.DT
L#ixzz1QCUtDpeJ
Epicenter Avocado Trees & Fruit
Specializing in Rare & Exceptional Avocado Trees
http://www.epicenteravocados.com/
Page 4 of 4