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McHargue, L.T. 1996. Macadamia production in southern California. p. 458-462. In: J. Janick (ed.), Progress in new crops. ASHS Press, Arlington, VA.

Macadamia Production in Southern California

Lawrence T. McHargue

    1. Cultivars
    2. Cultivation Practices
    3. Harvesting and Handling
    4. Publicity and Marketing

The genus Macadamia, a member of the Proteaceae, is native to eastern Australia. Two Macadamia species produce edible seeds (Macadamia integrifolia Maiden & Betche and M. tetraphylla L.A.S. Johnson). Macadamia integrifolia is native to the rainforests of southeastern Queensland, and M. tetraphylla occurs farther south in the rainforests of New South Wales. Macadamia integrifolia is more tolerant of temperature extremes than M. tetraphylla. The flowers are borne in pendulous racemes. Flower color ranges from white to cream in M. integrifolia and cream to beige in M. tetraphylla. Hybrid flower colors range from cream to pink. Both species are insect pollinated. Bee pollination is normal in California.

William Purvis introduced the first macadamias into Hawaii in 1881, though the major development of the Hawaiian macadamia industry occurred after 1930 (Cooper 1988). At one time it produced 90% of the world's supply. Annual macadamia nut production ranged from 21,400 to 22,550 t during the five year period of 1989 to 1994. Approximately 7,100-7,500 ha of macadamia plantings were harvested during the same period (USDA 1993; Rowley et al. 1994). Most Hawaiian macadamia production is from Macadamia integrifolia derived cultivars. The University of Hawaii and Hawaiian macadamia growers have actively engaged in research in macadamia cultivation and in the selection of improved macadamia cultivars. The Hawaiian industry has been diligent and aggressive in marketing and sales.

Hawaiian dominance of world production is currently being challenged. Australian plantings and production have expanded dramatically during the past 30 years. There are currently 20,000 ha devoted to macadamia plantings. One third of the area planted to macadamias is mature, another one third is in the early bearing stage, and another third is not yet bearing. Approximately 30% of world production now comes from Australia, and the Australian Macadamia Society projects that Australia will double its percentage of world production within five years (Stapleton 1995). Australian production increased from 4,400 t in 1987 to 21,000 t in 1995. Commercial plantings in Australia were initially based on Macadamia integrifolia cultivars developed in Hawaii, but newer selections from Australia are now coming into production. Australia currently has the world's largest macadamia research and selection program, and their industry is actively seeking new and expanded markets.

Macadamia orchards have also been established in Central America, Brazil, Kenya, Indonesia, Taiwan, and southern Africa (Arpaia 1994). Processed nuts grown in Guatemala are being marketed in the United States by one of the larger Hawaiian macadamia producers and processors. However the total world production of macadamia nuts is quite small, and it constitutes less than 0.5% of the total world nut sales (Stapleton 1995).

Macadamia seeds were first brought to California from Australia in 1879 (Ferguson and Arpaia 1990). A number of seedlings were successfully grown in southern California subsequent to that introduction, though Wickson (1910) made no reference to macadamias. There was some interest in Pasadena and Whittier in the 1920s, and a few relic trees from that time remained for decades. I examined one of the early seedling trees and its nuts in the 1950s. However, little interest was shown in commercial macadamia cultivation until the 1950s when several nurserymen began to promote macadamia growing and production. One of these was Cliff Tanner who propagated a number of tropical and subtropical fruits and nuts in addition to the macadamia. Another was Colonel Wells Miller. Macadamia enthusiasts formed the California Macadamia Society in 1953. The Gold Crown Macadamia Association has marketed California grown macadamias for its member growers for over two decades. Macadamia production has not attained the status of an economically important crop in California, despite efforts made by individuals to develop production. Most of the population of the region appears to be unaware that there is any commercial macadamia production in Southern California. Hawaiian and Central American produced nuts dominate the southern California market despite the fact that substantial macadamia production is possible there.

Macadamia trees grow successfully at a number of points in California. Macadamia climatic requirements are similar to Mexican or Guatemalan races of the avocado. Macadamia trees are intolerant of heavy frost. Frost damage begins to occur at -2.8°C (27°F), especially if the period of low temperatures lasts for several hours. Macadamia trees are also intolerant of prolonged periods of high temperatures and low humidity, and this precludes commercial macadamia production in the thermal belts of the San Joaquin Valley or in relatively frost-areas of the Sonoran Desert. Commercial production of macadamias is therefore located in San Diego, Ventura, and Santa Barbara Counties. Climatic conditions are also suitable in Orange and Los Angeles Counties, but those counties are now so intensively urbanized that there is little or no potential land area left for macadamia cultivation. Neither production volumes nor the land area devoted to macadamia production in California are available. There were an estimated 600-800 ha of macadamia plantings in 1988 (Cooper 1988). Long (1988) estimated that there were about 400 ha in San Diego County. It appears that the area devoted to macadamia production has probably declined, but there are no accurate figures to indicate how much. Many of the producing trees have been planted to replace avocado trees that have been infected by avocado root rot (Phytophthora cinnamomi). Accurate estimates on the land area occupied by macadamia trees that are scattered through avocado groves are not available. Other producing trees have been planted on small plots of land around homes or on the edges of avocado or citrus groves. No one has determined the extent of area planted in macadamias in this manner, yet there is commercial production from these plantings.


Most cultivars grown in California are derived from Macadamia tetraphylla or M. tetraphylla x integrifolia hybrids (Ferguson and Arpaia 1990). Macadamia tetraphylla is less tolerant of temperature extremes than M. integrifolia. Its requirement for very even temperatures (7deg. to 26deg.C) limits its productivity and geographic range. Hybrid cultivars have generally been more productive in California than those derived from M. integrifolia, though the 'James' is an exception. Macadamia integrifolia cultivars usually bloom in mid-winter in California. Flower production and pollination are low in cold years resulting in poor yields. Hybrid cultivars usually bloom during the spring when the weather is more moderate and pollination is more certain. They are more tolerant of temperature extremes than Macadamia tetraphylla, and are well suited to the coastal climate of southern California (Cooper 1988).

The flavor of cultivars derived from the two Macadamia species differs perceptibly. Macadamia tetraphylla cultivars produce nuts with a high carbohydrate content, sweeter flavor, and a lower oil content than those from M. integrifolia, though they are more difficult to process and stabilize for shipping and storage. The high oil content of M. integrifolia gives it an advantage over M. tetraphylla for roasting and salting (Stapleton 1995). Subtle but real differences in flavor between the two groups of cultivars offer a particular niche to California growers, for macadamia production in Hawaii and Australia is primarily from M. integrifolia cultivars. The sweetness of fresh macadamia nuts from the M. tetraphylla x integrifolia hybrids usually grown in California makes it unnecessary to salt them, though a few growers roast and salt nuts in the same manner that Hawaiian or Central American producers do. The flavor of California produced macadamias is excellent, and it is a major advantage for growers. The sweetness of California grown macadamias is well suited for various confections. The flavors of candies and other confections made from California nuts are somewhat different from similar products from Hawaii. Frieda's Inc. of Los Alamitos, California buys all of the macadamia nuts included in their products from California sources. Most of the sales volume of California macadamias is repeat business.

Present and potential macadamia production areas in California are both scenic and readily accessible to the large urban populations of Southern California. Direct marketing can be done by growers. People can easily visit macadamia orchards and purchase nuts directly from a grower as they do with a number of other fruits and nuts. Macadamias are popularly perceived as an exotic specialty crop. They therefore have a certain built-in appeal to some segments of the southern California population.

The proximity of production and markets obviate the need to package and preserve California grown nut meats in the same manner as Hawaiian and Central American producers do for their sales to distant markets. High temperatures or prolonged roasting alters the flavor of the nuts. There is a market for both fresh and packaged nuts, and California growers have an advantage in marketing the former, especially in California and the Southwest. The proximity of production and marketing also permits California growers to market unshelled macadamia nuts to the public more economically than growers located in distant regions. The hardness of macadamia shells requires specially designed and built nutcrackers. There is a certain risk involved in unshelled nut sales, for some nuts are always defective. The purchase of shelled nuts permits the processor to eliminate defective nuts and the customer to observe the quality of the nuts being purchased. The unit price of the nut meats is thus similar in shelled and unshelled nuts.

Macadamia trees in California suffer from fewer diseases and pests than most other crops. They are not particularly susceptible to the oak wilt fungus that has devastated many avocado orchards in southern California.


Land is expensive and will become increasingly so as urbanization occurs in those areas best suited for macadamia cultivation. Agricultural land area is being lost due to rapid urbanization, and the average size of all land holdings, including agricultural acreage, is declining. The cost of the labor needed to produce macadamia nuts is higher in California than in other areas. Productivity in yields and in return must therefore be quite high to compete successfully with production in other areas of the world. The cost of irrigation water has risen steadily, and it can be expected to increase even more with increasing competition between urban and rural areas of California for finite supplies.

The high cost of macadamia production dictates high retail prices. Current retail macadamia prices are $6.60 to 8.80/kg($3 to 4/lb) for nuts in the shell, and $30.80/kg ($14.00/lb) for shelled nuts.


There are four principal areas of need if macadamia production is to expand and be profitable in California: improved cultivars, continued progress in cultivation practices, improvements in nut harvesting and handling, and major improvements in publicity and marketing. It is my opinion that there is a potential for increased output and profitability for macadamia production in California. However, that potential will not be realized without a major expenditure of time and effort on the part of those involved in macadamia production and marketing.


Growers and nurserymen must make efforts to improve the quality of the cultivars being grown in California (Cooper 1992). Efforts to select for better and higher yielding cultivars have not been adequate, and there has been no comprehensive program to develop new cultivars (Ferguson and Arpaia 1990). California growers have strong and divergent opinions regarding the desirability of different cultivars. Plant breeders and growers must explore as much genetic diversity as possible from which to select and recombine favorable traits through plant breeding. New and existing cultivars from other areas of the world should be tested in our climate. Macadamia growers and existing nurseries need to make efforts to improve macadamias and cooperate with a state or federal program. The experiment stations of the University of California should initiate a program of macadamia improvement because this is a long term program that requires public support. Louise Ferguson, of the University of California, Davis and the experiment station at Parlier, stated in a telephone conversation on 24 Jan. 1996, that financial support from the macadamia industry is essential for the establishment of such a program.

More information is needed regarding rootstocks because soils in California are highly variable. Clay soils slow the time needed to reach maturity, though the slower growth of the root system results in trees having firmer anchorage. Selections should also be made for cold hardiness. Recently 'Cynthia' has been used as a rootstock for cold resistance (Cooper 1992).

Cultivation Practices

Continued work needs to be done in cultivation practices and methods of propagation. The Mediterranean climate and soils of southern California differ significantly from those of other macadamia producing areas. These differences are reflected in the dominance of Macadamia tetraphylla x integrifolia hybrid cultivars in California. A research program is needed to ascertain optimum and the most economical cultivation practices.

Harvesting and Handling

Opinions differ regarding the best methods of harvesting. Some growers wait until the nuts drop from the tree while others harvest the nuts from the tree itself. Studies should be undertaken to ascertain differences between harvesting methods in nut quality and efficiency.

Technology used in other crops has been applied to macadamia handling and processing, and some of the machinery being used has been developed by individual growers. Mechanized processing equipment is available from firms, such as the R.P. Barton Co. of Escalon, California; Shaw Macadamia of Gooding, Idaho; or Keiser Manufacturing Co. of Sequin, Texas. However most their equipment is designed to handle large quantities of product, and the equipment is costly. There is a largely unfilled need for small scale harvesting and handling equipment. More and innovative thought is needed to increase efficiency in harvesting, processing, and handling the product.

Publicity and Marketing

There is an acute need for more effective marketing and publicity regarding macadamia production in California. California growers should not simply sell their macadamia crop to brokers who sell the nuts in a world market dominated by cheaper nuts from areas having lower production costs. California produced macadamia nuts will inevitably be unprofitable, even if nut wholesalers would be willing pay a somewhat higher price for them. Wholesaler brokers alone will not and cannot pay a sufficiently high price to bring prosperity to the macadamia industry. Teeter (1993) presented a gloomy analysis of the costs of macadamia production in southern California.

California macadamia nuts cannot compete against other, cheaper nuts if they are marketed and consumed in exactly the same manner as nuts from Central America, Australia, and Hawaii. California growers and marketers must emphasize the different flavors and texture of their product as a niche market if they are to build a successful industry. Growers should emphasize the different flavor of freshly roasted, unsalted nuts. Their product must be perceived as being equal to and somewhat different from the best macadamia nuts grown in other areas, and that perception must be based on reality. The economics of production demand that California grown nuts sell at higher prices than nuts grown in other areas.

Macadamia growers must play the dominant role in marketing and publicizing their crop. They produce a specialty crop that is rightly considered to be a gourmet food. Growers should sell as many nuts and macadamia products as possible themselves. More direct marketing and dealing with fewer handlers between grower and producer will bring higher prices to the grower and more affordable prices for the consumer. Several growers sell nuts and confections directly to the public. More direct marketing efforts are needed. Growers should cater to tourism as the date industry has done in the Coachella Valley or the apple growers have done in Oak Glen. More publicity is needed to acquaint the public with the existence of macadamia growing and macadamia products in California.

Individual outlets for nuts and nut products will probably not be sufficient to sell all the crop, especially if production increases substantially. Growers should deal individually or collectively with specialty food stores such as Farmers Market, Bristol Farms, Trader Joe's, and others who already sell processed nuts from other areas of the world to an affluent and specialty oriented clientele. These firms sell specialty candies and baked goods, and these would be possible outlets for nuts and nut parts. The Gold Crown cooperative currently sells to Frieda's Inc. of Los Alamitos California. Similar marketing arrangements should be sought out by growers. Those involved in macadamia production and marketing should also make efforts to have macadamia nuts or products incorporated into the style of cooking known as "California cuisine."


California macadamia growers have both major advantages and disadvantages that confront their industry. They must engage in a major, collective effort if the industry is to expand and be profitable. Decisive leadership and consensus regarding goals for the industry are needed. Those in the macadamia industry must expand their efforts in promotion and marketing. More studies and quantitative data regarding production and marketing are necessary. Thompson Cooper (Internet: is currently working to establish an on-line data base for the industry. A long term University of California research program should be undertaken. More knowledge of cultivation practices, better yielding cultivars, and increased marketing efforts are all prerequisites for increased macadamia production and profitability in California.


Last update June 23, 1997 aw