Like a Day Without Sunshine: The Past and Future of Florida Citrus

Oranges are so closely associated with the State of Florida that it seems like they’ve always grown here in abundance. But in fact, citrus trees are not native to Florida, and the state’s $9 billion a year citrus industry is the product of a 120-year struggle against the elements, diseases, and pests—a struggle whose outcome is far from certain today. Keeping citrus groves thriving and profitable against all odds has been a major task for researchers and extension agents from the University of Florida since 1889.

A Land of Wild Groves

Citrus came to Florida with the expeditions of Columbus and Ponce De Leon. No one’s quite sure when orange trees were first planted, but by 1579, travelers were commenting on citrus growing in the town of St. Augustine. European explorers and native Americans must have cultivated oranges trees throughout the state; in 1761, writer William Bartram described wild orange groves along the St. Johns River, and an enormous grove outside New Smyrna nearly half a mile wide and stretching north about forty miles. “All this ridge,” wrote Bartram, “was then one entire orange grove, with live oaks, magnolias, palms, red bays and others.”

Grapefruit, another important citrus fruit, was first planted by Spanish nobleman Don Phillippe on his estate in the area around Pinellas County in 1809. A little more than a decade later, Spain ceded Florida to the United States, and a new, more enterprising breed of pioneers began moving into the state. Settlers near St. Augustine began planting groves and harvesting oranges, which they shipped up the St. Johns River to markets in Charleston, Baltimore and New York. One of the most famous early citrus groves in Florida was established by Douglass Dummitt on Merritt Island in the late 1820s. Dummitt developed a new propagation technique by cutting wild sour orange trees down to a few feet from the ground and grafting the buds of sweet orange trees onto the stumps. Known as ‘top working,’ this technique shaved years off the growing process and produced a hardy tree that yielded sweet oranges in high demand by the northern markets. By the 1860s, Dummitt had over 2,000 trees in his groves, each yielding about 10-20 boxes of oranges.

Scenes among the orange growers, 1883. Source: Florida Memory Project

Orange Fever

Railways began reaching into Florida after the Civil War, creating a boom in citrus production. Pamphlets and broadsides sold the state as an earthly paradise; using Dummitt’s top-working techniques, yeoman farmers could purchase acres of groveland, quickly make back their investments with minimal effort, and bask in the sunshine of their growing fortunes. At the same time, horticultural science was reaching citrus growers with new techniques for increasing their yields and protecting their groves from diseases and pests. The Florida Agricultural Experiment Station was established at the University of Florida at Plant City in 1889 and the USDA’s Subtropical Research Laboratory in Eustice was established in 1892. By that time, Florida was producing over 5 million boxes of oranges annually, making it the state’s largest economic product by a wide margin. Between 1870 and 1890, the state’s population more than doubled to 391,000 people and new cities such as Orlando and Lakeland were popping up seemingly overnight along the Orange Belt that stretched from Jacksonville to Tampa. Florida’s economy was expanding and rising like an orange-colored balloon.

Postcard from the late 1890s. Source: Florida Memory Project

The Great Freeze

Then, between December 1894 and February 1895, two great freezes effectively destroyed the Florida citrus industry. As far south as Orlando, temperatures dropped to 18 degrees F on successive nights. Branches froze, tree barks split, fruit burst and fell to the ground. Citrus production that winter fell from a high of 6 million to just 50,000 boxes, and property values in groves dropped from $1,000 per acre to $10 per acre.

Freeze damage in a grove in Bartow, FL 1896. Source: Florida Memory Project

The few groves that managed to weather the freeze became legendary. One of them was Captain Dummitt’s grove on Merritt Island, making Indian River citrus famous for its cold-hardiness. Another survivor was the small town of Keystone City in Polk County, which was renamed Frostproof after the Great Freeze.


In a special post-mortem report on the freeze, the Florida Agricultural Experiment Station encouraged growers to persevere: “Will it pay to restore groves?…Could you look back some twenty years or more and see the hardy pioneer enduring his hardships in his rough surroundings and compare the scene with the beautiful homes now scattered all over the land, filled with cultivated and refined people, your answer would be: ‘Those men did better than they knew’…To restore these groves will be far less labor and expense than the pioneer undertook. Surely it will pay to restore them.” One of the co-authors of the report, P. H. Rolfs, would go on to become the director of the Florida Agricultural Extension Service when it was established in 1915.

Machinery, plow, horses, crops, tilling, farm. Source: Smather's Archives.
A citrus grower plows his grove, 1915. Source: Smathers Collection

Slowly, over the next two decades, Florida citrus returned to its pre-freeze state of health. Growers who hadn’t left for California or turned to other crops moved their operations south. With greater concerns about the health of their groves, growers turned to extension agents and citriculturists from the Agricultural Experiment Station for help. Some growers even donated land to the station so that they could conduct experiments on fertilizers, pest control and frost protection. In 1917, growers in Polk County raised $14,000 to purchase land for a new research center dedicated to Citrus. The Citrus Experiment Station (now called the UF/IFAS Citrus Research and Education Center) opened at Lake Alfred in 1919.

Soil Laboratory at UF's Lake Alfred Citrus Station 1944.
Soil Laboratory at the Citrus Experiment Station in Lake Alfred, ca. 1920s

Citrus Canker

By then there was another threat to Florida citrus culture. Citrus Canker, a bacterial disease that causes corky lesions to form on fruit, was first discovered in Jefferson County in 1912 and within two years had been found in trees throughout the state. Research by the USDA and the experiment station concluded that citrus canker bacteria could lie dormant for years, was highly contagious, and could only be controlled by burning infected trees on the spot. While citrus canker didn’t affect the taste of citrus, it left the fruit scarred and impossible to sell. Fearing another cataclysm to Florida’s citrus industry, growers influenced the state legislature in 1915 to form the State Plant Board, which immediately pursued an aggressive eradication program. The plant board trained extension agents and growers to inspect, diagnose, quarantine and destroy infected plants. Plant board inspectors did not fool around: they were required to take eye tests and wear special outer clothes and head coverings that would be washed before leaving the quarantine zone. Within a year of beginning the program, the number of infected properties dropped sharply, but the program continued to inspect and quarantine trees until the disease was declared eradicated in 1927. In all, 250,000 grove trees and 3 million nursery trees in 26 counties were destroyed, and $2.5 million (equivalent to $28 million today) in state and private funds were spent eradicating citrus canker.

Plant board inspector Ed Wartman prepares to enter a grove, 1926. Source: Smathers Collection

Despite the success of the eradication program, there have been outbreaks of citrus canker in 1986-1994 and from 1995 until the USDA abandoned eradication efforts as infeasible in 2006.

Mediterranean Fruit Fly

In 1929, just as citrus canker was under control, an outbreak of Mediterranean fruit fly resulted in another emergency eradication program. Almost all extension agents in affected counties were taken off their regular duties to organize clean-up crews to get rid of infected fruit or carry out educational work about eradicating the fruit fly. Although it was an 18-month disruption of their usual Extension work, it proved that agents were committed to saving Florida’s citrus and could be relied on in an emergency.

Pay scale for grove workers, ca. 1930s. Source: Florida Memory Project

WWII and Frozen Concentrate

During World War II, nutritionists in the War Department became concerned that GIs weren’t getting enough Vitamin C in their rations. From 1942-1945, the federal government bought most of the Florida orange crop, and challenged the state’s citrus commission to develop a concentrated citrus juice that could be shipped to GIs overseas. Although canned orange juice had been on the market since least 1917, it had little of the taste or nutritional value of fresh oranges. Experiments with powdered orange juice and lemonade were even more unsatisfactory (although they did eventually lead to Tang). Beginning in 1943, researchers from the Citrus Experiment Station pursued their own version of the Manhattan Project: perfecting orange juice as a freezable concentrate. Years of experimentation paid off, but as fate would have it, they filed their patent application on August 7, 1945, just one day after the bombing of Hiroshima.

Demonstration of orange juice concentrate at the Citrus Experiment Station, 1946. Source: Citrus Research and Education Center

Just Add Water

With the war over, the government quit buying oranges and growers were left with massive surpluses and plunging prices. The effect on the industry was as great as any freeze or pest infestation—many growers contemplated leaving the business or switching to avacados. Fortunately, the patent for frozen concentrate soon reached the market and the Florida Citrus Commission began an ambitious marketing campaign for frozen orange juice. By 1948, celebrities such as Bing Crosby and Arthur Godfrey were crooning about the delicious convenience of “fresh squeezed” Florida orange juice, and consumers responded enthusiastically. If you couldn’t live in Florida, you could always get a taste of the Sunshine State right from your supermarket’s frozen food case.

The success of Frozen concentrate orange juice, or FCOJ, literally transformed the Florida citrus industry. Growers began shifting their focus from large and attractive fresh market varieties to smaller, juicier varieties such as Hamlin and Valencia. A secondary industry sprang up for processing and canning orange pulp—6 processing plants opened in Florida in 1948 alone. Annual production jumped from 46 million boxes during the war years to more than 78 million boxes by 1952. The public demand for Florida citrus created a new real estate boom for grove country, so much so that Extension began publishing brochures warning inexperienced speculators about what they were getting into.

Trucks offloading oranges at the Minute Maid processing plant, 1950s.

The Florida Sunshine Tree

While Florida’s citrus culture was enjoying a renaissance, it was a much more complicated field than it had been in the 1880s. There were new pesticides on the market and more stringent regulations to go with them. There were rising production costs and market fluctuations, competition from California and Brazil, and disputes over land and water use with Florida’s growing aerospace industry, tourist attractions and urban centers. To help growers navigate this new environment, in 1947 Fred Lawrence was appointed Extension Citriculturist. A former citrus grower whose family lost their grove in the Mediterranean Fruit Fly outbreak of the 20s, Lawrence assembled a team of plant pathologists, horticulturists and economists to work closely with the industry, the experiment station and growers to develop a long term plan for Florida citrus. During the next 20 years, Extension helped organize the Florida Citrus Mutual to stabilize prices and trade practices; it held annual Citrus Institutes, short courses and training programs to keep growers and agents aware of the latest developments in citrus culture; it established a budwood certification program for nurseries to help reduce the spread of diseases; it lowered production costs by promoting minimal cultivation and irrigation; it advised growers on pesticide regulations and encouraged the use of biological control of insect pests; it promoted the use of cover crops to help fertilize soils, and much more.

Florida citrus has faced many setbacks since World War II–devastating freezes in the 1960s and 1980s, outbreaks of fungal infections such as Greasy Spot and Alternia Brown Spot, and infestations of crop destroying insects and nematodes. Throughout the post-war years, the close relationship between UF/IFAS Research and Extension and citrus growers has helped to weather these storms to make citrus the $9 billion industry it is today. However, in the past ten years a new threat has swept through Florida citrus, and it’s proven to be the most dangerous in the state’s history.

Like a Day without Sunshine—Greening Hits Florida

Warning signs of the latest and most serious threat to Florida’s citrus first appeared in Dade County in April of 1998, when Asian citrus psyllid, a tiny insect no larger than the head of a pin, was discovered on dooryard citrus plants. The psyllid had been known as a vector for the bacterium that caused huanglongbing, or citrus greening, which had been devastating citrus groves around the world since 1919. Entomologists tried to enact an eradication program for the psyllid, but it was too late—by 2000, it had already spread to 31 counties in Florida. Five years later, scientists’ worst fears were confirmed when the first case of greening was reported in Miami-Dade County.

Asian citrus psyllid, Diaphorina citri, highly magnified. UF/IFAS photo
Huanglongbing (HLB), or citrus greening disease, results in undersized, lopsided fruit that drops before maturity. UF/IFAS photo

The Asian citrus psyllid transmits the greening bacteria to trees when it sucks on leaf sap. Spreading throughout the phloem, the disease starves the tree of nutrients, damaging its roots and producing green, misshapen and bitter tasting fruit that drops unripe from the tree, unsuitable as fresh fruit or for juice. Usually, by the time greening is diagnosed in a grove, it’s too late to save it–most infected trees die within a few years. Since 2005, greening has spread to every citrus producing county in Florida, causing $3.63 billion in lost revenues and the loss of over 6,600 jobs.

Researchers at UF/IFAS have been working feverishly to combat the disease from every possible direction, from controlling the Asian citrus psyllid to developing disease resistant varieties of citrus. Researchers are even reaching back to citrus’ ancestral roots in Southeast Asia, trying to map the genomes of the two original species in search of disease-resistant genes. UF/IFAS extension agents have been passing this research on to growers, as well as helping them diagnose and contain the spread of citrus greening in their groves. Extension economists have been calling attention to the dire threat greening poses to Florida’s citrus culture and economy, which has resulted in greater public awareness and financial support for research that may soon find a cure for the disease.

Michael Rogers (left), Tim Spann and Ron Brlansky examine citrus trees for symptoms of citrus greening and the presence of the Asian citrus psyllid that transmits the pathogen, 2008. UF/IFAS photo

The hope of all this work is that someday, citrus greening will join the list of threats that growers were able to overcome with help from UF/IFAS researchers and extension agents, and that Florida will continue be the orange state for generations to come.


Florida Citrus Hall of Fame. n.d. Fred Lawrence.

Florida Cooperative Extension. 1929 Annual Report. Gainesville: University of Florida.

Florida Cooperative Extension. 1948 Annual Report. Gainesville: University of Florida.

Florida Memory. n.d. Bittersweet: The Rise and Fall of the Citrus Industry in Florida.

Hamilton, A. 2009. Squeezed: What You Don’t Know About Orange Juice. New Haven: Yale University Press.

Matthews, J.O. 1876. A New Enterprise! The Florida Orange Grove Company. Jacksonville, FL: Sun Printing Office

Moremen, M.S. 1896. Present Condition and Treatment of Orange Groves. Bulletin No. 88. Lake City: Florida Agricultural Experiment Station.

State Plant Board of Florida. 1917. Annual Report, 1916. Gainesville: Florida Experiment Station.

UF/IFAS Citrus Research and Education Center. History.

Webber, H. J. , W. Reuther, and H.W. Lawton. 1967. History and Development of the Citrus Industry. In The Citrus Industry, Vol. 1 eds. W. Reuther, H.J. Webber and L.D. Batchelor. Riverside: University of California Board of Regents.

Wilmoth, K.M. 2014. Retracing citrus’ earliest roots to find clues for healthier future. IFAS News Service. June 9, 2014.


Posted: September 12, 2014

Category: Smith-Lever, UF/IFAS Communications, UF/IFAS Extension
Tags: Agriculture, Citrus, Citrus Greening, Diseases, Freezes, Smith-Lever Anniversary

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