The Cold and the Dark: A Short, Sooty History

Picking Oranges, ca 1900
Picking Oranges, ca 1900 | Photo courtesy USC Digital Library, California Historical Society Collection

The last nights of 2015 - before the rains came - were clear, and the stars, even against the city's glare, were bright. A rare full moon hung directly overhead at midnight on Christmas Eve, as sharply defined as if chiseled from a chunk of diamond.

There was a time, not very long ago, when growers would have watched through such a fair night with dread.

Hajime Fukuoka, a candidate for a master's degree in Economics at USC in 1918, explained why in almost poetic terms in his thesis The Lemon Industry in Southern California:

Once, in a band of valley and foothill from Oxnard and Santa Paula into the San Fernando Valley and through the San Gabriel and San Bernardino valleys, and on to the plain that descends from the heights of Fullerton to the Pacific Ocean in Orange County, Valencia and Navel oranges and Eureka lemons grew in a grid of orchards, most of them five or ten acres but some a hundred acres or more.

From the air, this "citrus belt" - the Orange Empire, it was called - looked like a obsessive's garden: military files of evenly spaced, dark green trees bordered into squares and rectangles by windbreaks of alternating eucalyptus and Monterey cypress trees.

From tentative, experimental plantings in the 1870s to the apex of the citrus empire in the 1940s, the landscape of inland Southern California was shaped by notoriously temperamental and demanding orange and lemon trees. In Orange County alone, there were than 67,000 acres planted in Valencia oranges as late as 1948 - more than five million trees. (Today, less than 100 acres remain.)

Citrus Smudge Pots, 1928
Citrus Smudge Pots, 1928, | Photo courtesy USC Digital Library, Dick Whittington Collection

The fall of the citrus empire left behind an occasional orange tree in the yards of older neighborhoods, culled from a former grove. Along with them were the memories among older residents of the springtime perfume of the millions of blossoming trees. 

Less nostalgic was the scent of burning fuel oil on cold winter nights.

Cold Terror

Southern California's climate is famous for its mildness, but in many areas of the citrus empire the groves of orange and lemon trees - tropical migrants -- were planted at their climatic margin. For the empire's growers, windless, clear, winter nights brought the "great white terror" of freezing temperatures.

Five hours below 26 degrees in the groves could destroy a year's crop. A week of cold nights would mean the loss of the delicate citrus trees themselves. Replanted at great cost, new trees took as long as seven years to be profitable.

Against the threat of destroying cold, orchardists at first had only hunches, folk wisdom, and luck.

On the basis of a few, optimistic temperature records, large parts of the citrus empire had been sold to investors as being "frost free." They weren't. The slopes of the foothills were less likely to be hit, but freezes covered parts of the so-called "frost free" zones in 1913, 1922, 1927, 1932, 1937, and 1949.

Wrapping trunks and limbs in burlap and straw might hold in some of the tree's latent heat, saving the tree, but wrapping did nothing to save the fruit. Running irrigation water - even warming it in boilers - transferred some heat to the grove, but that tactic was inconsistent. Canvas or wood shelters might be put over the trees to hold in the warmth that radiated up from the ground. These actually worked, but only for growers who could afford the enormous cost of their upkeep.

Misting the grove with water until a rime of frost hardened on the fruit was a paradoxical success. The freezing process actually released heat. A degree or two higher than the air temperature for a nighttime hour or two was enough to bring the fruit through the worst of a cold night. But the problem was keeping the fruit cold long enough to allow it to warm up slowly in the morning sun without the stressed fruit rupturing.

Citrus culture in Florida suggested a better method of keeping the cold at bay. In Florida, unusually cold nights in the orange groves were met with bonfires spaced among the trees. The bonfires combined some science (heated air kept temperatures above 26 degrees) and some folklore (the sooty smoke from the fires was supposed to hang over the trees like a blanket to keep the heat in).


Grove Workers Waiting Out the Night, 1952
Grove Workers Waiting Out the Night, 1952,Photo courtesy USC Digital Library, Los Angeles Examiner Negatives Collection 


Growers here had to adapt the Florida solution. Southern California at the turn of the 20th century had a critical shortage of firewood, not enough to heat thousands of acres of citrus groves night after cold night.

Some growers tried hanging braziers among their trees, fired with coke or charcoal briquettes imported from Australia. Other growers fired wicker baskets filled with straw and the pruned bits of the orange trees. Some burned old tires.

But Southern California by 1900 had an alternative source of fuel - oil and lots of it. Growers bought up low-grade petroleum in tanker lots, mixed the fuel with anything else that would burn in wash tubs and garbage cans and set them alight in the groves.

These burners were the original smudge pots, so called because they produced the dense clouds of sooty smoke - smudge - that growers thought would protect their crop from frost. There were at least a million smudge pots in the groves by 1915.

Black Phlegm

Getting the crude smudge pots into the orchard and getting them lighted safely was hard work that had to be done quickly before temperatures dropped further.

Jared Farmer, in Trees in Paradise: A California History, described what followed a night of smudging the groves. Exhausted workers - often including the grower and his family - would trudge home under the lingering smoke, their faces blackened and coughing up black phlegm. The air inside was hardly better than outside, and oily soot covered every exposed surface, including the walls and ceiling. It might take hours to clean. The smudging might go on night after night.

The effects of smudging were felt far beyond the groves. Because of the basin's inversion layer, the smoke from smudge pots kept close to the ground. The thick soot settled everywhere - on the sanitariums of tubercular invalids, the estates of newly wealthy Angeleños, and the modest homes of the region's growing middle class. Washing was ruined. Buildings were streaked with soot. Some sufferers woke in the night struggling to breathe.

Calls for regulation of smudging - even outlawing it - were continuous from the 1920s onward.

Smudging during the freeze of 1922 shut down the Port of Los Angeles; the low, acrid clouds of soot were too thick to navigate. The port was closed again in 1924, when the daytime darkness was said to be like a solar eclipse. The smudge was so thick in 1937 that motorists at midday drove with their headlights on.

Air quality laws were passed in Los Angeles County and elsewhere, but ignored by small growers and unenforced by the county.

Hard Work

Larger growers in the 1920s began to switch from crude smudge pots to oil-fired units that produced more heat but, unless carefully regulated, still gave off the clouds of dense smoke that some growers continued to believe was protection from the cold.

The new Bolton burners - mostly sold to members of citrus cooperatives - had a shallow reservoir for fuel oil as a base, a reservoir lid with a filler cap and an adjustable air vent, a vapor combustion chamber above, and a sheet-metal stack on top. A hinged cap on the stack aided in shutting off the burner.

Fueling the burners required the grower to have a storage tank and a carrier to deliver oil to the dozens of burners.

Bringing five-gallon buckets of the thick, reeking oil from the carrier to each of the burners was a filthy, wearying task that might have to be repeated through the night. Field workers took what rest they could in the grove while growers worriedly monitored thermometers, calculated the frost point, and listened to the radio for reports from the Weather Bureau's Fruit Frost Warning Service, begun in 1922.

The forecast for overnight temperatures was broadcast 8:00 p.m. on KNX (and later on KFI) from November 15 through February 15. If the report warned of temperatures below 27 degrees, the grower assembled his forces for a night's siege of cold.

To light an orchard heater, a field worker carried a long-spouted torch can filled with kerosene or a mixture of gasoline and oil. A lighted wick in the spout ignited a splash of the mixture in the open fill cap of burner's reservoir. After a few moments, fumes from the heated oil would rise in the combustion chamber to be lighted by the torch can at the top of the stack.

This process, which had its dangers, was repeated for each of the burners until the flames jetting from the stacks made the grove look as if it were on fire.

At dawn, the heaters would be capped to conserve the remaining fuel for the next night of cold.


Downtown Smog, 1952
| Photo courtesy USC Digital Library


G. Carroll Rice, in his memoir of growing up in the groves of El Cajon in the 1930s, recalled that "a 'rippling' or 'purring' sound from the heater's combustion chamber indicated that the air/fuel mixture was burning efficiently."

Running the new burners was expensive. The oil they consumed cost the grower at least $50 an hour (in 1939 dollars) for every ten acres shielded from the cold. Wages for workers added more costs.

Improved burners, introduced in the 1940s, were nearly smokeless if adjusted properly, but the large number of small growers, working on a thin margin of profit, declined to invest in them. Big growers were able to further consolidate their citrus empire, in part through their ability to manage winter freezes when small growers might lose their entire crop and be forced to sell their grove.

Freezes continued as the Orange Empire declined, with more complaints from suburban homeowners about the effects of soot from orchard heaters and new worries about the parallel phenomenon of smog. In 1947, state legislation finally outlawed many types of older, smokey heaters.

Freezing nights in the winter of 1949 brought the last "big smudge" to Southern California. By then, growers had begun experimenting with wind machines - 125 h.p. motors driving aircraft propellers on a tower. The machines stirred the still air over the groves to down the slightly warmer air that lay above the killing cold. The wind machines were mostly effective and didn't have to be tended, as heaters did, by an army of mostly Mexican laborers, But only the largest growers could afford the initial cost.

By 1950, hundreds of small growers in the citrus belt were ready to sell their unprofitable groves. Among the stately orange and lemon trees in neat rows, their branches laden with winter's golden fruit, the developer's bulldozers idled, waiting.

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