The weather forecast announces frost for the night. Time to inspect the orchard heaters and fill them up with oil. The smudge pots were developed after a disastrous freeze in Southern California in January 1913 wiped out a whole crop.
When the air temperature reaches 29°F (-2°C) the pots are ignited. For each additional degree of drop, another hole is opened on the control cap. Below 25°F there's nothing more that can be done to enhance the heating effects.
The citrus growers needed a lot of workers to keep the pots burning.
Photo from a brochure
Century Foundry Metal Works (www.showcaseminiatures.com) sells HO scale smudge pots. I painted the white metal castings aluminum with some black on the chimney and also added some Rust-All. Then I placed them between the rows of orange trees.
In this picture from the Library of Congress we see a view of smudge pots in an orange grove on Victoria Avenue in Arlington Heights, Riverside, California. Following WWII, air pollution captured the public's attention and orchard heaters, like smoking diesel trucks and open burning at garbage dumps, were a signigicant and visible source of smod. In 1950, the Orange County Air Pollution Control District adopted a regulation prohibiting the use of dirty fuels, including old tires and used motor oil in smudge pots.
During the 1950s, growers started using wind machines in place of smudge pots. But orchard heaters only fell out of use completely by the 1970's (!!)
The ground between the rows of citrus trees was regularly plowed and disked to smooth the earth. Weeds were controlled by chemicals like weedoil and others.
Stay tuned for more on modeling an orange grove