When I look at this photo, I see "Sunset Magazine" and a very modern romantic version of rustic Spanish California.
The adobe was originally built after the secularization of Mission San Jose. Supposedly built by José de Jésus Vallejo for his vaqueros. JJ Vallejo grew wheat and cattle.
According to Charles Howard Shinn, writing in the Oakland Enquirer in 1889, "The late Thomas Scott was a prominent man of Vallejo Mills. He moved there [Vallejo Mills] after a year or two of farming "on the bottom," where he lived in the old adobe still standing on the California Nursery Grounds."
According to Frances Roeding, Frank Garcia was born in the adobe in 1867. There was a "hole in the middle of the roof, under which the family cooked, so that the smoke could go out, and some fresh air could come in. Each corner of the structure was used for a different purpose. One corner was used for sleeping, another for storage of supplies, the third for quarters for domesticated fowl and animals, and the fourth for a family chapel."
When John Rock came here in 1884, this was the only building on the 463 acres. Did they live here until they were able to build some housing? It was later used for cold storage and fumigation. It had no windows and had a shake roof. There was a wooden extension on the west side, as seen in the Washington Township book.
Again from Frances "When George C. Roeding, Jr. took over management of the California Nursery from his father in 1926 the "Old Adobe" was used as a storage shed for late export nursery shipment so that the stock would be kept cold and dormant." It was surrounded by lath houses and sheds on all sides.