Lemon Grove is a city in San Diego County, California, United States.

After Mexico became independent from Spain, the Californios (residents of Alta California) ranched on various land grants.

The area that now includes Lemon Grove was granted to Santiago Argüello, who received more than 59,000 acres.

[7] The first proprietor of Lemon Grove, Robert Allison, arrived in the region in 1850, coming from Sacramento.

He purchased thousands of acres from Santiago Argüello's heirs; this land eventually became Lemon Grove, La Mesa, Encanto, and part of Spring Valley.

The climate was suitable for the cultivation of subtropical fruits and vegetables, and farmers from the East and Midwest flocked to the region.

"[7] Joseph and Anton Sonka, immigrants from Bohemia, moved to Lemon Grove after stints in Seguin, Texas, and San Diego.

"[7] In the Lemon Grove Incident in 1931, Mexican American parents in Lemon Grove pursued a successful judicial challenge against the decision of the local school board to build a separate school for Mexican American pupils.

The decision of the Superior Court for San Diego County in Alvarez v. Lemon Grove was the first successful lawsuit against school segregation.

[7] Lemon Grove was incorporated as a general-law city;[10] however, it continues to receive law enforcement services, via contract, from the San Diego County Sheriff's Office.

[12] According to the United States Census Bureau, the city has a total area of 3.9 square miles (10 km2), all land.

It is also served by the San Diego Trolley's Orange Line, at Lemon Grove Depot as well as at Massachusetts Avenue Station.

According to estimates by the San Diego Association of Governments, the median household income of Lemon Grove in 2005 was $55,436 (not adjusted for inflation).

When adjusted for inflation (1999 dollars; comparable to Census data above), the median household income was $45,016.

Public primary education in the city is provided by the Lemon Grove School District.