Mostardas was colonized by Azorean immigrants. In 1738 there was already a military outpost called "Guard of the Mustards". The name remained until the beginning of the 20th century, when it became known as Mostardas. On the 18th of January 1773, the Freguesia de Mostardas is created. Later it became the district of São José do Norte. On the 26th of December 1963, the district emancipates itself. On 11th of April 1964, Executive, Legislative, and Judiciary branches were established. Regarding the name Mostardas, there is no documented explanation. One of the hypothesis suggest that the city received its name on account of the large amount of the edible vegetable found in the area. Another hypothesis listed by the historian Marisa Oliveira Guedes is that the name Mustardas was given not by the amount of the plant, which does not actually exist on the fields, but, because Mostardas were the name of the trenches used during the wars in Portugal, which were covered with a mat made of reed and Taquara bamboo, with camuflage made by the plant Mustard, because this plant does not wither.
Book about the city
The book Histórias Antigas de Mostardas, by Jayme Collares Neto, has genealogical information and histories of past inhabitants. It was launched in September 2017. It is available in Mostardas and in bookstores in Porto Alegre, Rio Grande e Pelotas.
Geography
Situated on 31º 06' 25" latitude south and 50º 55' 16" longitude west, at an altitude of 17 meters. The city is part of the south shore of the state of Rio Grande do Sul, on an isthmus formed by Laguna dos Patos and Atlantic Ocean. Its population, as estimated by the Census of of 2010 is 12,124 inhabitants. The climate is humid subtropical. It has an area of 1.982,992 km². It has four beaches. Solitude Beach receives more tourists from other cities, such as the metropolitan region, than Mostardas itself. Balneario Mostardense. Saint Simon Beach hosts one of the city's oldest societies, the Club of Saint Simon, founded in 1948. It still hosts parties, live music, and dinners. The FatherJohn Beach has inhabitants who have been living there for a long time. It has one of the biggest religious festivals of the city during the summer.