Territory annexed to the city subsequent to the effective date of the ordinance codified in this title shall, upon the date that the annexation becomes effective, become a part of the agricultural zone. In the case of uninhabited territory being annexed to the city, the Planning Commission may recommend and the City Council may adopt zoning regulations for the territory, in which case the regulations shall become effective when the annexation becomes effective.
(`78 Code, § 17.02.050.)