In this Dec. 13, 2017, file photo, a marijuana plant grows under artificial light at an indoor facility in Portland. Credit: Robert F. Bukaty / AP

Marijuana businesses in Maine’s largest city have reached the final day to apply for retail store licenses.

The deadline to apply for a marijuana retail store license in Portland was Monday. The city’s marijuana ordinance took effect in June. The ordinance caps the number of licenses for retail marijuana stores at 20.

Portland’s rules also establish a 250-foot buffer between retail stores and a fee schedule.

Maine voters approved legal adult-use marijuana sales in 2016, but the roll out has been slow. The first retail marijuana businesses in the state are expected to open in October.