The Big Island’s first marijuana production center got the green light Tuesday to begin growing plants, a year after Hawaii’s first dispensaries opened on Maui and Oahu.

Hawaiian Ethos LLC, one of two dispensaries on the island, received the OK from the Department of Health nearly two decades after the state approved the drug for medicinal use. Lau Ola, run by Big Island farmer Richard Ha, is the last of the eight dispensaries that were issued licenses to grow and sell marijuana in April 2016 yet to begin operations.

“All of the licensees have worked hard to meet state standards to create a quality industry in Hawaii that provides a safe product while ensuring patient and public health and safety,” said Keith Ridley, chief of the DOH Office of Health Care Assurance. “We will continue to work diligently with Hawaiian Ethos as they complete construction of their second production center and then seek approval for retail sales.”

Six out of eight dispensaries, which sell medical marijuana that is tested for quality and safety, have opened on all the major islands except Hawaii island. There were 21,705 patients statewide as of July 31, with 31 percent of medical marijuana cardholders living on Hawaii island.

“We continue to diligently work with the county’s agencies to allow our dispensary doors to be opened at the earliest time possible,” said Diana Hahn, spokeswoman for Hawaiian Ethos.

County permitting and other government requirements were a large part of the significant delays for Lau Ola and Hawaiian Ethos, whose CEO Bill Richardson died in November. He was replaced by interim CEO Luis Mejia.

The state legalized medical cannabis in 2000, but patients had no legal way to obtain the drug until Maui Grown Therapies opened on Aug. 8, 2017, followed the next day by Aloha Green Apothecary in Honolulu. The other pot retailers include Pono Life Maui and Noa Botanicals and Cure Oahu in Honolulu. In May, Green Aloha Ltd., doing business as Have a Heart, also started sales.

Each dispensary can operate two production facilities — that each may grow up to 5,000 plants — and two retail centers for a total of 16 production and 16 retail stores statewide. The Big Island retailers are hoping to begin sales by year’s end.