A DC Cannabis Campaign sign is seen with other campaign signs in Washington, D.C., Nov. 4, 2014. This week, campaigners seeking to legalize marijuana and hemp in Ohio received certification from the state's attorney general to begin collecting signatures for a fall ballot initiative. Reuters/Gary Cameron

Supporters of marijuana legalization in Ohio may get a second ballot initiative to vote on this fall. The state attorney general, Mike DeWine, certified Thursday a petition to allow the collection of signatures statewide, local ABC affiliate WCPO reported. The "Legalize Marijuana and Hemp in Ohio" petition is separate from a well-financed campaign by the group ResponsibleOhio, which does not include legalization of hemp.

The newest ballot initiative campaign has to garner more than 300,000 signatures from half of Ohio's 88 counties in order to get their amendment issue on the ballot. ResponsibleOhio's ballot measure, which was certified back in March and has more than $20 million from high profile backers, was expected to reach the required 305,591 valid signatures by mid-June, Ian James, the group's executive director, told WCPO.

Both ballot measures have until July 1 to collect signatures. In Ohio's initiative process, petitions have to get an initial 1,000 signatures from registered voters in any Ohio county. The attorney general can then review the language of the initiative to be sure that it is representative of what campaigners want to do.

A majority of Ohioans favor making it legal for adults to possess a small amount of marijuana for recreational use, according to a Quinnipiac University poll released in April. Support for medical marijuana in Ohio is overwhelming -- 84 percent percent of respondents said they favored legalization, according to the poll. However, support for allowing Ohioans "to legally possess small amounts of marijuana for personal use" was only 54 percent.

Twenty-three states and the District of Columbia have legalized medical marijuana in the U.S. Four of those states have made recreational pot legal for adults 21 and older. Nine states have marijuana legislation or ballot measures in the works this year: Alabama, Florida, Iowa, Missouri, Nebraska, Pennsylvania, South Carolina, Tennessee and Texas.