Tagged cannabis plants grow in the Outliers Collective's cultivation facility in San Diego County, California in October 2016. Colorado is the only state that allows individuals to grow more than 16 plants per residence. (Vince Chandler, Denver Post file)

Colorado marijuana mega-grows: How much is too much?

Of the 28 states that have legalized marijuana for adults or patients, 12 ban home cultivation and no other state allows people to grow more than 16 plants in their homes.

There is no true limit in Colorado.

A medical marijuana patient can get a doctor’s permission to grow as many as 99 plants. A caregiver can grow the plants for numerous patients in their own homes with no hard limit.

On the recreational side, the Constitution promises individuals can grow no more than six marijuana plants with three or fewer being mature, flowering plants. But a house with five roommates expands that to 30 plants in a house, and some stretch the law even further and co-op their plants into mega-grows.

Colorado should not tolerate this behavior.

Lawmakers should pass House Bill 1220, which would limit grows in residential areas to 16 plants per house regardless of how many people live in the house or what their medical marijuana plant count is.

The bill is the latest effort to crack down on the least regulated aspect of legal marijuana in Colorado, and it’s long overdue. In 2015 lawmakers required caregivers to register with the state. That took full effect in January and should help crack down on those who pose as caregivers to grow marijuana outside of the regulated industry permitted to grow for commercial purposes.

But additional loopholes remain.

These large marijuana grows can hurt neighborhoods. Personal use or medical supply grows are mostly smelly inconveniences to neighborhoods.

But those marijuana plants cultivated for illegal distribution can bring with them a criminal element.

Sheriffs Bill Elder and Kirk Taylor testified in the first committee hearing on HB 1220 about the impacts unlicensed and unregulated marijuana grows have had on their communities, El Paso and Pueblo counties, respectively.

Elder estimates El Paso County has more than 40 unlicensed grows right now that have over 200 plants and over 100 grows with more than 100 plants. He said there’s no way for his deputies to know if a grow is a legitimate co-op for medical marijuana patients or one of the many illegal networks of growers who ship pot out of state for profit.

That’s not what voters signed up for when they agreed to legalize marijuana.

Lawmakers need to clean up this mess, and HB 1220 is a good step. The bill also includes important protections for medical marijuana patients who have legitimate reasons to grow many plants. Those patients can apply for an exception from their local government to grow more than 16 plants or they can find an industrial or agricultural site to grow in.

That seems fair to us.

The bipartisan authors of the bill — Rep. KC Becker, D-Boulder, and Rep. Cole Wist, R-Centennial — have crafted a smart compromise bill that avoids shutting down home grows altogether. Gov. John Hickenlooper in November called the gray market a “clear and present danger” and asked lawmakers to help him close down the loopholes. We hope they do so this session.

Regulation of Colorado’s marijuana experiment is an ongoing process, and this certainly won’t be the last time lawmakers tackle home grows. But this is an important and immediate step that can help law enforcement locate illegal grows and shut them down.

To send a letter to the Denver Post editor about this article, submit online or check out our guidelines for how to submit by e-mail or mail.

This story was first published on DenverPost.com