WINDSOR — When 28 Windsor residents showed up last year to set rules for cannabis businesses, the bylaw they created left an opening wide enough to drive a greenhouse through.

At least one with wheels.

"A Marijuana Cultivator," the rule declared, "may operate Marijuana Cultivation Facilities on any property within the Town."

Seventeen months later, the Planning Board proposes to take revised wording to a special town meeting Sept. 9. The changes will be aired at a Planning Board hearing at 7 p.m. Tuesday.

A draft of the revised bylaw specifies how cultivation can occur in Windsor, both indoors and outside.

"When we put the bylaw in, everyone was thinking retail, not cultivation," said Kim Tobin, chair of the Select Board.

The move to tighten what's allowed comes after a project outlined by Green Theory Cultivation LLC roiled neighbors in the Monahan Road area this spring. That plan for a greenhouse cultivation site, submitted in early July by Harsh Patel, will be reviewed by the Zoning Board of Appeals in the town offices at 7 p.m. Aug. 29 under the existing 2018 bylaw.

Among other changes, the revised rules spell out that indoor cannabis cultivation must use "state of the art" odor control methods. Outdoor growing sites can be located only on lots with a minimum of 10 acres of space and 500 feet of road frontage. They must also be surrounded by at least 100 feet of undeveloped land.

No change is proposed for where retail operations can locate in Windsor. That would remain restricted to an "overlay district" on the north and south sides of Route 9, close to the town center.

In the definitions section of the bylaw revision, the town would widen the definition of cultivator to include research facilities or craft marijuana cooperatives, in which a group of small growers share a state-licensed facility.

The new rules would also require proposed cultivation sites to submit security plans. And on an environmental matter, they would require growers to specify how they would obtain water, and in what amounts.

One proposed passage in the revised bylaw would allow cultivators to seek a permit to extract THC, the main psychoactive ingredient in cannabis, or non-THC oils or other plant products.