Not officially, of course. But the "wacky tabacky" has been spotted sprouting this summer in a city planter on Main Street and on the grounds of City Hall.
City gardeners are taking it in stride.
Maryanne Siegendorf, the city's top gardener, says when crews find the fledgling plants, they pluck them and place them in bags of, um, weeds.
It all causes more giggles than concern. Siegendorf hasn't called the police. "They're so small the police wouldn't care about them."
So who's behind the pot plot? Perhaps a constituent taking to heart Mayor Rocky Anderson's one-time suggestion that marijuana be decriminalized?
Nah. Siegendorf suspects it's more of a prank than a real effort by pot heads to cultivate cannabis on city property. City crews weed flower beds every couple of weeks, which doesn't provide enough time to grow smokable dope.
"I don't know if they just, you know, are walking by and say, 'Hey, let's toss our seeds down there,' " Siegendorf says, adding that the growers would have to be "desperate" to smoke the starts.
And a Web site devoted to helping people cultivate marijuana advises against growing in high-traffic areas to avoid cops. Planting inside a dense field of brush is smarter, advises "Leaf" on overgrow.com.
Last month, while weeding Main Street planters to prepare them for new flowers, Siegendorf noticed a 4-inch-high plant in the city pot in front of KUTV Channel 2's studios.
Marijuana plants look like elm trees when they are small, so how would Siegendorf know it was ganja?
She laughs and says she recognized it from Deadhead T-shirts.
Earlier this month, another crew discovered "several" marijuana plants at City Hall (where gardeners sometimes find potatoes and tomatoes being grown) while beautifying the grounds in preparation for the Jazz Festival.
Gardeners also have come across marijuana plants in years past at Liberty Park -- think drum circles -- and Jordan Park's International Peace Gardens.
An amused Siegendorf has a message for burnouts: "We're on top of our weeding."