HALF MOON BAY, Calif. — John Muller steered his tractor left onto Main Street, four Atlantic Giant pumpkins in tow, and thousands of people at the pumpkin parade screamed with delight.

But there were many others, spread throughout the festival that day, who feared the famous farmer had led the city down an uncertain path, demanding changes that couldn’t be undone and attempting to enrich himself in the process.

They are determined to stop “Farmer John,” even if it means putting him – and his pumpkin patch – out of business.

On Nov. 6, residents of this small, coastal city will vote on whether Muller, 72, can use a section of his 21-acre farm to grow thousands of young marijuana plants.

Muller and his wife, Eda, said they need this revenue to save their property, Daylight Farms. If voters don’t approve Measure GG, the Mullers could be forced to sell everything before next year’s harvest.

“If that doesn’t pass, there won’t be a pumpkin farm,” Eda Muller told critics at a recent City Council meeting, muttering under her breath, “Put that in your pipe and smoke it.”

U.S. farmers last year harvested 2 billion pounds of pumpkins, many of which were later carved into spooky or silly faces for Halloween. The economics behind these Jack-o’-lanterns can be as messy as their gunky guts, though, with everything hanging on six weeks of sales. But these and other iconic American holiday symbols exist in an often overlooked economy with hidden pressures and pain.

For California farmers – many struggling like the Mullers – the state’s legalization of marijuana has offered the prospect of raising a lucrative crop that could keep them on their land. They must first win the approval of their communities, and the debate dividing Half Moon Bay has also paralyzed other parts of the state.

Local governments, particularly in remote rural areas, are deciding whether cannabis should be treated like any other crop or banned, out of concern that it could lead to crime and other unwanted social change. Calaveras County, for instance, allowed the cultivation of cannabis, collecting millions of dollars of taxes, only to backtrack. Now growers are suing.

John Muller’s pumpkins are a big hit in Half Moon Bay, but locals are leery about his plan to grow cannabis, fearing potential crime and social change. Washington Post/Ricky Carioti

Here in Half Moon Bay, 130 miles to the west, John Muller’s plans are straining the entire city, pitting neighbor against neighbor, past against future. The choice is about more than farming and economics, reaching into the community’s sense of values. Voters must decide whether to welcome commercial cannabis inside their community and help the farm, or stand firm against marijuana and possibly smash the Mullers’ pumpkin business.

In a city that calls itself the World Pumpkin Capital, losing the Mullers’ gourds could be a devastating turn of events. Their iconic roadside plot draws wealthy visitors from San Francisco and Silicon Valley for more than a month each autumn.

And the Mullers are the only local farmers who have shown the ability to raise Atlantic Giants, pumpkins that can gain 40 pounds of weight each day and grow to the size of small cars. These orange boulders give the city a connection to its agricultural past, something many residents are scrambling to protect.

Some competitors have boosted revenue by adding haunted houses, hayrides and corn mazes to their farms, but the Mullers have eschewed such agritourism, describing themselves as purists.

Giant-pumpkin farmers, though, are known for being secretive and wily, and many residents don’t trust the Mullers’ motives despite their increasingly desperate pleas.

Opening Half Moon Bay to commercial cannabis could change the city forever, they worry, normalizing pot for teenagers, luring outside investors with nefarious motives, and drawing federal scrutiny upon farm laborers, many of whom are undocumented Mexican workers.

“To say there are no other crops that a farmer could grow in Half Moon Bay is ridiculous,” said Virginia Turezyn, who works at a business advisory firm and is running for City Council on the same ballot as Measure GG. “They could grow Brussels sprouts. They can grow other stuff. . . . Everybody thinks (cannabis) is a cure-all and a panacea, but I’ve read tons of research that highlights tons of negative implications for the community, for crime, for youth and for the stench.”

The Mullers grow 60 varieties of pumpkins, gourds and squash, including Cinderellas, Fairytales and Tonda Padanas. They plant 80,000 seeds each spring, and each seed can produce up to four pumpkins. Harvest takes one month, and then the pumpkins are sold at a plot called Farmer John’s Pumpkins on the Pacific Coast Highway, where visitors can see the ocean peaking across a crest of trees.

Muller has always been more than just a farmer, though. In 2008, he served his first of two terms as mayor, helping steer the beleaguered city away from bankruptcy. He also served in other local government posts and advised the U.S. Agriculture Department during the Reagan administration.

At his pumpkin patch, he’s a dusty blur, working as greeter, cashier, wheelbarrow pusher and parking director. He’s 5½ feet tall and wears a deep tan on his face from farm work.

On a recent Friday, he was constantly in motion, sporting torn green coveralls and a sweat-stained hat, hugging visitors and pulling wagons and directing people to a tepee past the hay bales.

He looked at times joyful and at times exhausted, saying he had been up at 4 a.m. discussing the farm’s future with Eda. The Mullers still care for Adreveno, now 95, and his wife, who is 90.

“The family estate is dwindling – we’ll have to make some very, very, life-altering decisions,” he said. “We worked hard all our lives, but our little bodies are slowing down a bit.”

At this year’s pumpkin parade, Eda sat near the back of the float being towed by her husband, behind the four giant pumpkins they had borrowed because their Atlantic Giants were too small. Her mother’s health was failing, she knew, and maybe the farm’s fate was beyond her control. Two weeks after the festival, her mother passed away.

Eda Muller waved at times during the parade, but at other times she just sat there, staring out at the crowd behind large sunglasses. The cannabis vote is next Tuesday, and the Mullers will know their fate then.

In a text message a few hours later, she wrote that the whole parade was “bittersweet because we don’t know if it’s our last one or not.”