Mackie Barch and a team of workers wore plastic sleeves and latex gloves to fend off the plants’ sticky and smelly resin, clipping stalk after stalk in what industry experts said is the first such harvest in this part of the country.

“It’s a race against the clock to get it out of the field,” said Barch, owner of the medical cannabis cultivation company Culta, which launched the multimillion-dollar experiment.

Marijuana farms in Northern California and Oregon have been growing pot plants outdoors for decades. Farms in Colorado are plentiful, too. But commercial growers on the East Coast until now have cultivated marijuana in warehouses or greenhouses.

Partly, that’s because the region has been slower to adopt legal marijuana industries. But mostly, it’s because the humid climate and variable temperatures on this side of the country create less-than-ideal conditions for outdoor cannabis.

Workers trim cannabis leaves from the plants’ flowers at Maryland’s first legal outdoor marijuana harvest. (Jahi Chikwendiu/The Washington Post)

“You need six months of hot, dry days with cool nights, which few East Coast places have,” said Michael Wheeler, a vice president with Flow Kana, which works with hundreds of small outdoor marijuana farmers in Northern California.

“No diss against indoor, but outdoor is a totally different product,” Wheeler said. “If you’ve ever experienced the satisfaction of a ripe, sun-grown tomato from a farmers market, then you can appreciate the difference between outdoor grown cannabis and indoor.”

Culta, one of about a dozen legal medical cannabis cultivators in Maryland, mostly grows indoors, in a warehouse that cost more than $10 million and controls the strength of the breezes, the pH of the water and the wavelengths, duration and intensity of the light.

Mackie Barch, president of Culta. (Jahi Chikwendiu/The Washington Post)

But all that effort to artificially replicate ideal growing conditions is also expensive, roughly three times the price of putting irrigated plants in dirt outside. And as the still-new industry rapidly expands, growers can’t borrow from banks to finance their growth, in part because most financial institutions won’t lend to an industry that the federal government still considers illegal.

As an alternative way to raise cash, Barch and his investors decided to take their chances, setting up an outdoor operation near their warehouse in a downtown Cambridge industrial area, on land Barch says was once home to a tuna cannery.

If Culta could grow cannabis outdoors for a third of the price, the company reasoned, it could plow the higher profit margins into more expansion.

And as the only outdoor cultivator in Maryland, Culta could theoretically perfect the process and corner the market in “sun-grown” cannabis, which is often marketed as organic and sustainable, with a lower carbon footprint.

But the same way that heirloom tomatoes can vary widely in appearance, “sun-grown” cannabis can appear imperfect. Longtime marijuana lawyer and consultant Brian Vicente said that, though outdoor cannabis connoisseurs may beg to differ, “in general, it’s not viewed as much as a high-quality product.”

For now, Culta plans to use all of its outdoor harvest for making processed cannabis products, such as dabs, tinctures and vape cartridges, rather than selling the whole flowers for smoking.

Massachusetts also permits large-scale commercial, outdoor cultivation. But none of the four companies approved to grow outdoors in Massachusetts have begun operations, regulators there said.

In Maryland, outdoor cultivation is effectively banned in some places by local zoning laws that regulate the scent emitted by cannabis plants. Other states have imposed restrictions because of safety concerns.

Roughly an acre plot of cannabis grows at Culta’s outdoor facility in Cambridge, Md. (Jahi Chikwendiu/The Washington Post)

Vicente, whose Colorado-based cannabis law firm represents thousands of clients across the country, said those limits could ease as marijuana markets mature. When consumers become more interested in the benefits of outdoor cannabis — price and otherwise — he said, regulators tend to follow suit.

“There’s a sort of rule of thumb that when marijuana first becomes legal, it gets regulated like plutonium,” Vicente said. “Most states don’t begin by allowing outdoor cultivation.”

For Culta’s experiment, Barch had to clear four inches of soil across three acres, much of it contaminated in the 1989 Cambridge Butter Fire, a multiday grease inferno in a nearby warehouse that had stockpiled 750 tons of butter, along with what news reports described as “millions of pounds of pork ribs, Butterball turkeys, hot dogs, crab cakes, eel and mackerel.”

The company then brought in dump trucks full of dirt to raise the entire area by 18 inches, enough to keep most of the plants’ root systems out of the local water table.

In late July, work crews planted a little under an acre with hundreds of different types of marijuana plants, each plant worth several thousand dollars. As the plants grow, workers manicure them, altering their natural Christmas-tree shape into something that resembles a crepe myrtle — an upward and outward spreading plant, heavy with flowers.

“To the inexperienced eye, these all look like big, smelly marijuana plants. But if you look at them for a while, you can tell how different they are,” said Dave Myrowitz, Culta’s outdoor cultivation manager.

He pointed out a spindly, light-green plant, then a squat, deep-green one with purple veins in its flower. One plant smelled like powered orange Gatorade, another like a grape Fruit Roll-Up, and another gave off an aroma that smelled a little like cookies.

Dave Myrowitz harvests cannabis by clipping the plants’ top flowers. (Jahi Chikwendiu/The Washington Post)

The company harvests its indoor crop every three weeks. But the outdoor field is 20 times larger and requires the temporary workers to help make sure the plants get out of the ground and preserved quickly.

The fact that there’s so much to preserve is partly a matter of luck. This year’s hot summer, which ended with a drought, helped concentrate desirable marijuana compounds. A constant light breeze off the nearby Choptank River helped stave off mold, and there were no battles with unexpected pests — except for one panicked afternoon, when someone discovered an invasive caterpillar.

A sticky coat of cannabis terpenes builds on the Michael Anderson’s gloves as he trims cannabis leaves from the plants’ flowers at Culta in Cambridge, Md. (Jahi Chikwendiu/The Washington Post)

Culta’s cultivators are not only looking for a plant that grows well in this climate. They’re also “pheno-hunting,” which is what cannabis cultivators call the process of identifying a plant that expresses just the right traits (phenotype) to make it a superstar among consumers. Roughly 90 percent of what was planted this year won’t be tried again because the cultivators have deemed those varieties not hardy or distinct enough.

The other 10 percent will be cloned and replanted in bulk alongside more experiments, as cultivators search for a plant that produces the right amount of THC — the main psychoactive ingredient in marijuana — and has a nice variety of terpenes, the oily compounds that give each plant a distinct smell and flavor.

Industry experts said the longer growing season for outdoor cannabis allows the plants to develop and ripen more terpenes, another variable for experimentation that wouldn’t be practical inside a warehouse.