DENVER – With two states now allowing recreational marijuana sales, curious minds want to know: Whose pot is better?

Washington joined Colorado on Tuesday in allowing marijuana sales, and retailers in Washington are bracing for long lines and high demand. The same happened when Colorado legalized recreational sales Jan. 1, and tens of thousands of buyers got the chance to pick from a wide variety of strains, from Blue Dream to AK-47 and Facewreck.

Those names represent known genetic strains of marijuana plant – think Macintosh and Granny Smith apples – that are cultivated the world over. But even through the genetics are the same, how the plants are grown makes an enormous difference, experts say. That makes it all but impossible to make consistent comparisons.

“It’s all about who you have behind your warehouse. A lot of people here focus on bulk over quality, and it’s widely recognizable,” said “budtender” Michael Morones of Mile High Green Cross of Denver, which bills itself as a premium medical-marijuana store. “It’s a day and night difference, and you can find that in any state in the country.”

Yes, like wine grapes, the terroir of your tetrahydrocannabinol matters.

And for first-time retail buyers, suddenly far more options are available than whatever your friend’s friend was offering to sell in the grocery store parking lot. Walking into a marijuana store offering more than a dozen strains of buds along with a wide variety of pot-infused edibles can be an intimidating experience for someone used to buying small amounts through friends.

“The soils, the growing temperatures, the amount of light, the humidity are all important factors,” said federal marijuana researcher Marilyn Huestis, the chief of chemistry and drug metabolism at the Intermural Research Program at the National Institute on Drug Abuse.

Colorado’s marijuana stores are selling organically grown, but not certified, marijuana with incredibly high potency that can taste like anything from blueberries to cheeseburgers.

Washington state’s supply will be tight in the beginning because of tight regulation, but supply is expected to quickly grow. That means people looking for a brain-focused high can buy a different kind of pot than the guy who just wants to get, like, totally stoned and crash on the couch.

Experts that USA TODAY consulted say two growers who start with exactly the same seeds can end up with significantly different products, especially when it comes to the level of THC in the plant.

That’s why so many growers use indoor hydroponic systems, which give them near-absolute control over lighting, fertilizer, water levels and pest control. In an effort to maintain consistency, many growers don’t start a crop from seed but instead take cuttings from more mature plants.

Morones, a former pharmacy technician, quit his mainstream job to work in Colorado’s growing marijuana industry precisely because of so many variations in the plant. He said novice buyers are going to be blown away with the selection and quality of the marijuana available through the state-regulated stores in both Colorado and Washington.

“It’s amazing that you can literally have something thrown in your bowl that tastes like lemonade and then the next bowl after that tastes like a cheeseburger,” he said

Even how someone smokes marijuana – or eats it, vaporizes it or rubs it on their body – makes a big difference on the eventual effect, Huestis said. For instance, smoked marijuana hits people much faster than pot-infused edibles, which can last longer and be much stronger because it’s far harder to limit the dose.

Both Colorado and Washington require growers to test their crops for potency.

Many first-time users probably won’t be able to tell one strain from another, said Lucas Fiser, a marijuana columnist for the Denver Post’s Cannabist section, who has been documenting his experiences combining marijuana and exercise. He said novices are best off starting with low doses rather than trying to get the strongest pot they can find.

“Let’s be honest. New users are really only going to feel high,” he said. “They won’t have a taste or feel for the differences yet.”

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