Michael Bayard, owner of Capital City Hydroponics, is pictured near a growing supply display in the store. The colored light is from the growing lamps on display. (Sarah L. Voisin/The Washington Post)

In a narrow Petworth basement stuffed with high-end gardening supplies, Michael Bayard gingerly explains that tomatoes are best grown indoors given the District’s unfavorably dank weather.

Tomatoes, it turns out, are cultivated similarly to marijuana. And since his shop, Capital City Hydroponics, opened in 2011, Bayard has often explained to customers how to grow the food — tacitly aware that some of them just go home and use their new tomato knowledge to grow pot.

But marijuana was legalized in the District on Feb. 26, which means Bayard can talk openly to customers about growing the plant all he wants. Initiative 71 — the law that D.C. voters overwhelmingly approved in November — allows people to possess up to two ounces of marijuana and grow a maximum of six plants in their homes (with up to three mature at one time).

As a result of intervention by the Republican-controlled Congress, selling marijuana is still prohibited in the District, making Bayard’s niche store uniquely positioned to benefit from the law. And Capital City Hydroponics isn’t the only business looking to cash in: From marketing firms to security companies, a number of business not traditionally associated with marijuana are making a play for a now-viable market in Washington.

Referencing Congress’s repeated attempts to kill the local initiative, Bayard says marijuana won’t be mentioned too much in the store because he wants to maintain his family-friendly business reputation and ensure that marijuana legalization is here to stay.

Nutrient supplements for plants are stacked neatly on shelving at Capital City Hydroponics, located in the Petworth neighborhood of Washington. (Sarah L. Voisin/The Washington Post)

“Something that is flowering or fruiting, like tomatoes, or something else, right? Then you are going to need a flowering stage where the fruits and vegetables can mature,” Bayard said in his shop one afternoon before legalization took effect. “So this is how I talk to customers.”

Still, the weekend after Initiative 71 took effect, Capital City Hydroponics ran a sale of the indoor gardening kits needed to grow marijuana — the cheapest one started at the gimmick price of $420 — and, according to Bayard, business doubled. His neighborhood shop, he said, felt like the more bustling Metro Center area downtown than a typically sleepy Petworth alleyway.

Countless studies have already looked at how much the economy, both locally and nationally, could gain if marijuana is legalized and regulated. The District’s Office of the Chief Financial Officer estimated last year that, if the city were to tax the drug, marijuana could balloon to a $130 million annual industry here.

But determining how much the city and local businesses could make from the current law — which prohibits sales and regulation — is a bit more complicated, particularly considering that many would-be customers have long been purchasing marijuana-related paraphernalia, albeit typically under the guise that they’d be using the gear for something other than marijuana.

“The real type of economic opportunities come directly from selling cannabis,” says Malik Burnett, the policy manager for the Drug Policy Alliance, adding that, for now, the biggest economic benefit for the District comes from the reallocation of funds the city would have otherwise used to enforce laws and imprison residents for marijuana-related crimes.

So cannabis may not directly bring an extra $130 million to city coffers just yet, but Adam Eidinger, who spearheaded efforts to put Initiative 71 on the ballot, is working to guarantee that it brings in at least some new cash. He plans to reopen his Capitol Hemp shop in Adams Morgan this year now that marijuana is legal. The D.C. government forced him to shutter the shop in 2012, saying the merchandise he sold, including pipes and vaporizers, were in violation of the city’s drug laws. When he reopens Capitol Hemp, Eidinger plans to stock the shop with the same type of items.

“If you said you were going to use the pipe for marijuana, we would tell you to leave,” Eidinger says. “We don’t have to play that game anymore.”

As of February 26, marijuana is legal in D.C.—sort of. Here are the ins and outs of the complex new pot law. (Gillian Brockell/The Washington Post)

Island Dyes, a similar type of paraphernalia shop that opened last summer in the H Street NE area, is openly advertising on social media that it sells marijuana-related items now that it’s legal.

“Time for a fattie,” an Instagram post reads under a picture of eight large, tightly rolled marijuana joints. The post also features the hashtag: “It’s legal in D.C.”

And while that blunt advertising seems directed at a very specific audience, it’s working: Since marijuana was legalized, store owner Glen Schow says business has nearly tripled.

“It’s been so busy, I’m exhausted,” says Schow.

Businesses poised to benefit from legalization go beyond purveyors of high-end bongs and paraphernalia.The weekend after legalization went into effect, a cannabis convention came to town, and dozens of businesses showcased how they could contribute to the industry. Yes, there were shops that sold paraphernalia and schlocky marijuana-related apparel. But there were also more unexpected businesses, like Abe Garcia and TJ Cichecki’s two-man creative branding firm, Workhorse.

They’ve been operating out of a co-working space in Northeast for more than a year and work with some nonprofit groups in the area. Now, they’re trying to add pot businesses to their portfolio of clients.

“I’ve never seen such a low barrier to entry,” Cichecki said of the pot industry, adding that he wants to help businesses move away from the teenage-boy/Bob Marley images associated with pot and move toward more sophisticated branding associated with vineyards or beer breweries. “This cannabis industry is serious, it’s not going away. We want to help people craft this new image.”

Other businesses can’t fully benefit from the marijuana law just yet. Jonas Singer, one of the co-founders of Union Kitchen — a local incubator focused on fledgling food businesses — knows that marijuana and food could be a profitable combination.

If a Union Kitchen member wants to market its food business to hungry marijuana users without actually selling the drug, Singer says he’d be okay with that. And, if and when it’s legal to sell marijuana in the District, Singer says he’ll welcome chefs and businesses that sell edibles.

“Hell, yeah, we will,” Singer said. “And you can quote me on that.”