Roses on Valentine’s Day don’t seem like such a kind gesture when you think about them getting shipped to the city on cargo planes from Ecuador, or decomposing in landfills and converting to methane gas.

So what’s a climate-conscious romantic to do?

Consider the case of Leatal Cohen, an idealistic young florist and the owner of Pic and Petal. She was hired by a man who wished to propose to his girlfriend while surrounded by hundreds of flowers. Yes, it would be beautiful and lavish. But wasteful, too. Could she temper it somehow?

“You know when you cook food, and there are leftovers, and they just go into the garbage?” Ms. Cohen said. “It just doesn’t feel good, even though you know it was enjoyed.”

So, a few hours after the newly engaged couple’s fairy tale moment, Ms. Cohen asked Aviva and Arielle Vogelstein, sisters and the founders of ReVased, which repurposes and resells slightly used floral arrangements, to dismantle and transport the 350 proposal flowers to Ms. Cohen’s apartment in Downtown Brooklyn.

There, the Vogelstein sisters paid Ms. Cohen a few hours work to help them sort through the anemone, ranunculus, delphinium, privet berry, pear flower blossom, hydrangea and garden roses, as they figured out how to create new arrangements. Some would be going to subscribers who receive a delivery once a month for $29. The rest would be donated to a Lincoln Square neighborhood center.

ReVased customers “don’t know exactly which flowers they are going to get,” said Aviva Vogelstein, who quit her job this month as a lawyer to work for the company full time. “That makes it exciting.”

Office space, scooters, and now, floral arrangements: The sharing economy has trickled down to the flower industry, with more companies across the city committed to either extending the temporary joy flowers bring or to reusing or composting them more responsibly.

After all, flowers are big business, and there’s room for growth. This year, for Valentine’s Day alone, Americans are expected to spend $2.3 billion on flowers, up from $1.9 billion last year, according to the National Retail Federation.

In a city like New York, where special events happen on a daily basis and cut flowers are in demand year-round, it was only a matter of time before eco-minded entrepreneurs saw an opportunity.

“Valentine’s Day is an incredibly wasteful holiday in terms of its environmental impact, but if you’re looking at the year as a whole, events are way worse,” said Liza Lubell, 37, who runs Peartree Flowers, which specializes in large installations.

A typical large event like a wedding or gala can produce up to 100 bags of flowers, Ms. Lubell said. “It’s not just centerpieces on a table anymore,” she continued. “The whole ceiling could be filled with flowers.”

So Ms. Lubell created a second company, Garbage Goddess, which provides eco-cleanup services for events in New York City, the Hamptons, the Hudson Valley and soon, Los Angeles. “We try to find alternative homes for everything,” she said. “We look at recycling as our last resort.” Her goal is to have less than two bags of garbage for each event.

Often, Garbage Goddess will donate event flowers to textile designers like Cara Piazza, who uses the flowers to make natural dyes in her Brooklyn studio.

“One bouquet from a wedding will get you a scarf and a kimono,” Ms. Piazza said. “I will get nine massive garbage bags full of flowers from events that will last me a month.”

“Flower repurposing is one of the biggest things happening in the events industry right now,” said Nicki Fleischner, the founder of Plan with Purpose, a website that showcases ethically-minded event vendors. “There are more companies coming out of the woodwork all the time.”

Credit…Brittainy Newman/The New York Times

Jennifer Grove, an event planner, started Repeat Roses in 2014. Her company will pick up flowers after an event, restyle them, and transport them to a local nonprofit, like the Dwelling Place, a women’s homeless shelter and a regular recipient. When the flowers wilt, the company will deliver them to a composting facility. “To date we’ve diverted 197,137 pounds of waste from landfills,” Ms. Grove said earlier this month.

But Ms. Grove’s services aren’t cheap. Flower handling fees start at $1,750. This might explain the company’s heavy celebrity following.

Last Sunday, for example, Repeat Roses transported 590 pounds of florals from the Vanity Fair Oscar Party in Beverly Hills to the nearby Ronald McDonald House and the East Los Angeles Women’s Center. And last February, it collected flowers from the baby shower for Meghan, Duchess of Sussex, at the Mark Hotel on the Upper East Side and took them to local charities, including the American Cancer Society Hope Lodge. The flowers were later composted.

Of course, people could also forgo flowers altogether, said Elizabeth Balkan, director of the food waste program at the Natural Resources Defense Council. “We are not going to compost our way out of the flower issue, because there is still an enormous amount of resources used to create them,” she said.

In other words, why did the Duchess of Sussex, a self-proclaimed environmental advocate, have 389 pounds of flowers as part of her baby shower in the first place?

Because people love them, so to cancel them is unrealistic, said Jenny Flax, an event planner who has convinced many of her clients to use Repeat Roses for bar and bat mitzvahs. “People want to use flowers, but you can help them see how the amount of waste is alarming and what they can do to help.”

Ms. Balkan, like Ms. Cohen of Pic and Petal, compared rotting flowers to food waste. “A loaf of edible bread that has gone moldy and is composted, that is not a win,” she said. “That bread shouldn’t have gone moldy. It should have been frozen or given to a friend or used to make bread crumbs.”

Individuals who receive flowers can do their part as well, Ms. Balkan said. “Press them, repurpose them, turn them into soap,” she said. Or refuse them altogether. “I’ve seen people give potted plants or herbs as gifts.”