Terrariums were mostly regarded as school science projects until New York artist Paula Hayes elevated them to fine art by fusing her love of sculpture and nature.

"That was the beginning of, 'Oh my gosh, I can make this landscape, but you can carry it around,'" she says. 

Terrariums date to Victorian times and enjoyed a moment in the 1960s as a craft.

Hayes began experimenting with them then, and started creating terrariums for an exhibit 15 years ago at Salon 94 on the Upper East Side. That triggered a terrarium trend.

"It touched a nerve, and the ripple effect was that you can see them everywhere now," Hayes says.

One measure of their popularity is that more than 1 million photos of homemade terrariums are posted on Instagram. But perhaps not all terrarium fans are as inspired by these mini-landscapes as Hayes is.　

"My dream, my hope was that that aspect of, 'I can participate in this and care for this,' would expand into something like, 'I can save the world,'" Hayes says.

Hayes' living works have been shown in galleries, museums, and public spaces. She designed a garden at the Salon 94 gallery.

Hayes' terrariums are so popular, Stacey Gengo has built a career by tending to more than 20 of them in private collections across the city.

"I've always been sort of in awe of the creation of something you can hold in your hand and create something that looks like this on a very miniature scale, and the idea that that can be inside of these homes," Gengo says.

One of Paula's largest works is in the Seagram building in Midtown. It's completely visible from the lobby, and it's also accessible from both of the buildings' restaurants.

Whatever the size, Hayes says her works are about the care required to maintain the teeny-tiny ecosystems. She and Gengo are happy if people make their own.

"You need a vessel, need a little gravel on the bottom, a little bit of sand, a little bit of charcoal. Then you can add the soil and your plants," Hayes says.  

Because they are so popular, it is easy to find tiny plants and anything else you might need to build a terrarium. For inspiration, think of it as garden you can fit in a New York apartment.