Stepping inside the new Madre Cacti shop in northeast Minneapolis is like landing in the desert: The air is hot and dry, the sun beats in through big windows, and there are cactus plants everywhere.

They line the floorboards, sit on display by the window and fill terra cotta pots on racks and the floor. Varieties range from spiny, green-leafed fans to one with brown, stick-like arms. There are plump, spiky bulbs growing on stony rock and tall, circular cacti reminiscent of a Wile E. Coyote cartoon backdrop.

Dressed in head-to-toe denim with a thick beard and mustache, owner Erik Hamline, 31, matches his desert-chic store aesthetic. He got the idea for the shop after getting compliments on his personal cacti collection. Still, he wasn’t prepared for the enthusiasm that would meet the store’s opening in March.

“I had no idea what to expect,” he said. “There’s no real baseline. But there was pretty much a line out the door.”

There is a cactus craze in the country, and millennials are driving it.

A 2016 National Gardening Survey found that 5 million of the 6 million Americans who took up gardening that year were ages 18 to 34.

Fewer millennials are buying homes, opting to rent instead, often in cities where outdoor space is limited. Houseplants offer a touch of nature. They also serve as inexpensive decor. You can pick up a plant for under $10 to add a pop of color, texture and style to a room.

But when it comes to cacti, easy maintenance may be the biggest draw.

“They’re really good plants if you’re not good at keeping plants alive,” said Madre Cacti customer Gina Gaetz, 27. “They’re my little friends.”

Hamline has found he needs to restock his supply often. But it isn’t as easy as heading to a nearby nursery.

Every five weeks, Hamline drives 1,500 miles south to Arizona, New Mexico and Texas in his 2006 Dodge Sprinter van, which he bought specially for the transporting trips. There, he works with independent growers who offer him a wider selection of plants than he could find in the North. He also likes the adventure — and being able to handpick the plants he wants.

‘A piece of sculpture’

His favorites? The weirder, the better. When going on buys, Hamline said, he often looks most at a plant’s structure, or referring to them as “a piece of sculpture.”

“I’m really into it for form at this point,” Hamline said. “I’m really into stuff that’s funkier, that doesn’t really look like it should be alive.”

Since he’s a one-man operation, he has to close the shop, at 2201 NE. 2nd St. (madrecacti.com), while he’s on buying trips. As the owner and only employee, he repots and stages the store solo, too.

“It’s a lot of sweaty, physical, manual labor,” he said. “The only way this shop works is essentially because I am the only one dumb enough to go do it.”

He has learned the benefits to bringing a bit of the outdoors inside: Houseplants provide greenery that not only brightens a space but lifts the spirits.

According to a 2010 Washington State University study, indoor plants can improve air quality, lower stress, reduce mental fatigue and increase productivity.

“Some of it is subconscious. We don’t realize that plants help us relax,” said Prof. Mary Hockenberry Meyer, who teaches horticulture at the University of Minnesota. “We know that there’s an impact even if there’s just a few plants that are inside. It creates a different feel in a room; it helps us relax and feel more comfortable.”

For Hamline, cacti have become a lifestyle.

“It’s like a complete extension of me,” he said of the shop.

“Any plant that’s in here at any given point in time, I pretty much know where it is in the shop and I remember picking it up and being like, ‘Yeah, you’re definitely coming home with me,’ ” he said.

“You become one and it becomes you.”