Succulents, fiddle leaf figs, the elusive variegated monstera: Ask proud plant parents about their collections, and theyll gush with such enthusiasm that youd think they were talking about actual children.

Jennifer Coates, a 33-year-old freelance writer in Los Angeles, has accumulated more than 110 houseplants since she began collecting in January. Today, theyre an integral part of her daily routine. Every morning, she rolls out of bed, heads to the living room and begins a 45-minute tour of all her plants. Even before brushing her teeth or feeding the dog, Coates inspects every leaf for signs that its thirsty or threatened by pests and tends to those that require her attention.

It might seem extreme, but Coates is just one of many budding plant enthusiasts who dedicate hours a day and thousands of dollars to cultivating plant collections in their homes. But houseplants are nothing new, so why are millennials suddenly flocking to this hobby?