About 80% of the nearly 6 million rookie gardeners in 2015 were millennials, some of whom opted for a menagerie of plant pets over more traditional four-legged companions. The motivations-and the benefits-of having plants are startling similar to pet ownership. Seeing something grow from just a wee thing and thrive under your care connects you to your space, the planet and to wider community of like-minded people. (#plantsofinstagram anyone?)