Stepping into my friend’s apartment recently, I was struck by how she had the place filled with plants. She has a Philodendron Goeldii, a fiddly fig, a winter cactus, devil’s ivy, a spider plant, a mini palm tree and more. They’re not small little things on corners of bookshelves. Some of them are large and imposing. They envelope the space. The couch, the TV and the other bits of furniture seem like accessories in their midst. They are merely functional, while the plants impose their presence on the room. And yet I’m not overwhelmed by it, they give the room...