Then someone threw out a datura root and the thick fleshy tree grew up and the great white bells hung down over the boiler door and at night the flowers smelled of love and excitement, an incredibly sweet and moving odor.
In 1935 Mr. and Mrs. Sam Malloy moved into the boiler. [ . . . ] True, if you came in through the fire door you had to get down on your hands and knees, but once in there was head room in the middle and you couldn't want a dryer, warmer place to stay (8.1-8.2)
Usually we think of homes as the opposite of nature. But here, even though it's dry and warm, the boiler isn't suitable to be a home until it's been gussied up with flowers and plants. Without all the plants, it would just be a rusty old hulk.