Only two years ago, when I was finishing my memoir of gardening obsession, “Rhapsody in Green,” I claimed that I had no time for houseplants. Prickly, diminutive, macramé-reliant: I’d rarely been less tempted by anything.

I am definitely not a hoarder. Trust me: I know. If my parents ever move house, it would be simpler to hire a wrecking ball.