I’m not saying I have an obsession with ground covers, but I am certainly very passionate about them. Of course, it is someone else’s fault, the guilty parties in this instance being Thomas Rainer and Claudia West, the authors of Planting in a Post-Wild World. In this book they strongly advise us gardeners to pay attention to the lowest layer of the garden, which when planted provides all the benefits of mulch and more. There is much more to their case—and to the book, so I recommend reading it.

My passion for ground covers has taken the form of buying anything I see that isn’t as common as pachysandra and that spreads, but in a nice way. So I was very interested in Joann Vieira’s article “Problem-Solving Ground Covers”. It is the best kind of article in that it recommends plants I am not familiar with and now want to grow, as well as plants that I know and have always wanted to grow. The only thing missing is a few plants that I am already growing. That would let me know I am on the right track and would provide a little ego boost, too.

But I have enough ground covers now to make me ask, What is the difference between passion and obsession?

I would say you have a gardening obsession if you start gardening your neighbor’s property when your neighbor has never invited you to do so. If you end a friendship over a clem-a-tis/cle-mat-is argument, you have a gardening obsession. So, too, if you go to your favorite nursery and realize you already have every plant they sell, even the ones you don’t really like. If you grow some plants because they are uncommon, but they are equally unremarkable, you might have an obsession.

Have you crossed a line if your daughter catches you asking your newly planted Isotoma fluviatilis to “just cover that area so I don’t have worry about it”? And then when she leaves, you immediately apologize to your plants for denying that you were talking to them, pleading, “You know I didn’t mean that, right?” Maybe that is an obsession. But it isn’t a problem until the plants start talking back.

—Steve Aitken, editor