The wonderful terrarium I had planted by a local shop last year is still wonderful; it’s just different. The large fishbowl had been the home of 2 previous terrariums, part of a gift to someone who should never, ever have a terrarium.
Eventually, the bowl with its rocks and maybe one plant came back to me. I had it redone by a great local shop, Put a Plant On It. A year later, it’s time to evaluate. The plants are mainly peperomia, which come in all shapes and sizes and are generally fun little houseplants. There’s also some creeping fig. As you can see from the image above (sorry about the reflections), two of the peperomia have thrived: (best guesses on these names) the obtusifolia (large, variegated) and the orba (smaller, light green). The creeping fig is still creeping about, but two of the textured peperomia are barely showing their little faces. Clearly, an alpha peperomia has emerged and is dominating the group.
My friend wants to add one or two plants to make up for the underperformers, and we’ll likely do that, but I enjoy the terrarium as it is and find what’d developed over a year interesting. I see the same stuff happening outside all the time and I tend to be more of a watcher, always reluctant to intervene unless serious harm is being done. I’ve allowed plants like aruncus (goats beard) and eutrochium (Joe Pye) engulf and devour their competitors in their respective beds. I might get tired of their dominance and step in, as I did with the Joe Pye. It was too tall and overpowering—and I learned that with this, you either pull it all out or leave it. Anything lesser just encourages it. (Same thing with Jeana phlox.)
The takeaway: the terrarium is still mainly alive and still looks good. And I do like the obtusifolia. Let’s see what happens when we add pilea depressa, as Johanna suggests.