Roman wormwood — Artemisia pontica — always makes me think of romantic Victorian nosegays. The flowers are nothing — but the silvery foliage, more finely divided than any other I know, adds a fluffy, lacy effect to garden and bouquet. One of my all-time favorite plants — as well as perhaps the most invasive one I grow!

Currently on the second tier of the terraces in my front yard, it’s above the level where variegated periwinkle grows in a sweep of bright twinkle created by deep green leaves with white edges. I look at the way the silver artemisia echoes the white, and want to find more silver and white elements to add to this composition.

The bed is dry and sunny, with rather meager sandy soil. I don’t want to enrich it much, or the artemisia will get too tall and flop over. There’s a gap in the planting next to the artemisia, which it’s starting to creep into — but I could put something else there too. If it’s tough.

A white echinacea (purple coneflower) I think would look perfect. However some people say echinaceas are tough, but I haven’t found that. I transplanted my first one four times before I found a site it thrived in: my best bed, the one with deep humus. One nursery I asked told me the white ones in particular had not done well for them.

What appeals to me about the echinacea is not only the white flower, but also the contrast between its coarse, large scale — and the delicate artemisia. What else would do that?

Perhaps a sea holly (eryngium), with its big, spiky, thistle-like looks. Three-foot-tall E. planum ‘Silverstone’ tolerates dry soil, and has white flowers.

Silver sage could give another contrast in texture. With its eight-inch wide, elephant-ear leaves covered in white hair, this dramatic plant makes a three-foot rosette the first year, and in the second, sends up a six-foot, branched flower stalk. I’ll have to cut off the flowers before they set seed, to keep the plant from dying.

One more possibility occurs to me. There used to be a yucca plant growing in this bed. I was so happy when I eradicated it! I hated it. But it grew fine here, and exactly that coarse, ragged heft that used to put me off, now might be the perfect accompaniment for the artemisia. Y. glauca and Y. filamentosa, subspecies concava albovariegata , both have white edges on their sword-shaped leaves.

As soon as this was published, I noticed that the A. pontica was getting dried-out and brown, starting at the base of the stems and moving upward. I guess it's not such a tough plant as I thought! Time to rethink.