Achillea ssp. ex Utah, with sedum, saxifrage, chamaecyparis and campanula
I must admit, I'm not a big fan of the gaudy-colored yarrows. I grow only a couple of the muted ones, like Anthea, in the garden. I do love the delicate, sculptural qualities of this little pale yellow number, achillea ssp. ex Utah. The nursery tag said it forms "small mats". It's been in the trough a year now and is only a little unruly. I hope the lean growing medium of the trough will restrain it a bit. The new campanula chamissonis (front right of photo) may push back when it gets going.