Hi rb
I bought some similar Wallflowers (Erysimum) with variegated leaves several years ago, on a sale rack for $1 each. Same thing, seemed to be listed as both annual and perennial. I assumed they were annuals, and planted them to fill in a bad spot. But they are still here , years later (zone 8a near Seattle, so same climate as you). They are planted in crappy gravel-clay, on a hillside, at the top of rock retaining wall so water never puddles there. Here in Seattle, it rains Oct-April, then there is a drought and I hardly ever water them.
Some wallflowers are annuals, some perennials, some "short-lived" perennials, and some it depends on how cold it gets there, but can be either. These ones get woody stems, are really a small shrub. One year I cut them back a bit, they did not seem to mind. I have never tried chopping them back hard.
They start blooming in April, finish in November with loooooong flower stalks. At that time I cut off the silly flower stems, the leaves stay all winter, looking great!
Here they are in April, and again in November.
I really like them. I don't know if I would want them right by my front porch, the long flower stalks in the late summer are a bit weedy looking, but at the far side of my driveway the yellow flowers show up well and the weediness of the gangling stalks does not bother me at all. I also have some orange wallflowers that are perennial. The Bowles Mauve purple ones were great for two years, then did not come back, but I have seen ones that are real perennials around here, probably it was my crappy clay.
